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ANATOMICAL    TECHNOLOGY 


AS    APPLIED   TO 


THE    DOMESTIC    CAT 


AN    INTRODUCTION 


TO    HUMAN,    VETERINARY,    AND    COMPARATIVE    ANATOMY 


WITH    ILLUSTRATIONS 


BY 

BURT    G.   WILDER,   B.S.,   M.D. 

PROFESSOR   OF   PHYSIOLOGY,   COMPARATIVE   ANAlXJMY   AND  ZOOLOGY   IN   CORNELL   UNIVERSITY,   MEMBER 

OF   THE   AMERICAN    NEUROLOGICAL    ASSOCIATION,    FELLOW    OF   THE   AMERICAN 

ASSOCIATION   FOR   THE   ADVANCEMENT   OF   SCIENCE,    ETC. 


AND 


SIMON   H.  GAGE,  B.S. 


ASSISTANT   PROFESSOR   OF   PHYSIOLOGY   AND   LECTURER    ON    MICROSCOPICAL   TECHNOLOGY   IN 

CORNELL   UNIVERSITY,    FELLOW   OF  THE   AMERICAN   ASSOCIATION   FOR   THE 

ADVANCEMENT   OF   SCIENCE,    ETC. 


SECOND     EDITION,    REVISED 


NEW  YORK  AND   CHICAGO 
A.     S.     BARNES     8i     COMPANY 


Copyright,  1882,  1886.    A.  S.  Barnes  &*  Co, 

ALL     RIGHTS     RESERVED. 


38^ 


PREFACE   TO   THE   FIRST    EDITION. 


This  Avork  has  grown  out  of  our  needs  as  instructors  of  students  pre- 
paring for  practical  work  in  Human,  Veterinary,  or  Comparative  Anatomy. 
Most  of  it  tias  been  employed  in  the  anatomical  laboratory  of  Cornell  Uni- 
versity for  from  one  to  four  years,  and  we  have  been  led  to  believe  that  it 
may  prove  useful  elsewhere. 

Some  of  our  laboratory  students  aim  to  be  professional  naturalists,  agri- 
culturists, or  veterinarians,  but  most  of  them  intend  to  study  Medicine  or  to 
teach  Physiology  with  other  branches  in  schools  and  colleges.  The  latter 
desire  to  gain  a  personal  acquaintance  with  the  organs  whose  functions  they 
are  to  discuss,  and  the  former  require,  in  addition,  a  familiarity  with 
anatomical  methods  and  literature;  few  of  them  have  had  any  practical 
training  in  Biology. 

The  guides  to  vertebrate  dissection  by  Straus-Durckheim,  Morrell,  Rol- 
leston,  Krause,  Huxley  and  Martin,  Foster  and  Langley,  Bernard,  Martin 
and  Moale,  and  Mojsisovics,  present  many  admirable  features,  but  four  of 
them  are  in  French  or  German,  and  none  have  fully  answered  our  require- 
ments. 

Of  the  works  above  named,  several  imply  that  either  the  frog  or  the 
human  body  has  been  previously  dissected ;  hence,  presumably,  the  brevity 
of  the  directions,  the  lack  of  descriptions  of  instruments  and  methods,  and 
the  fewness  or  absence  of  illustrations.  They  are  based  upon  the  frog, 
turtle,  dog,  rat  or  rabbit,  or  on  animals  in  general,  and  the  ordinary  anthro- 
potomical  terms  of  description,  upper,  lower,  etc.,  are  almost  uniformly 
employed.  Some  dwell  only  upon  points  of  physiological  importance,  and 
in  nearly  all  the  references  to  other  publications  are  few  and  general. 

95274 


IV  PREFACE, 

So  far  as  we  are  aware,  this  work  differs  from  the  manuals  above  men- 
tioned in  one  or  more  of  the  following  particulars : — 

It  assumes  no  previous  anatomical  knowledge  or  experience,  yet  is  rapidly 
progressive,  introducing  in  succession"  bones,  muscles,  viscera,  vessels,  nerves, 
brain  and  organs  of  sense. 

It  is  based  upon  the  domestic  cat  {see  §  124).  The  terms  of  description 
and  designation  apply  to  all  vertebrates  (§  38) ;  they  are  technical  (§  29), 
and  precision  and  brevity  have  been  especially  regarded  in  their  selection, 

The  purely  descriptive  portions  are  subordinated  to  the  practical  and 
directive.  There  is  a  General  List  of  the  instruments  and  materials 
required  for  ordinary  anatomical  work  (§  130),  and  directions  are  given 
for  their  care.  All  directions  for  dissection  and  manipulation  begin  with 
special  lists  of  the  instruments  and  materials  required  (§  235).  Explicit 
instructions  are  given  for  coarse  injections,  for  the  preparation  of  hones,  and 
for  the  iise  of  alcohol  as  a  preservative. 

Certain  regions  and  organs  are  quite  fully  discussed,  while  others  are 
briefly  mentioned  or  omitted  altogether  (§  128).  Unusual  space  is  given  to 
the  viscera  (§  129).  The  study  of  the  brain  includes  a  consideration  of  the 
typical  vertebrate  brain,  descriptions  and  dissections  of  the  brains  of  the 
frog  and  the  Menobranchus,  and  an  approximately  complete  Descriptive 
List  of  the  encephalic  parts,  with  References  and  Synonyms. 

There  are  illustrations,  and  the  methods  of  making  the  preparations 
figured  are  fully  described.  The  abbreviations  are  of  the  technical  names 
only,  and  they  are  nearly  uniform  throughout.  As  far  as  possible,  the 
technical  names  are  written  in  full  upon  the  figures.  In  the  explanations 
of  the  figures,  the  technical  names  and  the  abbreviations  are  alphabetically 
arranged  (§33). 

There  are  numerous  Alphabetical  Lists,  Tables  of  Synonyms  and  Tabular 
Arrangements  of  names  according  to  the  relations  of  parts  (p.  xxvi). 

Attention  is  called  to  the  incompleteness  of  our  information  upon  cer- 
tain points. 

There  are  frequent  cross  references  and  numerous  definite  references  to 
other  pubHcations  (§  2) ;  the  titles  of  the  works  and  papers  cited  (three  hun- 


PREFACE,  V 

dred  and  thirty  in  nnnit)er)  are  given  in  an  Alphabetical  List  of  Authors 
at  the  end. 

While,  therefore,  the  book  is  designed  jprimarily  as  a  guide  for  beginners, 
certain  features — the  references  and  the  suggestions  as  to  lines  of  inquiry — 
may  prove  useful  to  teachers  and  others  who  may  undertake  to  add  to 
existing  knowledge. 

Histological  facts  and  methods  do  not  come  within  the  scope  of  the  work, 
but  at  the  close  of  the  discussion  of  most  of  the  organs  is  given  a  summary 
of  (A)  the  obvious  or  macroscopic  structure — that  which  may  be  determined 
with  the  unaided  eye,  and  (B)  the  fine  or  microscopic  structure.  The  latter 
is  in  no  sense  complete-  It  embraces  only  the  points  upon  which  most 
standard  authors  are  agreed  and  which  may  be  demonstrated  without  a 
great  expenditure  of  time.  Only  the  structure  of  the  given  tissue  is  con- 
sidered ;  hence  the  presence  of  vessels  and  nerves  is  not  mentioned.  If  it 
be  desired  to  carry  the  histological  inquiry  farther,  the  works  of  Quain, 
Strieker,  Ranvier,  Beale,  Frey,  and  the  special  papers  therein  referred  to,  are 
recommended. 

Among  the  many  friends  who  have  aided  or  encouraged  us,  our  thanks 
are  especially  due  to  Professor  Oliver  Wendell  Holmes  for  helpful  criticism 
of  the  terminology  and  for  suggesting  the  preparation  of  a  manual  in  which 
it  should  be  incorporated  ;  to  our  colleague.  Professor  J.  H.  Comstock,  and  to 
Professors  E.  0.  Spitzka  and  T.  B.  Stowell  for  valuable  suggestions  and 
for  the  adoption  in  their  writings  of  the  descriptive  terms  herein  employed ; 
also  to  the  last  named  for  a  critical  revision  of  the  early  manuscript  of  the 
muscles,  and  for  the  important  additions  to  knowledge  contained  in  his 
recent  paper  on  the  vagus  nerve  of  the  cat.  To  all  of  our  laboratory  stu- 
dents we  are  indebted  for  aid,  suggestions  and  criticisms,  and  especially  to 
those  (see  end  of  Bibliography)  who  have  selected  parts  of  the  cat  as  subjects 
of  their  graduation  theses. 

Our  acknowledgments  are  here  made  to  the  American  Philosophical 
Society  for  the  use  of  the  four  lithographic  plates,  and  to  the  firms  named 
in  the  List  of  Illustrations  for  the  courteous  loan  of  electrotypes  of  instru- 
ments manufactured  by  them. 

The  original  figures  were  drawn  by  the  persons  named  in  the  Note  pre- 
ceding the  List  of  Illustrations.    The  three  ladies  have  also  been  our  stu- 


1^  PREFACE. 

dents,  and  have  shown  more  than  ordinary  interest  in  their  work.  Most  of 
the  original  drawings  were  made  by  our  colleague,  Professor  E.  C.  Cleaves, 
whose  skill,  patience,  and  accuracy  only  artists  and  anatomists  can  fully 
appreciate. 

There  has  been  constant  cooperation  throughout,  but,  it  may  be  proper 
to  state,  the  senior  author  holds  himself  particularly  responsible  for  the 
Introduction,  the  Preservation  of  Soft  Parts,  the  Bones  of  the  Limbs,  the 
Muscles,  the  Heart,  the  Central  Nervous  System  and  the  Cranial  Nerves ; 
and  the  junior  author  for  the  Preparation  of  Bones,  Coarse  Injections,  the 
Skeleton  excepting  the  limbs,  the  Viscera,  the  Peripheral  Vascular  and  Ner- 
vous Systems  and  the  Organs  of  Sense. 

Notwithstanding  our  efforts  for  accuracy,  there  are  doubtless  errors  of 
observation  and  interpretation.  Corrections  or  suggestions  will  be  gladly 
received. 


PREFACE    TO    THE    SECOND    EDITION. 


From  their  own  experience  and  from  the  testimony  of  teachers  and 
students  elsewhere,  the  authors  beheve  that  this  work  answers  the  purpose 
for  which  it  was  written,  viz.:  to  furnish  those  who  intend  to  pursue  human, 
veterinary,  or  comparative  anatomy  with  explicit  directions  for  dissection  and 
for  the  preparation  and  preservation  of  anatomical  specimens,  and  with  a 
correct  and  clear  account  of  the  principal  parts  of  an  accessible  and  fairly 
representative  mammal  of  convenient  size. 

Although  arranged  for  the  convenience  of  beginners,  the  figures  and 
descriptions  are  based  upon  repeated  dissections  by  the  authors,  and  thus 
constitute  an  original  monograph  upon  the  anatomy  of  the  cat,  serviceable 
for  comparison  in  researches  upon  other  forms. 

The  errors  and  oversights  detected  in  the  first  edition  have  been  corrected 
in  this,  and,  in  accordance  with  the  progress  of  anatomical  knowledge  and  a 
change  of  the  authors'  views  upon  certain  points,  some  new  matter  has  been 
added  and  some  of  the  old  restated.  The  more  important  changes  are  as 
follows : 

1.  Four  figures  have  been  replaced  by  others  representing,  respectively, 
the  entire  neuron  in  horizontal  section  (Fig.  110,  p.  408) ;  the  mesal  aspect 
of  a  brain  separated  into  its  five  encephalomeres  (Fig.  117,  p.  444a);  the 
mesal  aspect  of  a  brain  lacking  the  callosum  (Fig.  118,  p.  449) ;  a  transection 
through  the  medicommissure  (Fig.  122,  p.  458). 

2.  Three  Tables  have  been  revised,  viz.:  Names  and  Synonyms  of  the 
encephalic  segments  (p.  405);  Names  of  the  Principal  Parts  of  the  Amphib- 
ian Brain  (p.  409);  List  of  Names  and  Abbreviations  (pp.  436-438). 

3.  Sixteen  pages  of  new  matter  have  been  introduced,  viz.:  (a)  The  use 
of  shps  in  scientific  correspondence  (p.  52).  (b)  The  use  of  peroxide  of 
hydrogen  in  bleaching  bones  (p.  Ill),  (c)  The  methods  of  starch  injection 
(leaflet  between  pp.  140-141).  (d)  A  revision  of  the  method  of  injecting  the 
lacteal  trunks  and  thoracic  duct  (p.  364).  (e)  A  description  of  the  new  figure 
110  (p.  410).  (/)  A  detailed  description  of  the  new  figure  117  of  the  mesal 
aspect  of  the  brain  (pp.  446-448).  (g)  A  commentary  upon  Chapter  X 
(pp.  400«-400(?)  in  respect  to  the  structure  and  names  of  certain  parts,  the 
general  constitution  of  the  brain  and  its  preparation  by  the  injection  of 


lY  PREFACE. 

Miiller's  fluid,  or  of  alcohol  into  the  vessels  or  cavities,  {h)  References  to 
the  writers  who  have  adopted  the  new  terms  of  designation  and  description 
(p.  534).  {i)  A  supplementary  index,  (j)  A  list  of  additional  references  to 
publications. 

The  following  is  a  nearly  complete  list  of  the  minor  changes  and  typo- 
graphical corrections  made  in  the  present  edition : 

P.  75,  lines  9-11  read  :  Messrs.  Schuyler  &  Co.,  and  White  &  Burdick,  of  Ithaca,  for 
$6.35.  It  contains  the  following  instruments  :  Three  assorted  scalpels,  coaree  and  fine 
forceps,  coarse  and  fine  curved  scissors,  arthrotome,  tracer  and  blow-pipe. 

P.  159,  §  410,  4th  line.     For  caudal  portion,  read  cephalic  part. 

P.  164,  §  429,  11th  line.     Read :  diapophysis  of  the  corresponding  thoracic  vertebra. 

P.  184, 12th  and  13th  lines.  Read :  It  passes  along  the  carotid  canal  and  unites  with  a 
larger  vessel  extending  along  the  mesal  side  of  the  bulla. 

P.  202.  For  6  read  :  Have  plenty  of  light  upon  the  part  under  dissection  so  that 
details  of  structure  may  be  seen. 

P.  238,  §  649.     Under  General  Description,  for  dorsimeaon,  read  ventrimeson. 

P.  264,  §  686.  Under  Origin,  10th  and  11th  lines,  for  radial  artery  and  nerve,  read 
brachial  artery  and  median  nerve. 

P.  264,  §  687.  Under  Origin,  7tli  line,  for  radial  artery  and  nerve,  read  A.  hrachialia 
and  N.  medius. 

P.  277,  §  713,  3d  line.     For  thorax,  read  abdomen. 

P.  365,  §  991,  last  line.     For  dorsad  of  the  aorta,  read  dorsad  or  ventrad  of  the  carotid. 

P.  386,  §  1026,  4th  line.     For  Ist  cervical,  read  7th  cervical. 

In  each  of  the  three  following  places,  for  root,  read  trunk  :  p.  388,  last  line  ;  p.  389, 
first  line ;  p.  395,  §  1043,  5th  line. 

P.  512,  §  1399,  line  22,  add  :  on  the  side  of  the  face,  in  the  ventral  lip. 

P.  489,  §  1324,  5th  line.     For  caudal,  read  ventral. 

P.  522,  §  1424,  9th  line,  and  p.  525,  8th  line.     For  macula  lutea,  read  discus  opticus. 

In  respect  to  nomenclature  the  authors  are  assured  that  the  innovations 
embodied  in  the  first  edition  were  in  the  line  of  real  and  natural  progress.  The 
descriptive  terms  apply  equally  to  all  vertebrates  and  the  terms  of  designa- 
tion are,  for  the  most  part,  brief,  capable  of  inflection,  and  equally  intelligible 
to  anatomists  of  all  nations.  They  realize,  however,  that  the  use  of  words 
with  obviously  Latin  terminations,  even  when  the  terms  are  more  or  less 
familiar,  imparts  to  a  sentence  a  decidedly  un-English  look,  and  that,  for 
most  readers,  the  technical  Latin  names  would  be  more  acceptable  if  in  an 
English  dress,  or  with  a  vernacular  face  and  aspect. 

In  accordance,  therefore,  with  considerations  more  fully  presented  in  the 
senior  author's  paper  {64:),  the  desirable  English  appearance  of  the  newly 
added  pages  has  been  attained,  not  by  reverting  to  English  translations  or 
heteronyms  of  the  Latin  names,  but  by  converting  the  latter  into  their 


PREFACE.  Y 

natural  English  paronyms.*  For  example,  myelon  becomes  myel  (adjective 
iiiyelic)  ;  mesocmlia,  mesocoele;  pedunculus,  peduncle,  Qic. 

To  have  paronymized  all  the  names  would  have  involved  resetting  the 
entire  work.  Examples  may  be  found  upon  the  new  figures  110  and  117, 
upon  pages  400rt-400c/,  and  in  the  following  list : 

List  of  names,  mostly  encephalic,  illustrating  the  methods  of  reducing 
Latin  polyonyms  to  mononyms,  of  converting  Latin  mononyms  into  English 
paronyms,  and  of  forming  adjectives  therefrom  : 


LATIN. 
Polyonyms. 

Pars  media  ventricuU  communis. 

Hippocampus  minor 

Corpus  callosnm 

Nucleus  caudatus 

Tract  us  transversus  pedunculi. . . 

Substantia  cinerea 

Processus  clavatus 

Musculus  coracoideo-brachialis. .  . 
Plexus  choroideus  ventricuU  tertii 

Musculus  pectoralis   externus    s 

major 

Pia  mater  interior 

Fascia  dentata 

Corpus  fimhriatum 

Comrnissura  fornicis , 

Fornix  cerebri 

Hippocampus  major 

Insula  Reilii 

Iter  a  tertio  ad  quartum  ventric- 

ulum 

Foramen  infundibuli 

Arteria  cerebralis  media 

Comrnissura  media 

Ventriculus  mesencephali 

Ventriculus  quartus 

Tela  choroidea  inferior 

Chorda  spinalis 

Medulla  oblongata , 

Pia  mater 

Pons  Varolii 

Foramen  Monroi 

Vena  cava  posterior 

Cornu  j)osterius  ventricuU  later 
alis 


ENGLISH. 

Mononyms. 

Paronyms. 

Adjectives. 

Aula 

Aula 

Aullc. 

Calcar 

Calcar 

Calcarine. 

Callosum 

Callosum 

Callosal. 

Gaudatum 

Caudatum 

Caudatal. 

Cimbia 

Cimbia 

Cimbial. 

Cinerea 

Cinerea 

Cinereal. 

Clava      .  . 

Clava 

Claval 

Coracoideus  

Coracoid    .... 

Coracoid. 

Diaplexus 

Diencephalon 

Diaplex 

Diencephal 

Diaplexal. 
Diencephalic. 

Ectopectoralis . . . 

Endyma 

Fasciola 

Ectopectoral. . 

Endyma 

Fasciola 

Ectopectoral. 

Endymal. 

Fasciolar. 

Fimbria 

Fimbria 

Fimbrial. 

Fornicommis- 

Fornicom- 

sura 

missure 

Fornicommissural. 

Fornix 

Fornix 

Fornical. 

Hippocampus  . . . 
Insula 

Hippocamp. . . . 
Insula 

Iter       

Hippocampal. 
Insular 

Iter     

Iteral 

Lura 

Lura. 

Lural 

Medicerebralis. . . 

Medicerebral. . 

Medicerebral. 

Medicommissura. 

Medicommis- 

sure 

Medicommi  ssural . 

Mesocmlia 

Mesocoele 

Mesoccelian, 

Metepiccelia 

Metatela 

Metepicoele  . . . 
Metatele 

Metepiccelian. 
Metatelar. 

Myelon 

Myel 

Myelic. 
Obi  ongatal. 
Pial. 

Oblongata 

Pia 

Oblongata 

Pia    

Pons 

Pons 

Pontile. 

Porta 

Porta 

Portal. 

Postcava 

Postcava 

Postcaval. 

Postcornu 

Postcornu 

Post  corn  ual. 

*  The  terms  paronym  and  heteronym  were  suggested  by  our  colleague,  Prof.  Isaac 
Flagg.  Paronym  (compare  the  Greek  Trapuvvula)  indicates  a  name  which  is  cognate  with 
or  radically  allied  to  another ;  heteronym  is  its  natural  correlative  and  implies  the 
absence  of  such  relationship.  For  example,  canal  is  the  paronym  of  canalis,  while  its 
heteronyms  are  groove,  furrow,  aqueduct,  etc. 


VI 


PEE  FACE, 


LATIN. 

ENGLISH. 

Polyonyms. 

Mononyms. 

Paronyms. 

Adjectives. 

Nares  posteriores 

Postnares 

Proecentralis 

Prcepedunculus. . 

Proeoelia 

Pseudoccslia 

Subfrontalis 

Superoccipitale . . 
Terma 

Postnares 

Precentral.   . . . 
Prepeduncle . . . 

Procoele 

Pseudocoele.. .. 

Subfrontal 

Superoccipital. 

Terma 

Thalamus 

Valvule 

Ventricornu  . . . 

Postnarial. 

Fissura  centralis  anterior 

Pedunculus  cerebelli  superior. . . 
Ventriculus  lateralis 

Precentral. 

Prepeduncular. 

Procoelian. 

Ventriculus  ouintus 

Pseudocoelian. 

Gyrus  frontalis  inferior  s.  tertius 
Pars  superior  ossis  occipitalis  . . . 
Lamina  terminalis 

Subfrontal. 

Superoccipital. 

Termatic. 

ThalaTnus  opticus     

Thalamus 

Valvula 

Venti'icornu .... 

Thalamic. 

Valvula  Vieussenii 

Valvular. 

Coma  anterius  s.  ventrale  myel- 
onis 

Ventricornual. 

The  method,  paronymization,  applies  to  other  languages  ;  e.  g.,  from  the 
Greek  TTvpdiil^,  we  have  the  Latin  pyramis,  the  English  pyramid,  the 
French  and  German  pyramide,  and  the  Italian  piramide ;  so  the  Greek 
eyice(l)dAog  becomes  L.  encephalum  or  encephalon,  E.  encephaly  G.  encefal, 
F.  encepliale,  and  I.  encefalo. 

In  view  of  the  above  examples  there  seems  good  ground  for  hoping  that 
the  recognition  of  the  principle  of  parony ray  may  facilitate  the  establishment 
of  a  universal  scientifin  language,  combining  with  the  perfection  of  Latin 
construction  a  far  greater  richness  and  precision. 

As  a  whole,  then,  the  vocabulary  which  seems  to  us  best  calculated  to 
facilitate  the  advancement  and  dissemination  of  accurate  anatomical 
knowledge  may  be  contrasted  with  that  which  is  in  common  use  as  consist- 
ing of  terms  which  are  : 

Designatory  rather  than  descriptive. 

Vertebrate  rather  than  human. 

Restricted  rather  than  unrestricted. 

Correlate  rather  than  irrelate. 

Co-ordinate  rather  than  inco-ordinate. 

Classical  rather  than  vernacular. 

Dissyllabic  or  trisyllabic  rather  than  monosyllabic  or  polysyllabic. 

Mononymic  rather  than  polyonymic. 

Paronymic  rather  than  heteronymic. 
The  authors  desire  to  express  their  sense  of  obligation  to  Dr.  Spitzka  for 
Fig.  118;  to  Messrs.  D.  Appleton  &  Co.,  for  the  use  of  Figs.  110,  117,  122; 
to  many  friends,  especially  students,  past  and  present,  for  helpful  criticism  ; 
to  the  reviewers  for  their  courtesy  toward  what  was  in  some  respects  a 
departure  from  established  customs  ;  and  finally  to  the  publishers  for  the 
liberality  with  which  they  have  seconded  the  efforts  to  render  the  work  a 
substantial  contribution  to  science. 


CONTENTS 


IKTEODUCTION. 

PAGE 

References  to  Publications 1-3 

Method  of  reference  to  authors 3 

Catalogue  of  scientific  papers  published  by  the  Royal  Society  of  London  . .  3 

Decimal  Systems 3-8 

Centigrade  TJiermometer— Fahrenheit' s  Thermometer 3 

Comparison  and  reduction  of  the  two  thermometric  scales 3 

Table  of  equivalent  temperatures  according  to  the  Fahrenheit  and  Centi- 
grade thermometers 4 

Formulae  for  the  reduction  of  the  Fahrenheit  and  Centigrade  scales  and  vice 

versa 4 

Ths  Metric  System 4-8 

Meter,  liter  and  gram — definitions  and  common  equivalents 4 

Comparison  of  the  metric  and  English  systems  of  weights  and  measures. . .  5 

Table  of  the  metric  measures 5 

How  to  learn  the  metric  system 6 

Table  of  equivalents  of  metric  and  English  measures 7 

The  metric  system  in  medicine 8 

Zoological  Classification 8 

Table  illustrating  classification 9 

Terminology 10 

Character  of  the  terminology  here  used 10 

General  considerations  upon  anatomical  terminology 11 

Aphorisms  upon  terminology  from  various  sources 13 

Brief  statement  of  the  objects  and  methods  of  the  terminological  changes 

here  made 13 

Designation  of  Organs — Organonymy 14 

I         General  considerations  by  various  authors 14 

Importance  of  brevity 15 

Comparison  of  technical  and  vernacular  terms  in  science 15-17 

Ease  in  acquiring  technical  terms 17 

Names  indicative  of  relative  position 17 

The  limits  of  terminological  change 18 

Priority  and  etymological  appropriateness  of  technical  terms 18 

Some  inconsistencies  in  the  nomenclature  here  adopted 19 

Names  and  abbreviations  on  1j^e  figures  20 


Viii  CONTENTS. 

PAGE 

Terms  of  Position  and  Direction — Toponymy 20 

The  normal  position  of  the  body 21 

Designation  of  the  aspects  of  animals 21 

Views  of  Barclay  and  others  21-22 

Ambiguity  of  terms 22 

Intrinsic  Toponymy 23 

Cephalic  and  caudal,  dorsal,  ventral,  dextral,  sinistral,  lateral  and  mesal — 

signification  and  use  by  various  authors 23-24 

Ventrimeson,  dorsimeson,  intermediate  and  medial 25 

Designation  of  the  Regions  of  the  Limls 25 

Proximal  and  distal  extremities 25 

Cephalic  and  caudal,  dorsal  and  ventral  aspects 25-26 

Other  names  for  the  extremities  and  aspects 26 

Terms  of  General  Application  to  the  Whole  Body 26 

Centraland  peripheral,  ectal  and  ental 26-27 

Inflections,  etc 27 

Adjective  endings 27 

Use  of  the  prepositions  of  and/rom 27 

Limitations  of  accuracy • 27 

Derivatives,  connecting  vowels  of 28 

Compound  words — Hybrid  words 28 

Primary  Divisions  of  the  Body — Soma  and  Membra 29 

Axial  portion,  soma — Appendicular  portion,  membra — Truncus  or  trunk. .  29 
Comparison  of  right  and  left  (dextral  and  sinistral)  in  the  object  and  the 

observer , 29-81 

Position  and  direction  on  the  soma 31 

Columna  vertebral  is,  its  constitution  and  location 32 

Canalis  neuralis  and  coelum  or  general  body  cavity 33 

Essential  characteristic  of  all  vertebrates 33 

Body  Planes 88-34 

Meson 33 

Paired  or  Lateral  Organs — Azygous  or  Mesal  Organs 33,  43 

Designation  of  Position  and  Direction 34 

Direct  lines — Oblique  lines 34 

Designation  of  direct  and  oblique  lines 34-35 

Designation  of  position  on  oblique  and  direct  lines 35 

Designation  of  diagonal  lines 35 

Designation  of  the  relative  position  of  points  on  diagonal  lines 36 

Designation  of  Direction  and  Relative  Position  on  the  Limbs 36 

Ental  and  ectal  and  their  derivatives 36 

The  soma  and  its  divisions — Head,  neck,  trunk  and  tail 36 

The  trunk  and  its  divisions — Thorax,  abdomen  and  pelvis 36-37 

Partition  between  the  abdomen  and  thorax 37 

Coelum  or  trunk  cavity 37 

Table  of  the  divisions  of  the  body 39 

Normal  Position  of  the  Limbs 37 

Limb  Segments  and  the  Arthra  or  Joints 40 

Limb  bones 40 

Carpus  and  tarsus . .. .' 41 


CONTENTS.  IX 

PAOB 

Intermembral  Homologies 43 

Syntropy  and  antitropy 43 

Enumeration  of  Parts  in  a  Series 43 

Use  of  Terms  of  Relative  Position  in  a  Physiological  Sense 44 

Slip  System  of  Notes 45-53 

Slips — Size,  etc. — Making  notes  on 45 

Library  catalogues  and  catalogue  data  for  specimens 46 

References,  extracts,  clippings  and  notes  proper 47 

Accumulation  and  elimination  of  slips 47 

Arrangement  and  storage  of  notes 48 

Subdivision  of  notes,  with  Table 48-49 

Distribution  of  slips 50 

Method  of  using  slips 50 

Portfolios  for  slips  and  sheets 48-51 

Miscellaneous  suggestions  as  to  the  use  of  slips 51 

Origin  of  the  slip  system 53 

Rules  and  Aphorisms  of  General  Application  in  Biology 52-53 

Anatomical  Technology— Introductory 55 

Beasonsfor  Selection  of  the  Gat  for  Anatomical  Study 55 

Importance  of  methods 55 

Comparison  of  the  cat  as  an  anatomical  subject  with  adult  human  beings, 

still-born  children,  horse,  rabbit,  dog,  rat,  opossum 55-57 

Needs  of  a  standard  of  comparison  for  comparative  anatomists 56 

Beasonsfor  treating  of  only  a  Part  of  the  Body 57 

Beaaons  for  giving  unusual  Prominence  to  the  Viscera 58 


CHAPTEK    I. 

INSTRUMENTS  AND  MATERIAL  FOR  ANA.TOMICAL  TECHNOLOGY. 

Alphabetical  list  of  instruments  and  materials  needed  for  anatomical  technology, 

with  prices 59-63 

Dealers'  catalogues  of  instruments  and  materials 59 

General  Character  of  Instruments 63 

Description  of  Instruments  and  Material 62-73 

Arthrotome  and  beaded  bristles 63-63 

L Supporting  blocks,  flexible  blow-pipe. . .  64 
Cats — Price,  care,  storage,  etc 64-65 
Chain-hooks,  small  compressor  and  dissecting  gown 65 
Drawing  materials,  foot  lathe  and  drills,  forceps  (coarse  and  fine),  nippers 
for  cutting  bone 67 
Dropping- bottle  oiler,  parchment  labels,  nibber  gloves  and  tubing,  saw. . .  68 
Scales  and  special  weighing  pan,  scalpels 69 
Scissors  and  sponges 70 
Syringotome,  tags  for  labels,  tools,  towels,  tracer  (seeker  or  finder),  sharp 
and  blunt 71 


X  CONTENTS. 

PAGE 

Wetting  bottle  for  15  per  cent,  glycerin,  waste  paper  for  particles  made 

in  dissecting 73 

Care  of  Instruments 73-74 

Special  directions  for  blow-pipe,  tray,  forceps,  nippers,  saw,  scissors,  scal- 
pel, and  cutting  instruments  generally 74 

Cases  and  Trays  for  Instruments 74 

Packing  Instruments  for  Transportation 75 

Polishing  Instruments 75-76 

Sharpening  Instruments 76-79 

Honing  and  stropping 76 

Determination  of  sharpness 78 

Killing  Animals  for  Dissection 79-81 

Drowning,  killing  with  chloroform  or  ether  in  a  box 80 

Anaesthetic  box 81 

EJUling  Fleas  with  Benzine 80 

Precautions  for  Cleanliness,  Comfort  and  Health 81-86 

Waste  paper,  waste  pail  and  waste  pit 81-82 

Washing  sink 82 

Deodorizers  —  Animal  charcoal,  alcohol,  potassium  permanganas,  sul- 
phate of  iron 83 

Malodorous  parts  to  be  promptly  removed . .  / 84 

Dissection  Wounds— Precautions  and  Treatment 85 


CHAPTER    II. 

GENERAL    DESCRIPTION  OF    THE    SKELETON,  ANATOMICAL    LANDMARKS 
AND  ABDOMINAL  TRANSECTION. 

General  Description  of  the  Skeleton 87-95 

Components  of  the  skeleton 87 

Somatic  or  Axial  Parts  of  the  Skeleton 87 

Skull  and  vertebraB 89 

Costae  or  ribs,  sternum,  scapula  and  clavicle •  •  • 90 

Pelvis,  Shoulder  and  Hip  Joints,  Wrist  B.nd  Ankle 91 

Membra  or  Appendicular  Parts  of  the  Skeleton 91 

Bones  of  the  limbs 91 

Normal  position  of  the  limbs 92 

Position  of  the  arthra  or  joints  in  the  limbs 93 

Os  hyoides  and  larynx 94 

Anatomical  landmarks 95-98 

Mesal  Somatic  Landmarks 95 

Lateral  Somatic  Landmarks 96-97 

Membral  Landmarks 97-98 

Abdominal  Transection 98-102 

Parts  involved 99 

Preservation  of  the  CepMlic  Half  of  the  Transected  Body 101 

Thoracic  Transection 102 


CONTENTS,  X\ 

CHAPTEE    III. 

PREPARATION  AND  PRESERVATION  OF  ANATOMICAL  SPECIMENS. 

PAGE 

Preparation  of  Bones 103-111 

General  directions •  • 103 

Removing  soft  parts  from  alcoholic  specimens 105 

Removal  of  soft  parts  by  ants  or  Dermestes 105 

Putrefactive  maceration  in  water 105 

Boiling  in  liquid  soap 106 

Preparation  of  SkuUs 107 

Cements  for  Bones  and  Teeth 107 

Preparation  of  Natural  Skeletom 108-109 

Flexible  natural  skeletons 109 

Preparation  of  the  Bones  of  Toung  Animals 109 

Disarticulating  Skulls 109 

Bleaching  Bones 110 

Preservation  of  Soft  Parts 111-131 

Agents  preventing  decomposition Ill 

Ethyl  Alcohol — Absolute  and  Commercial 113 

Table  of  percentages  of  alcoliol 113 

Leading  characteristics  of  alcohol 113 

Inflammability  of  alcohol  and  precautions  against  fire 114 

Determination  of  percentages  of  alcohol  with  the  alcoometer 114 

Determination  of  and  changing  the  percentage  of  alcohol 115 

Table  of  the  amount  of  alcohol  and  water  to  mix  in  order  to  obtain  a 

required  percentage 116 

Kind  of  water  to  mix  with  alcohol 116 

Use  of  Alcohol  in  Preserving  Animals 117-131 

Bleeding  the  animal 117 

Opening  the  abdomen  and  expelling  the  faeces 118 

Injection  of  alcohol  into  the  thorax  and  abdomen 118 

Injection  of  alcohol  into  the  lungs,  stomach  and  intestines 119 

Injection  of  the  arteries 119 

Treatment  of  Special  Animals,  Organs  and  Tissues 120 

Amount  of  Alcohol  required  for  a  Specimen 121 

Provisional  Preparations 121 

Deterioration  of  Alcohol 123 

Purification  of  alcohol  by  settling  and  filtration 123 

Alcohol  Vapor  as  a  Preservative 123 

Methyl  Alcohol  or  Wood  Spirit 124 

Wickersheimer's  Preservative  Fluid 124 

Chloral  Hydrate 124 

Brine 125 

Temporary  Storage  of  Alcoholic  Specimens 125 

Leakage  and  evaporation 125 

Glass  dishes  and  boxes  for  specimens 126 

^^  ExJdbition  or  Permanent  Storage  of  Alcoholic  Specimens 1^6 

M'~~ " 


Xll  CONTENTS* 

PAGE 

Glass  jars 127 

Glass-stoppered  and  welted  vials 128 

Cleaning  glass  jars 128 

Display  of  alcoholic  specimens 129 

Packing  Alcoholic  Specimens  for  Transportation 129-130 

Frozen  Sections  and  Dissections 131-132 

Preparation  of  the  animal   for  freezing — Making  and  preserving  the 

sections 131 

Frozen  dissections 132 

Flexible  preparation  of  muscles 132 

Preparation  of  Hollow  Viscera 132-135 

Removal  of  the  viscus 132 

Cleaning,  trimming  and  inflation  with  alcohol 133 

Poisoning,  inflation  with  air  and  drying 134 

Preparation  of  the  viscera  after  drying 135 

Measuring  the  Ca/pacity  or  Volume  of  Organs 135 


CHAPTER    IV. 

COARSE    INJECTIONS. 

Object  of  injections 137 

Syringe— Care  of  syringe,  white  metal  syringe 137 

Canulas  and  preparation  of  glass  canulae 138 

Brass  anatomical  syringes 139 

Injection  Masses 139-141 

Plaster  of  Paris  Mass 139 

Carmine,  Berlin  blue  and  various  colors  for  staining  plaster 139 

Preparation  of  plaster  injection  masses 140 

Wax  and  Tallow  Masses 141 

Practical  working  of  wax  and  tallow  injections 141 

Choice  of  Specimen  and  Time  for  Injection 141 

Arteries  and  veins  to  inject 142 

Injection  of  Femoral  Vessels 142-146 

Posture  and  exposure 142 

Parting  the  hair  and  isolating  the  vessels  ... 143 

Incision  in  the  vessel — Ligatures  and  introduction  of  the  canula 143-145 

Making  the  injection — Tying  the  vessel 145-14G 

Cleaning  the  syringe  and  canula 146 

Injection  of  the  Abdominal  Aorta  and  of  the  Postcava 147 

Injection  of  the  Jugular  Vein  and  the  Carotid  Artery.. 147-148 


CHAPTEE    V. 

OSTEOLOGY,  THE  STUDY  OF  THE  BONES. 

Determination  of  Right  and  Left  with  Certain  Bones 149-151 

Position  of  the  bones 149 

Determination  of  Bight  and  Left  with  Entire  lAmbs 151-152 


CONTENTS.  Xlll 

PAGK 

l^ecial  Mnemonics  of  the  Humerus 153 

Description  of  Bones 153-189 

Scapula  (shoulder  blade) 153-156 

Humerus  (bone  of  bracliium  or  "  upper  arm  ") 157-161 

Carpalia  (wrist  bones) 161 

Clavicula  (clavicle  or  collar  bone) 163 

Sternum  (breast  bone) 163 

Costae  (ribs)  and  costal  cartilages 163-167 

Ligamentum  interarticulare  and  Comparison  mth  that  of  Man 165,  166 

Pelms 167-169 

Ilium,  ischium,  Os  cotj'loideum,  Os  innominatum,  Os  pubis. 168 

Sacrum 169 

Columna  vertebralis 169-173 

Regions  of  the  vertebral  column 170 

Distinguishing  the  groups  of  vertebrae 170 

Skull  173-191 

Cranium  and  face 174 

Sutures 1 74 

Table  of  the  Bones  of  the  Skull 174-176 

Table  of  Articulations  of  the  Bones  of  the  Skull 176-179 

Description  of  the  dorsum  of  the  skull 179-183 

Description  of  the  base  of  the  skull 183-185 

Description  of  the  tympanic  bulla 185 

Description  of  the  mesal  aspect  of  the  skull 185-186 

Description  of  the  lamina  cribrosa 187 

Description  of  the  mandible  (lower  jaw) 188-189 

Table  of  the  Foramina  and  Canals  of  the  Skull,  with  Traversing  Structures,  etc.  190 

Structure  of  Bone 191 


CHAPTER    VI. 

MYOLOGY,  STUDY  OF  THE  MUSCLES. 

General  Considerations 193 

Variation  in  muscles 193 

Errors  of  manipulation  and  interpretation 193-194 

Technical  Terms  of  Myology 194 

Muscular  groups — Subdivisions 194-195 

Parts  of  a  muscle , 195 

Attachment  lines  and  areas 195 

Origin  and  insertion — Choice  of  origin  and  insertion 195 

I         Determination  of  muscular  homologies 196 

Fascia 196 

Forms  of  muscles 196 

Designation  of  the  borders  of  muscles 197 

Aphorisms  for  Dissectors 197-198 

How  to  use  Dissecting  Instruments 199-301 

Practical  Suggestions  to  Dissectors 301 

Choice  of  specimen  and  removal  of  superfluous  parts 301 


XiV  CONTENTS, 


References  to  the  skeleton 20 

Incisions 202 

Vessels  and  nerves  and  action  of  muscles 202 

Transection  of  muscles 203 

Covering  and  moistening  parts  under  dissection 203 

Common  faults  of  dissectors 203 

Clipping  the  hair,  cutting  and  removing  the  skin 204-205 

Rigor  mortis 205 

Description  of  Certain  Muscles 206-271 

Methods  pursued 206 

Errors  and  defects 206 

Names  of  the  muscles. . 206 

Table  of  the  muscles  treated,  with  synonyms 207 

Trapezius  Group 20&-217 

General  remarks. 208 

Exposure  of  the  trapezius  muscles 210 

Attachments  of  Muscles  to  the  Humerus 227 

Pectoralis  Group 283-241 

General  remark  on  the  pectoral  group 235 

Crossing  of  the  pectoral  elements 235 

Complexity  of  the  pectoral  muscles 235 

Arcus  Bicipitalis,  Bicipital  Arch 245 

Muscles  of  the  Shoulder  and  Arm 247-271 

Structure  of  Muscular  Tissue 272 

Muscular  fibers,  length  and  connection  with  tendons 272 

CHAPTER    YII. 

ABDOMINAL  AND  THORACIC  VISCERA,  MOUTH,  SALIVARY  GLANDS  AND 

NECK. 

Abdominal  Viscera 273-297 

Peritoneum 277,  279 

Diaphragma 277,  311 

Hepar  {liver)  and  Cholecyst  {gall  bladder) 277,  286 

Lobes  of  the  liver  and  its  ducts 286 

Structure  of  the  liver 287 

Stomachus  {stomach) 277,  282 

Small  Intestine,  Duodenum,  Jejunum  and  Ileum,  and  their  Structure 283-284 

Large  Intestine,  Ccecum,  Colon  and  Rectum,  and  their  Structure 285 

j^len  {spleen) , 278,  283 

Omentum  majus  or  Epiploon 278,  280 

Foramen  of  Winslow,  mesenteric  glands 280 

Pancreas  and  its  Ifucts,  with  the  Ampulla  of  Vater 287,  290-293 

Hen  {kidney) 278,  294 

Ureter,  urocystis  (urinary  bladder) 294 

Adrenal  body 295 

Uterus,  Fallopian  Tube  and  Ovary 295-296 

Salivary  Glands 307,  297-303 

Preparation  of  the  ducts 298 


CONTENTS,  XT 

FAOB 

Exposure  of  the  salivary  glands  and  their  ducts 299 

Nerves  associated  with  the  glands  and  ducts 301 

Parotid  Oland 301 

Stenon's  duct 301 

Ac<jessory  parotid  glands 302 

Submaxillary  Gland 302 

Wharton's  duct 302 

Sublingual  Gland 302 

Molar  Gland 302 

Zygomatic  Gland 303 

Structure  of  salivary  glands 303 

Gavum  Oris  {Mouth  Cavity)  and  Pharynx 303 

Structure  of  buccal  walls  and  tongue 304 

Ne^k  {Gollum)  and  Trachea 307 

Structure  of  the  trachea 308 

(Esophagus 308 

Structure  of  the  oesoph.agus 308 

Thorax 308-314 

Pleura  and  septum  mediastinale 309 

Thymus  gland 309 

Lungs 310 

Lobes  and  air  cells  of  the  lungs 310 

Bronchi  and  bronchioli 311 

Structure  of  the  lungs 311 

Diaphragm 311-314 

Central  tendon 31 1 


CHAPTER    VIII. 

VASCULAR   SYSTEM. 

general  Considerations 815 

Blood  Vascular  System 315 

Arteries,  veins  and  capillaries 315 

Lymph  Vascular  System 315-316 

Lymphatic  vessels 316 

Chyle  or  lacteal  vessels 316 

Comparison  of  the  Lymph  and  Blood  Vascular  Systems 316 

Cardia,  Heart 316,  338 

References  to  the  heart  and  remarks 316 

Location  of  the  heart 317 

Pericardium 317 

Form  and  normal  position  of  the  heart 318 

Designation  and  recognition  of  the  regions 318 

Removal  of  the  Heart 319 

Separation  of  the  heart  from  the  lungs 320 

Preservation  of  the  Heart  in  Alcohol. 321 


XVI  CONTENTS, 

PAGE 

Removal  of  the  pericardium  and  blood 321 

Tying  the  vessels,  injection  of  alcohol  and  hardening 321-322 

Table  of  the  Principal  Parts  and  Features  of  the  Heart 322 

List  of  abbreviations  of  cardiac  names ........  325 

Descriptive  list  of  the  parts  of  the  heart,  arranged  alphabetically 325-333 

Dissection  of  the  Heart o 337-338 

Frozen  Sections  of  the  Thorax 338-342 

Blood  Vessels  of  the  Trunk 342-362 

Table  of  the  systemic  and  portal  veins 342-343 

Table  of  the  systemic  vessels  of  the  trunk  and  arm 343-344 

Veins  of  the  Thorax 349-350 

Arteries  of  the  Thorax  and  Arm 350-355 

Abdominal  Blood  Vessels 355-362 

Vena  Portos. 355-356 

Systemic  Abdominal  Veins 356-858 

Aorta  Abdominalis  and  Branches 358-362 

Divisions  of  the  Aorta  Abdominalis 361 

Structure  of  the  Heart  and  Blood  Vessels 362-363 

Thoracic  Ducts  and  Lymphatic  Vessels 363-368 

Vasa  chylifera  s.  lactealia •         364 

Receptacul  um  chyli 364 

Ductus  thoracicus  sinister  et  dexter 364-365 

Lymphatics  of  the  arms,  legs  and  face 367 

If^ection  of  the  Lymphatic  Vessels  and  Glands 367 


CHAPTER    IX. 

NEUROLOGY,  THE  NERVOUS  SYSTEM. 

General  Considerations 369-372 

Nerves,  ganglia,  alba  and  cinerea ' 369 

Primary  Divisions  of  the  Nervous  System 369 

Central  and  Peripheral  Portions  of  the  Mydencephalic  System. 369 

Myelonal  alba  and  cinerea 370 

Motor  and  sensory  nerves  and  nerve  roots 370 

Functions  of  the  Alba  and  Cinerea 371 

Analogies  and  Differences  of  the  Nervous  and  Vascular  Systems 371-372 

Myelencephalic  or  Cerebro-spinal  Nervous  System. 372-394 

Myelon,  Spinal  CoQ'd 372 

Myelonal  or  Spinal  Nerves 373 

Dorsal  and  ventral  (posterior  and  anterior)  primary  divisions  of  the  spinal 

nerves 373 

General  Directions  for  Dissecting  the  Nervous  System 375 

Demonstration  of  the  ventral  primary  division  of  the  myelonal  nerves  of 

the  left  side 376 

Demonstration  of  the  dorsal  primary  division 377 

Exposure  of  the  brain 377 


CONTENTS.  XVU 


PAGE 


Brachial  Plexus  and  the  Principal  Nerves  of  the  Right  Arm  and  Scapular 

Region 379-387 

Nervus  Vagus • 387-394 

Nervus  Sympathicus  (sympathetic  nerve) 394 

Superior  cervical  ganglion 395 

Thyroid  or  middle  cervical  ganglion 395 

Vertebral  or  inferior  cervical  ganglion 395 

NN.  splanchnici 395 

Ganglion  semilunare. 396 

Abdominal  sympatliic 396 

Relations  of  the  Myeltncephalic  and  Sympathie  Nerms 396-398 

Structure  of  Nerwus  Matter 398-399 


CHAPTER    X. 

THE    ENCEPHALON    OR    BRAIN. 

General  Considerations 400 

Importance  and  difficulty  of  the  study 400 

.  Methods  of  studying  the  brain 400 

Consideration  of  the  Brain  of  the  Frog  and  Mendbranchus  as  Simple  Brains. ..  402-403 

Partial  vocabulary  of  encephalic  names 403-404 

Encephalic  Segments 404 

Names  and  synonyms,  tabular  arrangement 405 

Unequal  morphical  value  of  the  segments 406 

Advantages  in  using  segmental  names 406 

Names  of  the  brain  cavities 406 

Objections  to  the  names  commonly  used 406 

Amphibian  Brain — Tabular  Arrangement  of  its  Principal  Parts 409 

Ideal,  Simple  Brain 409 

General  Constitution  of  the  Encephalic  Segments 413 

Metencephalon,    epencephalon,   mesencephalon,    diencephalon,    prosen- 
cephalon, rhinencephalon 413 

Relations  of  the  coeliae 413 

Comparison  of  the  brain  with  a  house 413 

Arachnoidea,  pia,  endyma 413 

Telse  and  plexuses 414 

Foramen  of  Magendie 414,  483 

Complete  circumscription  of  the  brain  cavities 414 

Conarial  tube 415 

Study  of  the  Amphibian  Brain 415 

Obtaining  and  killing  the  animals 415 

Injection  of  the  brain 416 

Exposure  of  frog's  brain 416 

Exposure  of  the  brain  of  Menobranchus 417 

Preservation  of  amphibian  brain \ 418 

Labeling 418 

General  Inspection  of  the  Amphibian  Brain 418-430 

Dissection  of  the  amphibian  brain 430-433 


XVlll  '  CONTENTS. 

PAGE 

Removal  of  the  Brain  of  the  Cat  with  Cranial  Nerves 423-428 

Removal  of  the  dura 428 

Transferring  the  brain  to  alcohol,  weighing  and  removing  the  pia 429 

Other  Methods  of  Removing  the  Brain 431-433 

By  nipping  away  the  calva,  and  application  to  the  removal  of  the  brain 

of  infants 431-432 

Hemisection  of  the  head  with  a  saw 432 

Mesal  and  lateral  hemisection , 433 

Hardening  a  hemisected  brain 435 

Zinc  Chlorid  Method  of  Hardening  Brains 435 

Injection  of  the  CmlicB  with  Alcohol  and  with  Plaster 435 

Injection  of  the  Plexuses ....    436 

Macroscopic  Vocabulary  of  the  Brain 436-438 

Table  of  encephalic  names 448-449 

JEncephalic  Segments  in  the  Cat 439-461 

Differences  between  the  brains  of  cat  and  frog 439 

Hemisection  of  the  brain 444 

.  Inspection  of  the  mesal  aspect 446 

Segmental  arrangement  of  the  names  of  the  brain 446 

Examination  of  the  encephalic  segments 450-454 

Aula  and  porta  or  foramen  of  Monro 454 

Demonstration  of  the  Frocoelia,  Phinocodia  and  Porta  (lateral  and  olfactory 

ventricles  and  foramen  of  Monro) 454-455 

Eypocampa — Exposure,  etc 455-456 

Striatum — Mesal  Aspect 456 

PrcBcommissura — Exposure 455 

Relations  of  the  plexuses  to  the  membranous  walls  of  the  porta,  diacoelia 

and  medicornu 459 

Explanation  of  the  Plates  of  the  Brain 461-471 

List  of  Encephalic  Names  with  Synonyms  and  References,  alphabetically 

arranged 471-491 

Comments  upon  Figures  of  Feline  Brains 491-493 

The  Cerebrum  and  its  Fissures 493-500 

Form  of  the  cerebrum 493 

Fissures  of  the  cerebellum 494 

Table  of  Abridged  Synonymy  of  the  Cerebral  Fissures 496 

The  three  problems  connected  with  the  study  of  the  fissures 497 

Formation  of  the  fissures 497 

Structural  Relations  of  Certain  Fissures,  icith  a  List 497 

F.  callosalis,  callosal  fissure 497 

F.  fimbria 497 

F,  hypocampse,  hypocampal  fissure 497 

'  F.  Sylviana 498 

F.  ansata 4S8 

F.  anterior 498 

F.  cruciata,  Crucial  or  Cruciate  Fissure 498 

Constant  and  peculiar  characters 498 

Variable  characters — Names  and  synonyms 498-500 

Homology,  with  views  of  various  authors 502 


CONTENTS.  XIX 

PAOB 

Designation  of  the  Gyrl 500 

Table  showing  three  ways  of  enumerating  the  arched  gyri 501 

The  angular  gyrus 501 

The  Fissural  Pattern— Constant  Characters 501 

List  of  constant  fissures 501 

Variable  characters  of  the  fissural  pattern 503 

List  of  inconstant  fissures 502 

Homology  of  Human  and  Feline  Fissures,  with  Difficulties 502 

Promising  lines  of  inquiry 503 


CHAPTER    XI. 

THE  CRANIAL   NERVES  AND  THE  ORGANS  OP  SENSE. 

Cranial  Nerves — General  Considerations 504 

Comparison  of  cranial  and  myelonal  nerves 504 

Table  of  synonyms  of  cranial  nerves 505 

Numerical  designation  of  the  cranial  nerves  by  Willis  and  Sommering. ,  505 

Physiological  arrangement  of  the  cranial  nerves 505-506 

Sensory  nerves,  special  and  general 506 

Special  Consideration  of  the  Twelve  Cranial  Nerves 507-510 

Table  of  the  Cranial  Nerms,  giving  Fetal  Origins,  Foramina  of  Exit,  Distribu- 
tion and  Function 510 

Directions  for  the  Demonstration  of  the  Cranial  Nerves 511 

Organs  of  Sense 511-533 

General  Considerations 511 

Skin,  tongue,  nose,  eye,  ear,  general  sensibility 511 

Cutis,  the  Skin 512 

Structure  and  function  of  its  various  parts 512 

Appendages  of  the  skin — Hair,  claws,  sweat  and  sebaceous  glands 512 

Tactile  hairs 512 

Lingua,  the  Tongue— Uses,  papillae,  nerves 512-513 

Nasus,  the  Nose — Lining  membrane,  sensibility  of  its  various  parts 513 

Nares,  praenares  and  postnares 513 

Oculus,  the  Eye 514-526 

Appendages  of  the  Eye 514-516 

Palpebr^  or  lids 514 

Conjunctiva 514 

Canthi  of  the  lids  514 

Meibomian  glands 514 

Membran£^  nictitans — Attachment  and  office 515 

Lachrymal  apparatus 515-520 

Muscles  of  the  Eye 51 6-520 

Origins  of  the  muscles  of  the  eye 519 

Action  of  the  muscles  of  the  eye 519 

Nervous  supply  of  the  muscles 520 

Globus  Oculi,  Eyeball 520-526 

How  to  obtain  the  eyeball  of  a  cat,  ox  or  sheep 520 

Form  and  parts  of  the  eyeball 520 


XX  CONTENTS, 

PAGE 

Iris  and  pupil 520 

Images  formed  by  the  eye 520 

Tunics  or  coats  of  tlie  eye 521 

Preservation  of  an  eye  in  alcohol  for  the  coats 521 

Sclerotica  and  cornea 521 

Choroidea,  plicae  ciliares 521-522 

Retina,  ora  serrata  and  pars  ciliaris  retinae 522 

Tapetum 522 

Aqueous  humor  and  aqueous  chambers 522 

Corpus  vitreum  or  vitreous  humor 522 

Lens,  ligament  and  capsule 522-523 

Organum  Auditus,  Auris,  Ear 526-533 

External  Ear 526 

Tympanum,  Middle  Ear 527 

Membrana  tympani 527 

Canalis  Eustachiana 528 

Malleus  and  tensor  tympani  muscle 528 

Incus  and  Os  lenticulare 528 

Stapes  and  stapedius  muscle 529 

Labyrinthus,  Internal  Ear 529 

Vestibulum 529 

Fenestra  ovalis  and  fenestra  rotunda 529 

Cochlea 529 

Scala  vestibuli  and  scala  tympani 529 

.    Modiolus  and  lamina  spiralis 529 

Canales  semicirculares 530 

APPENDIX 534-537 

BIBLIOGRAPHY 538-553 

IXDEX 554-575 


LIST  OF  ILLUSTRATIONS. 


In  respect  to  twenty-six  figures  we  are  indebted  to  the  persons  named  in  parenthesis, 
either  for  the  idea  of  a  figure  or  for  the  use  of  an  electrotype.  Of  the  original  figures,  the 
larger  number  were  drawn  by  E.  C.  Cleaves,  Professor  of  Free-hand  Drawing  in  Cornell 
University.  The  four  plates  of  the  brain  were  drawn  and  lithographed  by  Miss  G.  D. 
Clements,  who  also  drew  Fig.  81-82.  Fig.  11-12,  14-19,  were  drawn  by  Miss  I.  M. 
Curtis;  Fig.  126-128,  by  Mrs.  S.  S.  Phelps  Gage;  and  Fig.  92,  110-112,  121-123,  by  the 
senior  author. 

In  preparing  the  drawings  for  the  original  figures,  the  specimens — now  preserved  in 
the  museum  of  Cornell  University — were  photographed  with  a  vertical  camera,  as  sug- 
gested by  the  junior  author  (6).  The  outlines  of  the  drawings  were  traced  directly  from 
these  photographs ;  hence  the  relative  size  and  position  of  parts  are  accurately  represented. 
Finally  the  drawings  were  photo-engraved. 


nOURE  PAGE 

1. — Paper  Meter  Yard  (American  Metric  Bureau) 6 

2-4. — Diagrams  of  Three  Aspects  of  a  Vertebrate,  exhibiting  the  most  general 

features 30 

5. — Diagrams  of  the  Three  Body  Planes,  with  the  various  lines  of  direction 34 

6. — Diagram  of  the  Dorsal  Aspect  of  the  Cat,  with  the  limbs  in  the  normal  position.  38 
7. — Diagram  of  an  Ideal  Transection  of  the  Thorax  of  the  Cat,  with  the  arms  in  an 
approximately  normal  position,  and  showing  the  location  of  the  principal 

viscera 43 

8. — Japanned  Tray  for  Catalogue  Slips  (Readers'  and  Writers'  Economy  Co.) 50 

9. — Pigeon-hole  Case  (Readers'  and  Writers'  Economy  Co.) 51 

10.— Stubs's  Nippers  (Codman  and  Shurtleff) 62 

11-12. — Nippers  and  Fine  Scissors 63 

13. — Small  Compressor  (Geo.  Frost  &  Co.)  ....   65 

14. — Blunt-pointed  Scalpel 66 

15. — Syringotome 66 

16. — Arthrotome 66 

17.— Tracer 66 

18. — Coarse  Forceps 66 

19.— Flexible  Blow-pipe , 66 

20.— Fine  Curved  Forceps 66 


XXll  LIST  OF  ILLUSTRATIONS. 

riGURE  PAGE 

21. — Back-saw  (Goodnow  and  Wiglitman) 68 

22.— Large  Scalpel  (Codman  and  Shurtleff) 69 

23.— Medium  Scalpel  (Codman  and  Shurtleflf) 69 

24. — Charriere  Scalpel  (Codman  and  Shurtleff) 69 

25. — Coarse  Scissors,  curved  flatwise  (Codman  and  Shurtleff) 70 

26.— Tripod  Magnifier  (Smith  and  Beck) 72 

27. — Wetting  Bottle  for  15  per  cent.  Glycerin 72 

28. — Honing  and  Stropping  Knives 76 

29.— Anaesthetic  Box 81 

30. — The  Skeleton  seen  from  the  Left  (Straus -Durckheim,  A) 88 

31.— Covered  Glass  Box  (Whitall,  Tatum  &  Co.) 126 

32. — Wide-mouthed  Specimen  Jars  with  Covers  (Whitall,  Tatum  &  Co.) 127 

33.— Welted  Vial  for  the  Brain  or  Heart 128 

34— Bottle  Brush 129 

35.— White  Metal  Syringe  with  top  unscrewed  and  piston  removed 138 

36.— Canulae 138 

37.— Brass  Syringe  (Codman  and  Shurtleff) 139 

38. — Small  Brass   Syringe  with  removable   Stop-cock  and  Canulae  for  Fine    Injec- 
tions (Codman  and  Shurtleff) 139 

39.— Femoral  Vessels  exposed  for  Injection 142 

40. — Incisions  and  Preparations  for  Ligating 144 

41. — Double  Ligature,  Surgeon's  and  Square  Knot 144 

42. — Inserting  and  Securing  Canulae 145 

43. — Ental  Aspect  of  an  Adult  Left  Scapula 154 

44. — Ectal  Aspect  of  an  Adult  Left  Scapula 155 

45. — The  Glenoid  End  of  an  Adult  Right  Scapula  and  the  Proximal  End  of  an  Adult 

Right  Humerus 156 

46.— Ventral  Aspect  of  an  Adult  Right  Humerus 158 

47. — Dorsal  Aspect  of  the  Carpal  Region  of  a  Young  Lion  and  of  two  Young  Dogs 

(Wilder,  9) 101 

48.— Right  and  Left  Claviculae  of  an  Old  Cat 162 

49. — Ventral  Aspect  of  an  Adult  Sternum  163 

50. — Caudal  View  of  the  Seventh  Pair  of  Ribs 166 

51. — Ventral  View  of  the  Cat's  Pelvis  with  adjacent  Vertebrae  (modified  from  Straus- 

Durckheim,  A) 168 

52. — Ventral  Aspect  of  the  Cervical  and  two  Thoracic  Vertebrae  (modified  from  Straus- 

Durckheim,  A) 172 

53.— Caudal  View  of  the  Fourth  Cervical  Vertebra 173 

54. — Caudal  View  of  the  Seventh  Thoracic  Vertebra 173 

55. — Caudal  View  of  the  Fourth  Lumbar  Vertebra 173 

56.— Dorsal  View  of  the  Skull 180 

57. — Ventral  Aspect  or  Base  of  the  Skull  (modified  from  Straus-Durckheim,  A) 182 

.58. — Ventro-lateral  View  of  the  Left  Bulla  tympanica  and  Adjacent  Parts 185 

59.— Hemisection  of  the  Skull,  Right  Side 186 

60. — Dorso-caudal  View  of  the  Lamina  Cribrosa  and  the  Sinus  Frontalis 188 

61. — Lateral  View  of  the  Left  Mandibular  Ramus 188 

62. — Dorsal  View  of  the  Mandible  (modified  from  Straus-Durckheim,  A) 189 

63.— The  Scalpel  Held  as  a  Pen  (Bernard,  A) 199 

64.— The  Scalpel  Held  as  a  Carving-knife  (Bernard,  A). 200 

65.— The  Scalpel  Held  as  a  Violin-Bow  (Bernard,  A) 200 


LIST    OF   ILLUSTRATIONS.  Xxiii 

FIGT7RE  PAGB 

66.— The  Ectal  Skeletal  Muscles  of  the  Neck  and  Shoulder 211 

67. — The  Second  Layer  of  Skeletal  Muscles  of  the  Neck  and  Shoulder 218 

63-71. — Views  of  the  Four  Aspects  of  the  Humerus  with  Areas  of  Muscular  Attach- 
ment    228 

72. — The  Pectoralis  Group  of  Muscles 234 

73. — Ental  Aspect  of  Left  Shoulder  Muscles  and  Ectal  Aspect  of  the  Serratus  Mag- 
nus and  Levator  Anguli  Scapulae  Muscles 246 

74. — The  Cephalic  Aspect  of  the  Left  Arm  with  the  Ectal  Muscles  of  the  Scapula.  254 
75.— The  Muscles  upon  the  Ental  Aspect  of  the  Scapula  and  the  Caudal  Aspect  of 

the  Brachium  and  Antebrachium 4 263 

76. — Lines  of  Incision  for  exposing  the  Thoracic  and  Abdominal  Viscera 274 

77. — General  View  of  the  Viscera 276 

78. — Diagram  showing  the  Relations  of  the  Abdominal  Organs  and  the  Perito- 
neum     279 

79. — Stomach  and  Duodenum,  Ventral  View 281 

80. — Csecum  and  Ileo-caecal  Valve,  Ventral  View 284 

81. — Ventral  View  of  the  Pancreas  and  its  Parts  (Gage,  3) 288 

82. — Cholecystis  and  Pancreatic  Reservoir  and  their  Relation  with  the  Duodenum 

(Gage,  3) 289 

83. — Ventral  View  of  the  Human  Pancreatic  Ducts  (Bernard) 290 

84. — Longitudinal  Section  of  the  Ampulla  of  Vater,  showing  the  Entrance  of  the 
Ductus  Choledochus  and  the  Duct  of  Wirsung  (Gage,  3) ;  the  same  in  man 

(Bernard,  17)  291 

85. — Dorso-ventral  Section  of  the  Right  Kidney,  Caudal  View 293 

86. — Longitudinal  Dextro-sinistral  Section  of  the  Right  Kidney,  Ventral  View 293 

87.— Salivary  Glands  of  the  Left  Side 300 

88. — Hemisection  of  the  Head 305 

89. — Lungs  and  Trachea 310 

90. — Caudal  View  of  the  Diaphragm  with  the  Structures  that  traverse  it 313 

91. — The  Dorsal  Aspect  of  the  Heart  with  the  Central  Portions  of  the  Larger  Ves- 
sels   317 

92. — Diagram  of  the  Cardiac  Cavities,  Dorsal  Aspect 323 

93. — Dorsal  Part  of  the  Heart  seen  from  the  Ventral  Aspect 333 

94. — Longitudinal  Segment  of  the  Heart,  showing  the  Right  Sinus  of  Valsalva  and 

Cardiac  Artery 333 

95. — Transection  of  the  Auricles,  Caudal  Aspect 334 

96. — Transection  of  the  Auricles,  Cephalic  Aspect 335 

97. — Transection  of  the  Ventricles,  Caudal  Aspect 336 

98. — Transection  of  the  Ventricles,  Cephalic  Aspect 836 

99. — Frozen  Transection  of  the  Thorax,  Caudal  Aspect 340 

100. — Frozen  Transection  of  the  Thorax,  Cephalic  Aspect 341 

101. — General  View  of  the  Blood  Vessels,  and  Diagrams  of  the  Beginnings  of  the 

Postcava  and  Termination  of  the  Aorta 345 

102. — The  Aorta  with  its  Main  Branches  in  the  Thorax  and  Right  Arm,  also  Origin 

of  the  Carotid  Arteries  :  Veins  with  Valves  (Quain,  A) 347 

103. — The  Left  Thoracic  Duct,  Sinistral  View,  and  Termination  of  the  Thoracic 

Duct 366 

104. — Dorsal  Aspect  of  the  Brain  and  of  Part  of  the  Myelon  with  its  Nerves 374 

105. — Ventral  Aspect  of  the  Right  Brachial  Plexus  and  its  Nerves 378 

106. — Diagram  of  the  Right  Brachial  Plexus,  Ventral  View 381 


XXIV  LIST    OF  ILLUSTRATIONS. 

PIGUEB  PAQB 

107.— The  Vagus  and  Sympathic  Nerves  and  a  Diagram  of  the  Sacral  Part  of  the 

Sympathic 393 

108. — The  Recurrent  Laryngeal  Nerves,  Ventral  View  (Stowell,  1) 394 

109. — Transection  of  the  Thorax,  showing  the  Origin  of  a  Pair  of  Spinal  Nerves  and 

the  Relations  of  the  Sympathic  and  Cerebro- Spinal  Systems,  Cephalic  View.  397 
110. — Longitudinal  Dextro-Sinistral  Section  of  an  Ideal,  Simple  Brain,  showing  the 
Relations  of  the  Cavities,  the  Sequence  of  the  Encephalic  Segments,  and  the 

Relations  of  the  Coelise , 408 

111.— Mesal  Aspect  of  the  Right  Half  of  an  Ideal,  Simple  Brain,  showing  the  Con- 
tour and  Constitution  of  the  Coelian  Floors  and  Roofs 408 

112. — Transection  of  Several  Segments  of  the  Ideal  Brain,  showing  the  Coeliae  and 

their  Parietes 408 

113.— Ventral  Exposure  of  the  Coeliae 440 

114. — Dorsal  Aspect  of  the  Mesencephalon,  with  Adjacent  Parts 441 

115. — Dorsal  Aspect  of  the  Callosum  after  Partial  Removal  of  the  Hemispheres 443 

116.— Diagram  of  the  Base  of  the  Brain 443 

117. — Diagram  of  the  Mesal  Aspect  of  the  Left  Hemiencephalon 446-447 

118.— Diagram  of  the  Area  Cruralis  of  the  Brain 447 

119. — Plaster  Casts  of  the  Medicornua  Inverted 458 

120.— Plaster  Casts  of  the  Diacoelia  (Dorsal  Portion),  Aula,  and  Right  Porta  and  Prse- 

cornu  of  the  Sheep,  inverted   . .    458 

121. — Diagram  of  a  Section  of  the  Left  Medicomu 458 

133 —Diagram  of  a  Transection  of  the  Brain  through  the  Diacoelia 458 

133.— Diagram  of  a  Transection  of  the  Porta  (Foramen  of  Monro) 458 

134. — Cerebral  Fissures,  Lateral  Aspect 494 

135. — Cerebral  Fissures,  Mesal  Aspect 494 

136.— Section  of  the  Eye,  in  situ 534 

127.— Diagram  of  the  Ear 533 

128.— Transection  of  a  Coil  of  the  Cochlea  (Quain,  A.) 533 

139.— Dropping-bottle  Oiler 535 

130.— Method  of  holding  a  Frog  for  Pithing 536 


FOUK    PLATES    OF    THE    BRAIN.     (Wilder,   14.) 

For  the  use  of  these  plates  we  are  indebted  to  the  American  Philosophical  Society  of 

Philadelphia. 

^  PLATE  I. 

1. — Dorsal  Aspect  of  the  Brain. 

3.— Sinistral  Aspect  of  the  Brain. 

PLATE  II. 

3. — ^Basis  Encephali,  or  Ventral  Aspect  of  the  Brain. 
4— Mesal  Surface  of  the  Right  Hemiencephalon. 

PLATE  III. 
5.— Cephalic  Aspect  of  the  Prosencephalon. 

6._Caudal  Aspect  of  the  Prosencephalon,  with  part  of  the  Diencephalon. 
7. — Dorsal  Aspect  of  the  Diencephalon  and  Mesencephalon. 


LIST    OF   ILLUSTRATIONS,  XXV 

FIGURE 

8.— Caudal  Aspect  of  the  Mesencephalon,  with  parts  of  the  adjoining  regions. 

9. — Sinistral  Aspect  of  the  Mesencephalon  and  Diencephalon. 
10. — Dorsal  Aspect  of  the  Diencephalon,  including  the  Diatela. 

11. Area  Cruralis,  with  part  of  the  Pons  and  of  the  Area  Praechiasmatica. 

12. — Dorsal  Aspect  of  the  Metencephalon. 

13. Part  of  an  Oblique  Transection  of  the  Prosencephalon  and  Diencephalon  to  sho>» 

the  Form  and  Position  of  the  Crista  Fornicis. 

PLATE  IV. 

14. — ^Ventro-caudal  View  of  the  Fornix,  with  the  adjacent  parts. 

15. — Dorsal  Aspect  of  the  Proccelia. 

16. — Rhinocoelia  and  Procoelia. 

17. — Mesal  Aspect  of  the  Right  Hemisphere,  with  the  Lobus  Olfactoriua* 

18. — Right  Procoelia  seen  from  the  Right  or  Ectal  Side. 

19. — Left  Prsecornu  and  Porta  exposed  from  the  Left  or  Ectal  Side. 

20. — Transection  of  the  Fornix  with  the  Crista. 


LIST  OF  TABLES  AND  ALPHABETICAL  LISTS. 


Table  of  some  equivalent  Temperatures,  according  to  the  Centi- 
grade and  Fahrenheit  scales 4 

Table  of  the  Metric  Measures 5 

Table  of  Metric  Equivalents 7 

Table  of  Zoological  Classification 9 

Table  of  the  Principal  Divisions  of  the  body 39 

Table  illustrating  the  Subdivision  of  Notes 49 

List  of  Anatomical  Instruments  and  Materials 59-62 

Table  of  the  Specific  Gravities  of  different  Percentages  of  Alcohol..  113 

Table  of  the  Ratios  of  Alcohol  and  Water  to  produce  a  given 

Percentage 116 

Composition  of  Wickersheimer's  Liquid 124 

Table  of  the  Bones  of  the  Skull,  showing  the  Synonyms  and  An- 

thropotoraical  Equivalents 174-176 

Table  of  Articulations  of  the  Bones  of  the  Skull 176-179 

Table  of  the  Cranial  Foramina  and  of  the  Structures  which  traverse 

them 190 

Table  of  the  Synonyms  of  forty  Muscles 207 

Table  of  the  Principal  Parts  and  Features  of  the  Heart 322 

Table  of  the  Systemic  veins  of  the  Trunk  and  of  the  Portal  Veins..  342 

Table  of  the  Systemic  Arteries  of  the  Trunk  and  Arm 343 

List  of  the  Principal  Parts  of  the  Amphibian  Brain,  with  their 

more  common  Synonyms 403 

Table  of  the  Names  and  Synonyms  of  the  Encephalic  Segments.. .  405 

Tabular  arrangement  of  the  Principal  Parts   of  the  Amphibian 

Brain 409 

List  of  Abbreviations  of  general  Encephalic  names 436 

List  of  Abbreviations  of  special  Encephalic  names 436-438 

Tabular  arrangement  of  the    Names  of  the  Parts  of  the  brain 

according  to  the  Segments 448,  449 

List  of  Synonyms  and  References  for  the  Encephalic  parts 471-491 

List  of  writers  who  have  figured  the  Feline  Brain 491-493 

Abridged  Synonymy  of  the  Cerebral  Fissures 496 

List  of  writers  who  have  mentioned  the  Cruciate  Fissure 499,  500 

Table  showing  four  Methods  of  enumerating  the  " arched  gyri "...  501 

Table  of  the  Synonyms  of  the  Cranial  Nerves 505 

Provisional  Physiological  Arrangement  of  the  Cranial  Nerves 506 

Table  of  the  Origin,  Distribution,  etc.,  of  the  Cranial  Nerves 510 


INTRODUCTIOISr. 


§  1.    There  are  five  matters  of  general  application  : — 

1.  The  reference  to  other  Publications. 

2.  The  designation  of  Weights,  Measures  and  Temperatures. 

3.  The  names  of  Animals,  and  of  the  Groups  to  which  they  belong. 

4.  The  designation  of  the  Parts  of  animals,  and  the  indication  of  their 
Position  and  Direction. 

5.  The  making  and  arrangement  of  Notes. 

The  treatment  of  these  matters  in  the  present  work  may  be  characterized 
briefly  as  follows  : — 

1.  The  citations  are  numerous  and  explicit. 

2.  Only  decirnal  systems  are  employed, — the  Centigrade  scale  and  the 
Metric  system. 

3.  The  classification  adopted  is  in  accordance  with  generally  accepted 
views. 

4.  The  terminology  is  intended  to  have  the  following  features  :  general 
application  to  all  Vertebrates  ;  intelligibility  to  all  nations  ;  accuracy ; 
brevity  ;  simplicity  ;  consistency  ;  uniformity  of  abbreviation. 

5.  What  may  be  called  the  slip-system  of  notes  is  recommended. 


L— REFERENCES  TO   PUBLICATIONS. 

§  2.  We  have  thought  it  best  to  m.ake  somewhat  full  references  to  other 
Manuals  and  Compendiums,  and  to  the  Works  and  Papers  of  original 
observers.     Our  reasons  are  : — 

1.  This  work  is  designed  to  be  used  not  only  by  the  general  student,  but 
also,  as  an  elementary  introduction,  by  those  who  are  themselves  to  become 
investigators.  In  our  opinion,  these  latter  cannot  too  soon  become  familiar 
with  the  sources  of  original  information,  and  with  the  views  of  the  present 
and  past  leaders  in  scientific  progress. 


2  INTRODUCTION. 

2.  Upon  some  points,  especially  that  of  Terminology,  we  feel  that  the 
acceptance  of  our  ideas  will  be  more  ready  and  complete  if  it  be  shown  that 
they  are  shared  by  other  and  more  widely  known  writers. 

3.  While  we  are  responsible  for  whatever  may  prove  to  be  erroneous,  we 
are  very  loth  to  run  the  risk  of  receiving,  even  from  beginners,  credit  for 
having  first  made  an  observation  or  an  experiment,  or  first  devised  an 
instrument  or  a  mode  of  manipulation,  the  honor  of  which  belongs  properly 
to  others. 

4.  On  the  other  hand,  since  our  statements  as  to  the  structure  of  the  cat 
do  not  always  accord  with  those  of  other  writers,  our  own  papers  are  fre- 
quently referred  to  in  evidence  that  those  statements  have  already  been 
submitted  to  competent  scientific  tribunals. 

§  3.  References. — In  the  text,  the  capital  letter  or  Arabic  numeral 
directly  following  an  author's  name  indicates  the  place  of  the  work  or  paper 
upon  the  List.     This  letter  or  numeral  is  in  black  letter. 

The  second  Arabic  numeral  designates  the  number  of  the  page.  When 
the  introductory  portions  of  a  book  are  separately  paged  the  Eoman  numeral 
designating  the  page  is  preceded  by  the  letter  p. 

When  a  work  consists  of  two  or  more  volumes,  the  number  of  the  volume 
in  question  is  indicated  by  a  Eoman  numeral  placed  between  the  two  Arabic 
numerals. 

When  two  or  more  works  or  papers  are  referred  to  after  the  name  of  the 
same  author,  their  letters  or  numbers  are  separated  by  a  semicolon. 

The  numbers  of  two  or  more  pages  or  volumes  are  separated  by  commas, 
or  by  short  dashes  when  the  passages  in  question  extend  over  several  pages. 

For  example  :  Rolleston,  A,  10,  refers  to  the  tenth  page  in  the  body  of 
the  work  of  the  '^^  Forms  of  Animal  Life."  Rolleston,  A,  p.  x,  refers  to  the 
tenth  page  of  the  Introductory  portion  of  the  same  work.  Agassiz,  A,  iv, 
10,  refers  to  the  tenth  page  of  the  fourth  volume  of  the  "  Contributions  to 
the  Nat.  Hist,  of  the  U.  S."  Wyman,  34,  10,  refers  to  the  tenth  page  of  the 
'^Anatomy  of  the  Nervous  System  of  Rana  pipiensy^  which  was  published 
among  the  '^Smithsonian  Contributions  to  Knowledge,"  and  is  hence 
regarded  as  a  paper. 

On  account  of  the  large  number  of  citations,  we  have  usually  omitted  the  words 
wlume  and  page  and  their  abbreviations.  This  is  regarded  as  permissible  by  Bigelow  ; 
A,  49. 

The  following  is  the  mode  of  reference  : — 

Near  the  end  of  the  book  is  a  ^'List  of  Publications  referred  to."  In 
that  list,  the  names  of  Authors  occur  in  alphabetical  order. 

Under  each  name,  the  titles  are  in  two  groups,  including  respectively 
Separate  Books,  and  Papers  published  in  Journals  or  by  Scientific  Societies. 


DESIGNATION    OF    TEMPERATURES.  3 

The  works  are  designated  by  letters,  the  papers  by  Arabic  numerals.  The 
former  have  no  definite  order,  and  no  significance  is  to  be  attached  to  their 
sequence. 

The  papers  are  numbered,  so  far  as  possible,  as  in  the  "  Catalogue  of 
Scientific  Papers  "  published  by  the  Koyal  Society  of  London  (A),  where 
the  order  is  intended  to  be  chronological.  The  eight  volumes  of  that 
Catalogue  already  published  include  the  papers  which  have  appeared  between 
the  years  1800  and  1873.  On  our  list,  the  papers  issued  since  the  latter 
date  are  assigned  provisional  numbers  in  italics. 

In  the  case  of  papers,  as  in  the  Royal  Society  Catalogue  ^^  when  possible, 
both  the  volume  and  the  year  have  been  given.  With  Transactions  of 
Societies  the  year  to  which  the  volume  belongs,  and  not  the  year  of 
publication,  has  been  given.  A  date  enclosed  in  brackets  marks  the  time 
when  a  paper  was  read,  which  occasionally  precedes  by  some  years  the  date 
of  the  volume  in  which  it  is  printed." 

We  shall  be  thankful  for  corrections  or  suggestions  which  may  make  the  Bibliography 
extensive  and  accurate. 


II.— THE  DECIMAL  SYSTEMS. 

§  4.     The  two  decimal  systems  used  in  scientific  work  are : — 

1.  The  measurement  of  Temperature  upon  the  centigrade  scale  by  the 
bhermometer  of  Celsius. 

2.  The  metric  system  of  Weights  and  Measures. 

THE    CENTIGRADE   THERMOMETER. 

§  5.  Upon  this,  the  Thermometer  of  Celsius,  0  (zero)  represents  the 
;emperature  of  melting  ice.  The  point  attained  by  the  column  of  Mercury 
it  the  temperature  of  boiling  water  is  marked  100  {one  hundred). 

Between  these  two  points,  the  scale  is  divided  into  100  degrees  in  groups 
'^f  10  each. 

According  to  this  scale,  the  average  temperature  of  the  human  body  is 
)etween  37  and  38,  and  that  of  the  comfortable  atmosphere  of  a  sitting- 
•oom  in  winter  about  20. 

Fahrenheit's  Thermometer. — Upon  this,  the  melting  point  of  ice  is 
narked  33,  and  the  boiling  point  of  water  212. 

§  6.  Comparison  and  Reduction  of  the  two  Scales. — Since  the 
3^ahrenheit  thermometer  is  largely  used  in  English-speaking  countries,  the 
bllowing  Table  and  Formulae  may  be  useful.  The  former  is  taken  from 
Idttre  et  Robin,  (A,  1594,  Article  ^^Thermometre") ;  the  latter  from 
Dunglison,  (A,  488,  Article  "Heat"). 


4  INTRODUCTION, 

TABLE 

OF  SOME  EQUIVALENT    TEMPERATURES  ACCORDING    TO    THE    THERMOMETRIC 
SCALES  OF  CELSIUS   (CENTIGRADE)    AND  FAHRENHEIT. 


c. 

F. 

0 

32 

10 

50 

20 

68 

30 

86 

35 

95 

[37.3  +  ] 

\m 

40 

104 

50 

122 

60 

140 

70 

158 

80 

176 

90 

194 

100 

212 

Formulas  for  the  reduction  of  the  Fahrenheit  to  the  centigrade  scale, 
and  vice  verm. 

To  reduce  F.  to  C,  subtract  32,  multiply  by  5,  and  diyide  by  9.  To 
reduce  C.  to  F.,  multiply  by  9,  divide  by  5,  and  add  32. 

1  C.  equals  1.8  F.     1  F.  equals  .555  C. 


THE   METRIC   SYSTEM. 

§  7.     Definition. — The  Metric  System  of  Weights  and  Measures  is  baseAj 
upon  the  meter  as  a  standard  of  length.  ^ 

The  Meter. — This,  the  unit  of  length,  equals,  approximately,  one  ten- 
millionth  part  of  the  quadrant  of  the  meridian  circle  which  passes  throtigh 
Dunkirk  and  Barcelona ;  it  is  thus  about  one  forty-millionth  part  of  the 
earth's  circumference  as  measured  upon  that  line. 

In  common  English  measure,  the  meter  is  39.37079  inches,  or  about 
3  feet  3  inches  and  a  third,  or  about  three  and  one  third  inches  more  than 
a  yard. 

The  Liter. — This  is  the  unit  of  capacity.  It  represents  the  space 
occupied  by  a  cube  whose  edge  is  one  tenth  of  a  meter. 

The  liter  corresponds  nearly  to  our  quart ;  more  accurately,  it  is  1.056 
common  quart ;  0.880  imperial  quart ;  0. 907  dry  quart. 

The  Gram. — This  is  the  unit  of  tueight.  It  represents  the  weight  of  a 
cube  of  distilled  water  whose  edge  is  one  hundredth  of  a  meter,  and  at  a 
temperature  of  4°  0. 


THE    METRIC    SYSTEM,  5 

The  gram  is  15.432  Troy  grains;  or  0.564  avoirdupois  drams ;  or  0.035 
avoirdupois  ounces.  The  U.  S.  nickel  five-cent  piece  weighs  five  grams,  and 
is,  moreover,  one  fiftieth  of  a  meter  (2  cm.)  in  diameter. 

The  other  measures  of  length,  capacity,  and  weight  are  decimal  divisions 
or  multiples  of  the  meter,  the  liter,  and  the  gram,  and  their  names  are  so 
formed  as  to  indicate  their  value  in  each  case. 

§  8.  As  compared  with  the  English  or  any  other  system  of  weights  and 
measures,  the  Metric  System  has  the  following  desirable  features : — 

1.  It  has  a  single  basis,  and  involves  fewer  separate  terms ;  hence  it  is 
more  easily  learned. 

2.  It  is  decimal ;  hence  it  is  more  easily  used. 

3.  It  is  already  2)ractically  international,  and  largely,  if  not  chiefly, 
employed  in  the  best  kinds  of  scientific  work. 

We  do  not  feel  called  upon  for  a  g^eneral  discussion  of  the  merits  of  the  Metric 
System.  Its  origin,  nature,  and  advantages  have  been  admirably  set  forth  in  the  works  of 
F.  A.  P.  Barnard,  J.  Pickering  Putnam,  Persifor  Frazer,  etc,  and  are  periodically  urged 
by  able  writers  in  various  Journals,  medical,  scientific,  and  sociological.  Philosophical 
treatises  upon  the  general  subject  are  published  by  "  The  American  Metrological  Society," 
and  "The  American  Metric  Bureau "  prints  a '*  Bulletin  "  (A).  The  final  issue  of  "The 
Harvard  Register"  contains  a  compact  and  at  the  same  time  comprehensive  plea  " In 
favor  of  the  Metric  System,"  the  force  of  which  is  rather  increased  than  diminished  by  the 
article  just  following  it  upon  the  opposite  side. 

Practically,  out  of  the  twenty-three  or  four  names  for  measures  of  length,  capacity, 
and  weight  which  may  be  employed,  only  about  one-third  are  in  common  use  by  scientific 
men.  These  are,  the  meter ^  liter,  and  gram;  the  ceniiraeter  and  millimeter,  being 
respectively  the  hundredth  and  the  thousandth  of  the  meter ;  the  milligram,  the  thou- 
sandth of  the  gram  ;  the  kilogram  or  thousand  grams ;  and  the  cnJbic  centimeter,  which  is 
the  same  as  milliliter,  the  thousandth  part  of  the  liter. 

§  9.  The  following  Table  includes  all  the  regular  metric  denominations, 
but  only  the  eight  or  nine  whose  names  are  printed  in  capitals  are  in 
general  use. 

TABLE   OF  THE  METRIC   MEASURES. 


DIVISIONS. 
UNITS. 
MULTIPLES.    \ 


LENGTH. 


MILLIMETER. 

CENTIMETER. 

Decimeter. 

METER. 

Dekameter. 

Hektometer. 

KILOMETER. 

Myriometer, 


WEIGHT. 


MILLIGRAM. 

Centigram. 

Decigram. 

GRAM. 

Dekagram. 

Hektogram. 

KILOGRAM. 

Myriogram. 


CAPACITY. 


Milliliter.   Thousandths. 
(CUBIC  CENTIMETER.) 
Centiliter.    Hundredths. 
Deciliter.     Tenths. 
LITER. 

Dekaliter.     Tens. 
Hektoliter,     Hundreds. 
Kiloliter.     Thousands. 
Myrioliter.     Ten  thous. 


b  INTR  OD  UCTION. 

§  10.  How  to  Learn  the  Metric  System. — According  to  our  expe- 
rience, there  are  three  chief  requisites  : — 

§  11.  1.  Absolute  certainty  of  the  significance  of  gram,  liter  and  meter, 
as  the  units  of  measure  of  weight,  capacity  and  length,  respectively. 

With  the  child  or  unlearned  person,  this  may  be  purely  an  effort  of  memory.  But 
most  persons  can  save  something  by  connecting  gram  with  gravity,  liter  with  liquid,  and 
meter  with  measure,  or  with  the  word  itself  as  it  occurs  in  thermometer,  barometer,  etc. 

§  12.     2.  Certainty  of  the  force  of  the  prefixes. 

With  the  child,  this  too  is  a  matter  of  memory.  But  the  prefixes  of  the  names  of  the 
divisions  are  from  the  Latin,  while  those  of  the  multiples  are  from  the  Greek.  Since  Oreek 
increases  while  Latin  diminishes,  it  has  been  proposed  to  combine  the  initials  of  the  four 
words  in  a  single  mnemonic  word  gild.  We  suggest,  instead,  that  the  gr.  of  Oreek  be  asso- 
ciated with  the  same  letters  in  greater,  and  that  Latin  and  less  have  the  same  initial. 

Deciy  centi,  and  mille  are  familiar  to  most  persons  in  the  words  decimate,  centipede 
and  millipede,  while  deka,  hekto  and  kilo,  are  known  to  some  in  decade,  decalogue,  heka- 
tomb,  and  chiliad.  Of  these  six  prefixes,  however,  centi,  milli  and  kilo,  are  much  more 
often  used  than  the  others. 

§  13.     3.  Personal  familiarity  with  some  metric  measure. 

The  shortest  and  surest  way  to  a  knowledge  of  the  metric  system  is  to  carry  some 
metric  measure,  or  have  one  always  at  hand.  The  five-cent  nickel  piece  is  3  centimeters 
in  diameter,  and  weighs  5  grams.  The  student  is  advised  to  carry  a  metric  rule  in  the 
pocket,  and  to  keep  another  always  upon  the  table. 

The  prices  of  Rules  and  Tapes  vary  from  3  cents  to  as  many  dollars.  A  list  of  the 
styles  and  prices  may  be  obtained  from  the  American  Metric  Bureau  (A),  and  from  dealers 
in  such  articles. 

Pig.  1 


IHIHHIHIHIUiS 


Fig.  1.  A  section,  about  one  tenth,  of  the  paper  meter-yard,  furnished  for  20  cents 
by  the  American  Metric  Bureau  (A,  No.  26,  410).  The  face  has  the  meter  and  the  yard 
side  by  side,  and  the  back  bears  a  complete  Table  of  metric  and  English  equivalents, 
embracing  198  separate  entries.  The  whole  folds  into  the  length  of  a  decimeter,  so  as  to 
be  easily  carried  in  the  pocket,  and  the  Table  may  be  consulted  without  unfolding  the 
paper.     "  Moisture  affects  the  absolute  length,  but  not  the  accuracy  of  comparison." 


METRIC    EQUIVALENTS.  7 

Teachers  may  aid  the  introduction  of  the  system  by  obtaining  metric  Models  and 
Apparatus,  by  hanging  metric  Charts  upon  the  walls,  by  making  their  own  diagrams  on 
cloth  a  yard  wide  but  a  meter  long,  and  by  pointing  to  them  with  the  graduated  Sticks 
of  one  or  two  meters  in  length.  But  the  best  of  all  agencies  is  the  placing  of  some  metric 
measure,  if  only  the  5-cent  rule,  in  the  hands  of  each  pupil. 

An  efficacious  yet  inexpensive  way  of  diffusing  elementary  information:  and  arousing 
curiosity  respecting  the  system  is  to  employ,  in  business  correspondence,  envelopes  or 
postal  cards  bearing  a  metric  ruling  along  one  edge.  This  ruling  is  done  free  of  charge 
by  the  Metric  Bureau. 

§  14.     Reduction  to  and  from  the  Present  System.— Pending  the 

universal  adoption  of  the  metric  system,  it  is  often  necessary  to  effect  a 
reduction  to  and  from  the  older  measures. 

The  following  Table  of  Equivalents  is  selected  from  the  Tables  on  the 
back  of  the  ^^  meter-yard,"  (Am.  Met.  Bureau,  A,  444-448),  in  Foster  and 
Langley,  (A,  263),  and  in  Egleston,  (A). 


Abbreviations. 

Measures. 

Accurate. 

Approximate. 

cm. 

centimeter. 

0.393  in. 

.4    in. 

c.  c,  or  cu.  cm. 

cubic  centimeter. 

0.033  fl.  oz. 

.03  fl.  oz. 

fl.  oz. 

fluid  ounce. 

29.578  c.  c. 

30       c.  c. 

ft. 

foot. 

0.304  meter. 

.3    m. 

ft. 

(C 

30.479  cm. 

30       cm. 

U.  S.  gall. 

U.  S.  wine  gallon. 

3.785  liters. 

3.8    1. 

U.  S.  gill. 

U.  S.  wine  gill. 

118.31    c.  c. 

118       c.  c. 

gr.  Troy. 

Troy  grain. 

.064  gram. 

.06  g. 

g- 

gram. 

15.432  gr.  Troy. 

15.5    gr. 

" 

" 

0.564  dram  avoir. 

.6    dr.  av. 

" 

" 

0.035  oz.  avoir. 

.03  oz,  av. 

in. 

inch. 

2.539  cm. 

2.5    cm. 

kilo.,  or  kg. 

kilogram. 

2.204  lb.  avoir. 

2.2    lb,  av. 

"             '♦ 

" 

2.679  lb.  Troy. 

2.7    lb.  Troy. 

'<             « 

" 

32.15    oz.  Troy. 

32       oz.  Troy. 

14                               (t 

" 

35  27    oz.  avoir. 

35       oz.  av. 

km. 

kilometer. 

0.621  mile. 

.6    m. 

1. 

liter. 

0.264  U.  S.  gall. 

,25  gall. 

»t 

" 

1.056  U.  S.  quarts. 

1       qt. 

" 

(( 

2.113  U.  S.  pints. 

2.1    pt. 

m. 

meter. 

0.546  fathom. 

.5    fath. 

" 

" 

1.093  yard. 

1.1  yd. 

(< 

u 

9.842  hands. 

10       bd. 

«< 

" 

3.280  feet. 

3.3    ft.            > 

<( 

tt 

39.370  inches. 

39.4    in. 

mile. 

mile. 

1.609  kilometers. 

1.6    km. 

mm. 

millimeter. 

0.039  inch. 

.04  in. 

//, 

"  micromillimeter." 

0.001  mm. 

0.000039  in. 

micron. 

.00004 

oz.  avoir. 

ounce  avoirdupois. 

28.349  grams. 

28.35    g. 

oz.  Troy. 

ounce  Troy. 

31 .103  g. 

31         g. 

U.  S.  pt. 

LT.  S.  pint. 

0.473  liter. 

.5     1. 

lb.  avoir. 

pound  avoir. 

0.453  kilo. 

.45    kg. 

lb.  Troy. 

pound  Troy. 

0.373  kilo. 

,37   kg. 

U.  S.  qt. 

U.  S.  quart. 

0.946  liter. 

.95    1. 

yd. 

yard. 

0.914  meter. 

.9      m. 

8  INTRODUCTION, 

The  "micromillimeter"  is  not  an  original  member  of  the  Metric  System,  and  the 
desirability  of  using  the  word  is  strongly  questioned.  In  either  case,  the  symbol  for  the 
thousandth  of  the  millimeter  should  be  the  Greek  //  rather  than  ramm. 

§  15.  The  Metric  System  in  Medicine. — Notwithstanding  the 
obvious  and  considerable  hindrances  to  a  change  involving  commercial  inter- 
ests, the  new  system  is  surely  though  slowly  making  its  way  among  Physicians 
and  Pharmacists. 

The  matter  is  constantly  discussed  in  the  Medical  Journals,  and  "  Reduction  Tables  " 
have  been  published  in  very  compact  form.  Dr.  Kreider  has  one,  in  the  Medical  Record 
for  Oct.  23,  1880 ;  Dr.  F.  H.  Brown  has  another  in  "  The  Medical  Register  for  New  Eng- 
land," which  has  been  reprinted  as  a  pocket  leaflet  by  the  Metric  Bureau  ;  while  another 
leaflet,  first  printed  by  the  Metric  Bureau  (A,  345-348),  by  Dr.  E.  Wigglesworth,  presents 
"  The  Metric  System  in  a  Nut-shell,"  with  especial  reference  to  the  needs  of  the 
medical  profession. 


ZOOLOGICAL  CLASSIFICATION. 

§  16.  As  this  is  in  no  sense  a  treatise  upon  either  Zoology  or  Com- 
parative Anatomy,  but  simply  a  guide  to  certain  practical  methods  of  work, 
we  give  only  such  an  outline  of  the  Classification  of  Animals  as  may  serve  to 
indicate  the  generally  accepted  taxonomic  relations  of  the  forms  here  con- 
sidered. 

Fuller  information  and  discussion  of  this  matter  may  be  found  in  the  works  and 
papers  of  Gegenbaur,  Hseckel,  Huxley,  Owen,  etc.,  and  in  the  condensed  Summary  of 
Pascoe  (A)  ;  see  also  Balfour,  A,  ii,  1. 

It  did  not  seem  worth  while,  in  the  accompanying  Table,  to  indicate  the  view  enter- 
tained by  many  Zoologists,  that  the  primary  division  of  both  the  Animal  Kingdom  and 
the  Vertebrate  Branch  is  dichotomous :  the  one  into  the  Protozoa  and  the  Metazoa ;  the 
other  into  the  Acrania  and  the  Craniota. 

The  names  of  the  eight  animals  more  or  less  fully  treated  of  are  given  in 
the  column  at  the  right  of  the  page.  One,  the  ammha,  is  a  member  of  the 
lowest  division  of  the  Animal  Kingdom,  the  Protozoa,  and  consists  of  but  a 
single  cell,  a  mass  of  nearly  homogeneous  but  nucleated  protoplasm. 

The  other  seven  belong  to  the  highest  division,  the  branch  Vertebrata, 
the  essential  character  of  which,  as  will  be  more  fully  indicated  farther  on, 
is  that  there  is  a  dorsal  and  a  ventral  cavity,  between  which  is  a  sub-cylin- 
drical axis  of  membrane,  cartilage,  or  bone. 

Man,  the  Cat,  Dog,  and  Eabbit  are  members  of  the  class  Mammalia, 
including  the  Vertebrates  which  are  warm-blooded,  and  are  brought  forth 
alive.  The  Frog  and  Menobranchus  are  Amphibia  or  Batrachians,  which 
differ  from  the  Reptiles  in  having  gills  or  water-breathing  organs  at  some 
period  of  their 


CLASSIFICA  TION. 


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ih  INTR  OB  UCTION. 

The  lowest  vertebrate  is  the  little  Ampliioxus  lanceolatus,  usually  assigned 
to  a  distinct  class,  the  Acrania.  Between  the  Amphioxus  and  the  Amphibia 
are  all  the  '^fishes/'  common  and  uncommon,  including  the  Sharks  and 
Eays,  and  many  for  which  there  are  no  popular  names.  Likewise,  between 
the  Amphibia  and  the  Mammals  are  the  classes  Reptiles  and  Birds,  no  exam- 
ples of  which  are  herein  considered. 


IV.— TERMINOLOGY. 

§  22.  Whoever  does  any  systematic  practical  work  in  anatomy,  whether  by  investi- 
gation or  teaching,  is  impelled,  sooner  or  later,  to  suggest  some  modifications  of  the  lan- 
guage previously  employed  in  recording  or  communicating  observations  and  ideas. 

Such  modifications  are  often  put  forth  in  publications  without  explanation  or  apology, 
and  their  subsequent  adoption  by  others  may  then  depend  less  upon  their  intrinsic  value, 
than  upon  the  reputation  and  authority  of  the  proposers. 

In  the  following  pages,  especially  in  the  account  of  the  Brain,  there  will  be  found  a 
few  new  words,  for  the  introduction  of  which  reasons  will  be  duly  offered. 

Many  other  words  and  phrases  will  appear  more  or  less  unusual,  some  to  one  reader 
and  some  to  another.  Those,  however,  who  are  most  familiar  with  the  best  original 
anatomical  publications  in  not  only  their  own  language,  but  also  those  of  other  nations, 
will,  upon  careful  scrutiny,  perceive  that  the  present  work  really  contains  very  few  terms 
for  which  there  Is  not  sound  precedent  in  the  writings  of  recognized  authorities,  in  the 
use  of  either  the  same  words,  or  of  words  analogous  in  character  and  formation. 

From  the  productions  of  working  anatomists  in  all  parts  of  the  world  we  have 
endeavored  to  select,  without  bias  or  partiality,  the  terms  which  seem  to  us  best  suited  to 
the  object,  and  most  easily  used. 

As  a  whole,  therefore,  the  Terminology  here  employed  is  that  of  no  one  nation  or 
writer.  Much  less  should  it  be  regarded  as  our  own,  excepting  in  so  far  as  we  have 
succeeded  in  our  efforts  to  combine  the  elements  from  various  sources  into  a  consistent  and 
homogeneous  whole. 

But  while  the  prestige  of  authoritative  precedent  might  lead  us  to  make  a  personal 
trial  of  any  assemblage  of  terms,  it  would  not,  by  itself,  warrant  an  introduction  into  a 
purely  elementary  work  like  the  present.  It  is  proper,  therefore,  to  gay  that,  with  very 
few  exceptions,  all  of  the  names  and  descriptive  terms  here  employed  have  withstood 
the  severe  practical  test  of  use  by  a  large  number  of  students  for  from  one  to  seven 
years. 

This  test  is  called  severe  because  these  students  have  been  comparatively  mature, 
and  have  done  practical  work  in  anatomy  with  the  view  of  becoming  either  naturalists, 
teachers  or  physicians  ;  and  because  they  have  not  simply  listened  to  lectures  in  which 
the  terms  were  used,  but  have  been  required  to  employ  them  in  writing  their  own  de- 
scriptions of  parts ;  because,  finally,  they  have  been  urged  to  make  suggestions  and  criti- 
cisms with  entire  freedom. 

On  what,  therefore,  may  be  called  experimental  grounds,  we  feel  justified  in  present- 
ing this  Revised  Terminology  of  Anatomy  to  students  other  than  our  own  ;  but  since 
each  year  has  brought  about  some  change  therein,  we  have  no  reason  to  think  it  perfect 
or  complete,  and  we  ask  the  co-operation  of  all  who  may  undertake  to  follow  out  our 
directions  with  the  view  of  rendering  it  better  adapted  to  the  needs  of  Practical  Workers 
in  Anatomy. 


ANATOMICAL    TERMINOLOGY,  11 

§  23.  Some  General  Considerations  upon  Anatomical  Terminology. — These 
remarks  are  based  largely  upon  an  article  ( Wilder,  ,9),  which  although  published  under 
the  name  of  the  senior  author,  was  prepared  with  the  advice  and  co-operation  of  the 
junior. 

That  article  referred  more  particularly  to  the  brain,  but  covered  most  of  the  questions 
connected  with  the  naming  and  description  of  other  parts.  Hence  the  following  expres- 
sions, the  only  published  comments  which  have  come  under  our  notice,  may  fairly  be 
considered  applicable  to  the  whole  subject : — 

"  The  Nation  "  for  April  31,  1881,  contains  a  brief  notice  of  the  article,  evidently  by 
an  experienced  teacher  of  Anatomy,  containing  the  admission  that  "  there  is  certainly 
ample  room  for  a  Reform  of  Anatomical  Nomenclature." 

The  following  are  extracts  from  a  Letter  {Spitzka,  7)  to  the  editor  of  "  Science,"  pub- 
lished  in  that  journal  for  April  9, 1881,  by  Dr.  E.  C.  Spitzka,  the  author  of  many  papers 
upon  the  Anatomy  of  the  Brain  : — 

"  It  is  with  mingled  pleasure  and  profit  that  I  have  read  the  very  suggestive  paper  on 
cerebral  nomenclature  contributed  to  your  latest  issues  by  Professor  Wilder.  Some  of 
the  suggestions  which  he  has  made  have  been  latent  in  my  own  mind  for  years,  but  I  have 
lacked  the  courage  to  bring  them  before  my  colleagues.  Now  that  he  has  broken  ground, 
those  who  prefer  a  rational  nomenclature  to  one  which,  like  the  present  reigning  one,  is 
based  upon  erroneous  principles,  or  rather  on  no  principles  at  all,  will  be  rejoiced  at  the 
precedent  thus  set  for  innovations.  *  *  *  He  who  has  himself  been  compelled  to  labor 
under  the  curse  of  the  old  system,  the  beneath,  below,  under,  in  front  of,  ins-ide,  external, 
between,  etc.,  will  look  upon  the  simple  mntral,  dorsal,  lateral,  mesal,  cephalic,  proximal, 
caudal,  distal,  etc.,  as  so  many  boons.  I  have  no  hesitation  in  saying  that  the  labor  of 
the  anatomical  student  will  be  diminished  fully  one-half  when  this  nomenclature  shall 
have  been  definitely  adopted.     *    *    * 

In  proceeding  to  comment  on  some  of  the  terms  proposed  by  Professor  Wilder,  I 
wish  it  to  be  distinctly  understood  that  I  do  so  merely  tentatively  and  to  promote 
discussion  ;  in  so  doing  I  feel  certain  that  I  am  carrying  out  that  writer's  wish.  It  is 
but  just  to  state  that  the  majority  of  the  terms  cannot  be  discussed  ;  they  are  perfection 
and  simplicity  combined." 

With  the  permission  of  the  writer,  "  Science  "  for  May  28,  1881,  printed  the  following 
Letter  {Holmes,  1),  from  one  who  has  been  the  Professor  of  Anatomy  in  the  Harvard 
Medical  School  for  more  than  the  third  of  a  century  : — 

*'  Boston,  May  3,  1881. 

"Dear  Dr.  Wilder: — I  have  read  carefully  your  paper  on  Nomenclature.  I 
entirely  approve  of  it  as  an  attempt,  an  attempt  which  I  hope  will  be  partially  successful, 
for  no  such  sweeping  change  is,  I  think,  ever  adopted  as  a  whole.  But  I  am  struck  with 
the  reasonableness  of  the  system  of  changes  you  propose,  and  the  fitness  of  many  of  the 
special  terms  you  have  suggested. 

"  The  last  thing  an  old  teacher  wants  is,  as  you  know  full  well,  a  new  set  of  terms  for 
a  familiar  set  of  objects.  It  is  hard  instructing  ancient  canine  individuals  in  new  devices. 
It  is  hard  teaching  old  professors  ne\v  tricks.  So  my  approbation  of  your  attempt  is  a  sic 
vos  non  vobis  case  so  far  as  I  am  concerned.     *    *    * 

"  What  you  have  to  do  is  to  keep  agitating  the  subject,  to  go  on  training  your 
students  to  the  new  terms — some  of  which  you  or  others  will  doubtless  see  reasons  for 
changing — to  improve  as  far  as  possible,  fill  up  blanks,  perhaps  get  up  a  small  manual  in 
which  the  new  terms  shall  be  practically  applied,  and  have  faith  that  sooner  or  later  the 
best  part  of  your  innovations  will  find  their  way  into  scientific  us3.     The  plan  is  an  ex- 


12  INTRODUCTION, 

cellent  one  ;  it  is  a  new  ganneat  which  will  fit  Science  well,  if  that  capricious  and  fantastic 
and  old-fashioned  dressing  lady  can  only  be  induced  to  try  it  on. 

"Always  very  truly  yours, 

"Oliver  Wendell  Holmes." 

See  also  Appendix,  §  1443. 

That  Terminology  is  worthy  of  attention,  is  indicated  also  by  the  care 
bestowed  upon  the  language  of  modern  Chemistry  and  Mathematics,  and  by 
the  following  Aphorisms : — 

§  24.  "  Questions  of  Definition  are  of  the  very  highest  importance  in 
Philosophy,  and  they  need  to  be  watched  accordingly." — Duke  of  Argyll^  1. 

**Inall  sciences.  Nomenclature  is  an  object  of  importance;  and  each 
term  should  convey  to  the  student  a  definite  meaning." — Dunglison,  A, 
Preface. 

^*  Every  art  is  full  of  conceptions,  which  are  peculiar  to  itself ;  and,  as 
the  use  of  language  is  to  convey  our  conceptions  to  one  another,  language 
must  supply  signs  for  those  conceptions." — Huxley,  C,  14. 

*^ Everything  in  Science  ought  to  be  real,  ingenuous  and  open;  every 
expression  that  indicates  duplicity,  or  equivocation,  reservation,  wavering  or 
inconsistency,  is  a  reproach  to  it." — Barclay,  A.,  89. 

"  There  is  a  necessity  for  perfect  definiteness  of  language  in  all  truly 
Scientific  work."— P.  G.  Tait,  1. 

**  Technical  terms  are  the  tools  of  thought."  * 

**  Only  an  inferior  hand  persists  in  toiling  with  a  clumsy  instrument, 
when  a  better  one  lies  within  his  reach.  *  *  *  A  single  substantive  term 
is  a  better  instrument  of  thought  than  a  paraphrase." — Oioen,  A,  I,  pp. 
xii,  xiv. 

'*  As  morphology  deals  with  forms  and  relations  of  position,  it  demands 
a  careful  selection  of  terms  and  a  methodical  nomenclature." — Goodsir,  A, 
II,  83. 

"  To  designate  the  locations  of  organs  by  the  relation  of  animals  to  the 
surface  of  the  earth  is  as  far  from  philosophical  as  it  would  be  to  define  the 
position  of  a  house  or  of  a  tree  by  reference  to  the  planet  Jupiter." —  Wilder, 
9,  122. 

The  progress  of  Comparative  Anatomy  has  been  hindered  by  the  use  of 
anthropotomical  terms  and  methods. 

^'  There  is  not  one  person  in  a  hundred  who  can  describe  the  commonest 
occurrence  with  even  an  approach  to  accuracy." — Huxley,  C. 

^'The  test  of  the  accuracy  and  completeness  of  a  description  is,  not  that 
it  may  assist,  but  that  it  cannot  mislead." —  Wilder,  9,  123. 

Errors  of  personal  equation  are  diminished  by  the  use  of  exact  terms. 

■*  Perhaps  some  of  our  readers  can  supply  the  source  of  this  aphorism. 


METHODS    OF    TERMINOLOGICAL     CHANGE.  13 

"  A  name  is  a  short  substitute  for  a  definition,  and  where  no  definition 
exists,  there  can  be  no  name." — Packard  and  Cope,  1. 

"  The  one  essential  of  naming  is  that  distinct  objects  shall  have  distinct 
names ;  and  the  second  essential  is,  that  each  object  or  concept  shall  have 
but  one  name." — Idem. 

**Life  is  too  short  to  spend  in  digging  for  Truth  with  a  long-handled 
shovel  when  a  trowel  will  serve  the  purpose ;  nor  is  it  becoming  that  any 
nation,  however  wise  and  great,  should  ask  all  the  rest  to  take  their  intel- 
lectual food  with  chop-sticks  of  its  peculiar  pattern." — Wilder,  9,  124. 

"The  personal  convenience  and  preferences  of  all  existing  anatomists 
should  be  held  as  of  little  moment  as  compared  with  the  advantages  which 
reform  may  ensure  to  the  vastly  more  numerous  anatomical  workers  of  the 
future."— i  Jem,  137. 

The  two  following  may  serve  to  show  that  we  have  not  been  unmindful  of  the 
dangers  and  disadvantages  of  terminological  change. 

"Nothing  is  more  pernicious  than  to  attempt  to  tamper  with  well- 
understood  and  universally  accepted  symbols." — Anonymous  Revieiuer  ("The 
Athenaeum,"  June  4,  1881). 

"He  who,  affected  by  the  cacoethes  reformandi,  insists  upon  reform  for 
the  sake  of  an  ideal  perfection,  is  apt  to  appear  as  nothing  better  than  a 
troublesome  and  useless  pedant." —  Wilder,  9,  124. 

§  25.  Brief  Statement  of  the  Objects  and  Methods  of  the 
Terminological  Changes  here  made. — To  render  the  Vocabulary  of 
Anatomy  equally  applicable  to  all  Vertebrates,  and  equally  intelligible  to  all 
Nations. 

To  facilitate  the  Kecognition  of  parts  by  students,  and  lessen  the  labor 
of  Memorizing. 

To  abridge  the  Length  of  Descriptions,  and  at  the  same  time  increase 
their  Accuracy. 

To  include  in  this  Vocabulary,  so  far  as  practicable,  only  such  terms  as  are 
brief,  simple,  exact,  significant,  of  classical  origin,  and  capable  of  inflection. 

To  propose  as  few  changes  as  possible,  and  to  introduce  new  names  only 
for  parts  apparently  unknown  or  unnamed  before  (e.  g.,  crista  fornicis),  or 
in  the  place  of  semi-descriptive  appellations  undesirably  long  or  incapable 
of  inflection,  as  e.  g.,  cimbia  for  tr actus  transversus  pedunculi,  porta  for 
foramen  Monroi. 

To  consider  brevity  as  an  especially  desirable  characteristic  of  such  names 
as  are  most  frequently  employed. 

When  a  part  is  known  by  a  descriptive  phrase,  to  select  therefrom  some 
characteristic  word  as  the  technical  designation;  e»  g.,  iter  {a  tertio  ad 
ventriculwn  q^iartum). 


14  INTRODUCTION. 

When  two  or  more  parts  are  similar,  or  have  similar  relations,  to  distin- 
guish them  by  joining  to  some  common  title  already  in  use,  prefixes  indica- 
tive of  their  relative  positions  ;  e.  g.,  postgeniculatum,  prcegeniculatunu 

To  shorten  the  names  of  several  parts  by  omitting  the  word  corpus,  and 
using  the  neuter  adjective  as  a  substantive. 

To  keep  modern  usage  and  the  rules  of  classical  etymology  constantly  in 
mind,  but  not  to  be  hindered  thereby  from  the  employment  or  even  the 
formation  of  terms  which  are  eminently  desirable  from  the  practical  stand- 
point. 

To  discard  terms  which  indicate  size,  those  which  refer  to  the  natural 
attitude  of  man  or  animals,  most  vernacular  names,  and  all  names  of  the 
reproductive  organs  which  have  been  applied  needlessly  to  other  parts. 

The  terms  employed  by  anatomists  form  two  divisions :  those  which  indi- 
cate th.Q  position  or  direction  of  organs,  and  those  by  which  the  organs  them- 
selves are  designated.  Since,  also,  wTiters  have  often  treated  of  them  sepa- 
rately, it  will  be  convenient  here  to  consider  anatomical  toponomy  and 
organonomy  under  distinct  headings. 

§  26.  Designation  of  Organs — Organonymy. — There  are  probably 
few  investigators  or  teachers  of  comparative  anatomy  who  have  not  been 
impressed,  in  some  degree,  with  the  desirability  of  some  modification  of  the 
prevailing  nomenclature  of  organs, — the  "bizarre  nomenclature  of  anthro- 
potomy,"  (Owen,  A,  II,  143) — based  ^s  it  is  upon  the  peculiar  features  of 
the  human  body,  which  has  been  fitly  characterized,  from  a  morphological 
point  of  view,  afi  "not  a  model,  but  a  monstrosity." 

This  impression  may  give  rise  to  special  papers,  like  those  of  Owen,  (166), 
Maclise  {1),  and  Pye-Smith  (1),  or  simply  to  more  or  less  extended  remarks 
upon  the  subject,  with  or  without  the  use  or  presentation  of  new  terms. 

More  than  one  hundred  pages  of  Vicq  d'Azyr's  great  Anatomy  (A)  are 
devoted  to  a  "  Vocabulaire  anatomique,  augmente  d'un  grand  n ombre  de 
termes  nouveaux." 

In  the  Preface  to  his  "  Anatomic  du  Chat "  (A,  pp.  xiv — xvii),  Straus- 
Durckheim  devotes  several  pages  to  a  discussion  of  anatomical  nomenclature, 
and  the  body  of  the  work  contains  many  original  names.  Professor 
H.  S.  Williams  calls  attention  (A,  Preface),  to  the  "crying  need  of  a  stand- 
ard and  uniform  nomenclature  of  comparative  anatomy." 

In  the  Preface  to  their  recent  account  of  the  morphology  of  the  skull 
(A),  Parker  and  Bettany  say  :  "  It  has  been  attempted  to  narrate  the  facts 
by  means  of  a  consistent  terminology,  amplifying  what  Prof.  Huxley  has  so 
admirably  developed."  Several  of  Huxley's  papers  (as  70),  contain  new 
terms,  most  of  which  have  been  generally  accepted,  and  in  a  greater  or  less 
degree  the  same  is  true  of  the  elder  Agassiz  (A),  Gegenbaur  (59),  Haeckel 
(A),  Marsh  (1),  and  others. 


IMPORTANCE    OF   BREVITY,  15 

§  27.  Nomina  Impudica. — Several  parts,  especially  of  the  brain,  have 
received  names  originally  applied  to  portions  of  the  reproductive  apparatus 
whicli  they  were  fancied  to  resemble.  While  it  may  perhaps  be  urged  in 
extenuation  that  the  pair es  anatomici  entertained  a  notion  as  to  the  representa- 
tion of  the  entire  organism  in  the  brain,  some  of  their  terms  certainly  indicate 
an  entire  freedom  from  apprehension  that  the  mysteries  of  encephalic 
anatomy  ever  would  be  discussed  by  ordinary  mortals,  much  less  by  women, 
or  under  circumstances  requiring  propriety  of  speech. 

On  the  other  hand,  many  names  of  general  or  special  application  have 
been,  at  times  or  by  certain  writers,  needlessly  applied  to  the  male  and 
female  organs.  Among  the  50-60  medical  synonyms  for  vulva  are  sinus, 
folUculus,  annulus,  hiatus,  ostium,  sulcus,  trema,  delta,  cava,  fovea,  mesa, 
porta,  and  fundus.  Among  the  70-80  synonyms  of  penis  are  vomer,  vas, 
clavus,  Cauda,  vena,  gladius,  radix,  ramus,  columna,  tvabs,  pyramis,  and 
spina.  These  terms  should  not  be  lost  to  clean  anatomical  uses  because 
heedless  or  filthy-minded  writers  have  so  misapplied  them. 

§  28.  Importance  of  Brevity. — As  has  been  stated,  and  as  will  be 
exemplified  in  the  vocabulary,  we  place  great  stress  upon  brevity  as  a  desira- 
ble characteristic  of  anatomical  terms. 

So  long  as  the  study  of  anatomy  was  nearly  confined  to  members  of  the 
medical  profession,  they  being  comparatively  few  in  number,  and,  by  ancient 
tradition  at  least,  not  wholly  averse  to  clothing  their  discourse  in  a 
sesquipedahan  garb  impenetrable  to  the  vulgar  eye,  it  mattered  little  whether 
the  statement  of  a  given  fact  or  idea  required  one  minute  or  five. 

But  now,  thanks  to  the  popular  writings  of  Agassiz,  Dana,  Gray,  Darwin, 
Hseckel,  Huxley,  Owen  and  others,  in  so  far  especially  as  they  have  aroused 
a  personal  interest  in  the  problems  of  Evolution,  natural  history  instruction 
is  given  systematically  in  all  schools  and  colleges,  and  the  time  seems  to  have 
come  when,  in  the  words  of  the  naturalist  first-named,  "Scientific  truth 
must  cease  to  be  the  property  of  the  few  ;  it  must  be  woven  into  the  common 
life  of  the  world."  It  is  probable,  indeed,  that  those  who  employ  anatomical 
language  to  a  greater  or  less  extent  at  the  present  day  are  at  least  one  hun- 
dred times  as  numerous  as  when  Dr.  Barclay's  praiseworthy  effort  at  reform 
was  received  with  iudifference  or  opposition. 

In  our  opinion,  therefore,  the  single  names  trochiter,  trocliin,epicondylus,  and  epitroch- 
lea  are  worthy  of  adoption  in  place  of  the  compound  terms  greater  and  lesser  tuberosity, 
external  and  internal  condyle  of  the  humerus,  notwithstanding  their  proposer,  Chaussier, 
has  burdened  the  myological  division  of  anatomy  with  the  most  un wieldly  set  of  terms 
that  could  have  been  devised. 

§  29.  Technical  Terms.— It  may  be  asked:  In  the  face  of  this  rapid 
popularization  of  anatomical  knowledge,  is  it  worth  while  to  introduce,  or 
even  to  retain,  any  purely  technical  terms  ? 


16  INTRODUCTION. 

Apparently  some  German  scientists  have  determined  upon  a  negative 
reply  to  this  inquiry,  and  their  papers,  even  those  of  strictly  scientific 
nature,  teem  with  vernacular  words,  and  with  wonderful  compounds 
thereof. 

For  abundant  examples,  the  reader  may  consult  any  **  Dictionary  of 
German  Medical  Terms,"  as  that  of  Cutter  (A). 

If  this  kind  of  verbifaction  be  tolerable  under  any  circumstances,  it  cer- 
tainly would  be  justified  by  the  extent  and  importance  of  the  contributions 
to  knowledge  which  appear  first  in  the  German  scientific  periodicals. 

Upon  this  point,  however,  we  can  do  no  better  than  to  quote  the  very 
recent  judgment  of  one  who  is  at  the  same  time  an  investigator,  a  promoter 
of  "  the  diffusion  of  knowledge,"  and  an  admirer  of  the  methods  and  results 
of  German  science  :  — 

"  Every  art  is  full  of  conceptions  which  are  peculiar  to  itself ;  and,  as  the  use  of  lan- 
guage is  to  convey  our  conceptions  to  one  another,  language  must  supply  signs  for  those 
conceptions.  Either  existing  signs  may  be  combined  in  loose  and  cumbrous  paraphrases, 
or  new  signs,  having  a  well-understood  and  definite  signification,  may  be  invented. 
Science  is  cosmopolitan,  and  the  diSiculties  of  the  study  of  zoology  would  be  prodigiously 
increased  if  zoologists  of  different  nationalities  used  different  technical  terms  for  the  same 
thing.  They  need  a  universal  language ;  and  it  has  been  found  convenient  that  the 
language  shall  be  Latin  in  form,  and  Latin  or  Greek  in  derivation." — Huxley,  C,  14. 

Unless  it  can  be  shown  that  there  is  a  distinction  between  the  methods 
of  designating  entire  organisms,  and  the  parts  thereof,  the  foregoing  passages 
should  silence  the  objections  of  those  who  would  have  us  retain  a  vocabulary 
as  vague  as  was  that  of  Chemistry  in  the  days  of  quicksilver,  vitriol  and 
copperas — a  vocabulary  which  combines  the  ponderous  stiffness  of  the  clois- 
ter with  the  puerile  vagueness  of  the  nursery.  Tuherculum  higeminum 
a7iterius  must  give  way  to  lohi  optici,  or  some  even  shorter  term  ;  while 
trachea  must  take  the  place  of  ivindpipe,  iceasand,  luftrbhre  and  conduit 
cerien. 

Is  it  not  worth  considering,  too,  that  any  avoidance  of  the  use  of  technical 
terms  is,  after  all,  only  partial  and  delusive  ?  The  principal  human  organs 
have,  of  course,  received  popular  names  which  may,  in  great  measure,  be 
applied  to  the  other  Vertebrates,  especially  the  Mammals.  But  there  are 
many  other  organs  of  which  the  butcher  takes  little  or  no  account.  Shall 
we  construct  vernacular  phrases,  and  write  of  the  liver-veiJif  the  kidney- 
artery,  the  gullet-nerves,  and  the  sweetbread-tuie  9  Unless  we  are  prepared 
to  give  up  such  convenient  and  elastic  terms  as  hepatic,  renal,  'pancreatic, 
pulmonary,  cardiac,  etc.,  why  should  not  the  student  be  informed,  at  the 
outset  of  his  anatomical  and  physiological  enquiry,  that  nearly  all  the  divi- 
sions and  appendages  of  the  principal  organs  have  received  titles  derived  from 
the  classical  names  of  the  organs  themselves?     These  derivatives  and  com- 


TECnytCAL    TERMS.  17 

pounds  would  then  have  some  significance,  instead  of  appearing  like  trouble- 
some verbal  complications. 

So  too  with  the  names  of  the  various  groups  of  animals,  nearly  all  of  which 
are  based  upon  the  technical  names  for  some  of  the  organs.  The  determined 
*' vernacularist"  may  delude  himself  with  the  belief  that  he  is  defying  the 
classics  in  calling  Amphiozus  by  the  name  Lancelet ;  but  he  cannot  appre- 
ciate the  progress  or  the  present  condition  of  systematic  zoology  without 
learning  that  to  the  same  lowest  vertebrate  have  been  applied  the  terms 
acrania,  leptocardia,  cirrostomi,  ceplialochorda,  and  pharyngobranchii.  Why 
then  should  he  not  have  been  informed  already  that  cardia,  cirrus,  stoma, 
pharynx  and  branchia  are  technical  names  for  heart,  gill,  etc.  ? 

In  short,  while  the  small  beginnings  of  Physiology  and  Zoology  maybe  ac- 
quired by  the  use  of  vernacular  words  alone,  any  considerable  progress  in  exact 
knowledge  would  be  excessively  inconvenient  if  not  impossible,  at  least  with 
the  French  or  English  student,  without  the  aid  of  a  certain  number  of  tech- 
nical terms, 

Nor  are  these  terms  so  numerous  as  to  constitute  anything  more  than  a 
purely  sentimental  burden.  As  has  been  well-said  by  one  who  is  in  the 
position  to  recognize  to  the  full  the  value  of  purely  classical  training,  "  A 
doctor,  lawyer,  or  popular  exhorter  who  cannot  learn  by  heart,  in  a  w^eek, 
all  the  technical  terms  and  phrases  of  Latin  origin  which  he  encounters  in 
his  common  professional  occupation,  has  not  wits  enough  for  his  calling." 
Eliot,  1,  359, 

That  there  is  no  inherent  obstacle  to  the  employment  of  t-echnical  terms 
of  classical  derivation  is  shown  by  the  readiness  with  which  such  words  as 
petroleum  and  phylloxera  have  become  domesticated  along  with  the  objects 
which  they  represent.  There  are  scores  of  animals,  like  the  Rhinoceros, 
Hippopotamus,  and  Iclmeumon,  for  which  there  are  no  English  vernacular 
names  ;  while  the  youngest  student  of  Botany  accepts  Hepatica,  A?iemone, 
and  even  Rhododendroii  without  difficulty  or  hesitation.  Homely  as  it  sounds, 
utomacli  is  of  classical  origin,  and  the  use  of  caul  for  omentum^  sweet-bread 
for  pancreas,  or  blind-gut  for  cmcum,  would  surprise  a  class  in  Elementary 
Physiology. 

Even  the  late  Jeffries  Wyman,  who  saw  no  objection  to  forearm,  and 
used  near  rather  than  proximal  for  the  first  row  of  carpalia,  accepted  inter- 
memhral  as  "  good,"  and  freely  employed,  if  indeed  he  did  not  originate,  the 
adjective  pretibial,  which  probably  would  have  come  into  general  use  had 
not  the  bone  in  question  proved  to  be  the  homologue  of  the  intermedium. — 
(Morse,  18,  13.) 

§  30.     Names  Indicative  of  Relative  Position.— Where  four  or  more 
similar  parts  form  a  series,  they  are  usually  numbered  1,  3,  3,  4,  etc.,  begin- 
ning with  the  one  nearest  the  head,  or  the  middle  line,  as  the  case  may  be. 
Thus,  of  the  ribs,  the  first  is  next  to  the  neck;  among  the  several  groups  of 
2 


1 8  JNTR  OB  UCTTOm 

vertebrse,  cervical,  thoracic,  and  lumbar,  the  most  cephalic  is  the  first ;  so 
too,  in  the  normal  position  of  the  limbs  (to  be  explained  farther  on),  the 
pollex  and  primus  (great  toe)  are  on  the  borders  nearer  the  head,  and  may 
sometimes  be  designated  as  the  first  digit  and  dactyl. 

In  designating  the  fractional  portions  of  the  length  of  a  bone,  the 
proximal  half,  third,  fourth,  fifth,  etc.,  is  the  first ;  the  rest  following  in 
order  toward  the  distal  end. 

When,  however,  the  series  embraces  only  two  or  three  similar  parts,  the 
general  name  for  them  all  has  been  usually  followed  (in  Latin)  or  preceded 
(in  English)  by  some  w^ord  indicative  of  relative  position ;  as,  e.  g.,  processus 
superior,  and  middle  commissure. 

This  plan  effects  a  saving  in  the  number  of  different  words  without  the 
risk  of  ambiguity,  just  as  when  we  say  John  Smith  senior,  junior,  and  third. 
But  all  such  terms  are  open  to  the  objection  of  being  compound,  and  there- 
fore incapable  of  inflection. 

In  some  cases,  therefore,  the  more  general  terms  have  been  combined 
with  the  distinctive  prefixes  to  form  single  words,  like  supraspinatus  and 
mesoglutcBus.  Owen  has  also  employed  (A,  III,  519)  postcava  and  proecava 
and  the  senior  author  has  proposed  (32,  306)  entopectoralis  and  ectopectoralis, 
and,  more  recently  (9  and  11),  a  series  of  similar  names  for  parts  of  the 
brain;  e.  g.,  prcecommissura,  medicommissura,  postcominissura,  etc. 

§  31.  The  Limits  of  Terminological  Change. — As  has  been  stated 
already,  the  modifications  here  proposed  are  intended  to  provide  for  what  seem 
to  be  actual  necessities,  irrespective  of  purely  theoretical  considerations,  and 
of  any  desire  for  a  perfectly  uniform  and  consistent  terminology.  It  may  be 
well,  however,  to  specify  certain  general  limitations  to  changes  of  anatomical 
nomenclature. 

Priority  is  practically  of  little  moment  in  respect  to  the  names  of  organs, 
since  it  is  usually  difficult  to  ascertain  when  and  by  whom  they  were  first 
applied.  An  example  of  this  is  afforded  by  the  phrase  foramen  of  Monro, 
(Wilder,  S).  Nor,  indeed,  has  priority  always  been  held  sacred  in  systematic 
zoology.  Owen's  ^^Deinosaurians"  was  proposed  nine  years  later  than  von 
Meyer's  *' Pachypoda;"  yet,  as  stated  by  Huxley  (108^  33),  it  has  been 
retained,  notwithstanding  the  small  size  of  some  members  of  the  group. 

Etymological  appropriateness  is  sometimes  disregarded,  as  in  the  case 
just  mentioned,  and  in  the  more  familiar  names  Reptiles,  Vertebrates, 
Edentates,  etc.  Prof.  Huxley  has  recently  expressed  the  common  sense  view 
of  the  matter  as  follows : — 

"If  well  understood  terms  which  have  acquired  a  definite  scientific 
connotation  are  to  be  changed  whenever  advancing  knowledge  renders  them 
etymologically  inappropriate,  the  nomenclature  of  taxonomy  will  before  long 
become  hopelessly  burdened."    (C,  16.) 

So,  too,  the  names  of  organs  have  sometimes  been  given  in  reference  to 


LIMITS    OF    TERMINOLOGICAL    CHANGE.  19 

some  variable  or  unessential  character,  or  have  even  conveyed  an  erroneous 
idea ;  yet  no  one  now  thinks  of  discarding  either  rectum,  arteria,  or  carotid. 

Sometimes  even  brevity  and  etymological  accuracy  yield  to  established 
usage.  The  word  cubitum,  proposed  by  the  senior  author  in  1872  (lO,  21) 
as  the  technical  equivalent  of  fore-arm,  is  both  shorter  than  antehracMum, 
and  more  in  accordance  with  its  classical  employment;  but  the  latter  word 
seems  to  be  more  generally  preferred,  and  we  are  ready  to  accept  it. 

In  another  case,  even  though  a  new  term  has  not  yet  come  into  general 
use,  a  special  vitality  may  be  imparted  to  it  by  the  authority  of  those  who 
may  have  adopted  it.  No  marked  or  persistent  disfavor  is  likely  to  be  shown 
to  terms  which,  like  myelon,  can  claim  Prof.  Owen  as  father,  and  find  a  god- 
father in  Prof.  Huxley. 

Even  Milne-Edwards,  while  intimating  (A,  XI,  234)  that  anatomical 
nomenclature  has  been  created  in  sufficient  perfection,  frankly  admits  the 
superiority  of  myelon  over  moelle  epiniere, 

§  32.  Some  Inconsistencies. — It  will  be  noted  (Fig.  6)  that  we  have 
refrained  from  giving  technical  names  to  the  membral  arthra  (joints)  or 
have  merely  added  them  in  parentheses. 

This  is  partly  because  the  need  of  names  for  parts  so  familiar  seems  less 
urgent  than  in  the  case  of  some  other  organs.  Still,  it  is  certainly  undesir- 
able that  the  carpo-metacarpal  arthron  should  be  called  wrist  in  man,  and 
knee  in  the  horse,  and  the  chief  cause  of  our  inconsistency  in  this  respect 
has  been  our  inability  to  decide  upon  the  relative  merits  of  the  various 
names  which  might  be  applied.  The  names  suggested  are  those  which  were 
proposed  by  the  senior  author  in  1871  (10,  21-24) ;  but  they  do  not  appear 
to  have  been  adopted  to  any  considerable  extent. 

Strict  logical  consistency,  also,  would  impel  us  to  substitute  entoscapular 
for  subscapular  in  the  designation  of  a  fossa  and  muscle  of  the  scapula  ;  so 
too,  supraspinous,  supraspinatus,  infraspinous,  and  infraspinatus,  should 
be  prcBspinatus,  etc.;  notwithstanding  the  demands  of  consistency  and 
logic,^and  the  example  of  Owen  (A,  III,  44),  we  decline  to  interfere  with 
these  brief  and  old-established  titles  of  well-known  parts. 

Farther  information  concerning  the  changes  in  the  names  of  organs  will  be  given  in 
the  Index  and  in  the  Lists  and  Tables  of  names  in  the  several  chapters. 

It  will  be  noted,  also,  that  of  the  two  Latin  names  for  heart  we  have 
adopted  the  longer  cardia,  rather  than  the  shorter  cor.  This  is  because 
derivatives  and  compounds  of  the  former  are  by  far  the  more  numerous  and 
familiar.  Hence  the  selection  is  really  in  accordance  with  the  more  general 
principle  that  all  measures  of  reform  should  have  regard  to  the  practicability 
as  well  as  the  abstract  suitability  of  a  change. 

The  case  with  stomach  is  less  simple;    although  the  word  is  directly 
-  derived  from  the  Greek  ardfjidxog,  it  is  practically  a  vernacular  terra,  while 


20  INTR  OB  UCTION. 

most  of  the  derivatives  and  compounds  are  formed  from  the  Latin  gaster. 
Perhaps  we  should  have  adopted  the  latter  as  the  technical  designation  for 
the  organ. 

§  33.  Names  and  Abbreviations  on  the  Figures.— Whatever  may 
be  the  practice  of  different  writers,  probably  all  will  agree  that  figures  for  the 
information  of  students,  and  especially  such  as  are  to  be  used  in  dissection, 
are  more  helpful  if  the  following  conditions  are  observed : — 

1.  So  far  as  possible,  the  technical  names  of  the  parts  should  be  written 
upon  the  parts  themselves. 

2.  Where  there  is  not  room  for  the  names  upon  the  figure  itself,  they 
should  generally  be  written  at  the  side,  and  connected  with  the  parts  by 
distinct  lines. 

3.  When  abbreviations  are  employed,  they  should  be  of  the  technical 
rather  than  of  the  vernacular  terms,  and  should  be  uniform,  at  least  for  all 
figures  of  the  same  organ  or  region. 

Whoever  examines  the  figures  in  the  present  work  will  see  that  an 
attempt  has  been  made  to  conform  to  the  above  named  conditions.  That 
success  has  been  only  partial,  will  be  at  once  anticipated  and  excused  by  all 
who  have  undertaken  the  same  task.  The  need  of  abbreviation  was  gi'catest 
with  the  brain,  where  many  distinct  parts  are  crowded  within  a  small  space. 
Here,  as  a  rule,  only  names  of  more  general  application,  such  as  Fissura^ 
Gyrus,  Sulcus,  etc.,  and  their  abbreviations,  have  been  commenced  with 
capitals  ;  but  this  distinction  has  not  been  observed  in  all  other  cases. 

In  the  explanations  of  the  figures,  the  abbreviations  are  given  in  alpha- 
betical order. 

§  34.  Terms  of  Position  and  Direction — Toponymy. — Like  other 
solids,  the  body  of  an  animal  has  six  general  aspects. 

As  with  other  elongated  solids,  these  aspects  are  two  ends  and 
four  sides. 

Were  the  body  simply  a  mass  of  homogeneous  material,  like,  for 
example,  an  oval  of  wood,  the  supporting  side  would  be  called  the  bottom, 
and  described  as  the  lower  side  ;  the  opposite  side  would  then  be  upper,  and 
be  called  top  ;  of  the  two  other  sides,  either  might  be  called  right,  and  the 
opposite  would  then  be  left;  finally,  either  of  the  two  ends  might  b^ 
named  front,  and  the  other  end  would  then  be  known  as  hacTc.  To  indicate 
the  two  ends  as  anterior  and  posterior,  and  the  top  and  bottom  as  superior 
and  inferior,  would  render  only  more  evident  the  fact  that  the  various 
aspects  of  the  mass  are  determined  and  named  according  to  their  relations 
to  the  observer,  ov  to  the  surface  of  the  earth. 

But  with  the  animal  body,  at  least  the  body  of  the  adult  vertebrate, 
there  are  constant  and  more  or  less  marked  distinctions  between  the 
opposite  ends  and  sides,  so  that  these  various  aspects  have  fixed  and  definite 
relations  to  one  another  and  to  certain  other  objects  or  influences. 


THE    NORMAL    POSITION,  21 

Food  and  drink  are  received  at  one  end  of  the  body,  and  the  organs  of 
special  sense  are  there  located.  Between  one  of  the  sides  and  the  nervous 
cord  known  as  the  myelon  or  spinal  cord,  there  always  intervenes  a  subcylin- 
drical  rod,  usually  of  bone  or  cartilage,  the  Columna  vertehralis,  or  sjnnal 
colufmiy  while  the  opposite  side  is  not  so  separated  from  the  myelon.  The 
two  remaining  sides  differ  less  from  one  another,  but  distinctions  have  been 
observed,  some  of  which  have  been  commented  upon  by  the  senior  author 
in  papers  12,  13,  and  18. 

It  is  obvious  that  the  comparison  of  the  corresponding  aspects  in  different 
animals  will  be  more  easily  made  and  more  instructive,  if  the  animals  can  be 
placed,  actually  or  ideally,  in  some  common  position,  and  if  the  aspects  can 
be  called  always  by  the  same  names. 

§  35.  The  Normal  Position  of  the  Body. — Taking  as  the  natural 
attitude  of  an  animal  that  which  it  assumes  in  ordinary  locomotion,  there 
are  wide  differences  among  Vertebrates.  The  head  of  man  points  directly 
away  from  the  earth,  and  the  longitudinal  axis  of  the  body  forms  a  right 
angle  with  its  surface  ;  with  the  gorilla  and  some  other  apes  the  axis  is 
slightly  inclined  ;  with  birds  it  forms  a  smaller  angle  with  the  supporting 
surface;  but  with  the  larger  number  of  vertebrates  the  body  is  nearly  or 
quite  horizontal. 

As  the  question  is  entirely  one  of  bodily  organization,  and  has  no  refer- 
ence to  mental  or  spiritual  preeminence,  there  never  has  been  made  any 
serious  objection  to  regarding  the  normal  position  of  vertebrate  animals 
as  that  of  the  majority  of  them,  in  which  the  body  axis  is  horizontal,  and 
the  aspect  nearer  the  earth  is  that  which  is  separated  from  the  myelon  by 
the  Columna  vertebraHs. 

§  36.  Designation  of  the  Aspects. — Instead,  however,  of  applying 
to  the  various  aspects  names  naturally  suggested  by  the  parts  themselves, 
irrespective  of  the  particular  attitude  assumed  by  the  animal,  anatomists, 
probably  influenced  by  the  greater  practical  importance  of  the  human  body, 
have  almost  universally  employed  terms  which  are  strictly  applicable  only  to 
man  in  the  erect  attitude.  In  order,  therefore,  that  a  comparison  might  be 
instituted  between  corresponding  parts  of  man,  a  cat  and  a  fish,  it 
was  necessary,  at  least  constructively,  to  erect  the  two  latter  upon  their 
tails. 

Notwithstanding  the  logical  inconsistency  of  such  a  course,  and  the  risk 
of  misunderstandings,  no  effort  at  reformation  seems  to  have  been  made 
until  early  in  the  present  century,  when  Dr.  Barclay,  the  anatomical  pre- 
ceptor of  Professor  Owen,  published  a  little  volume  (A)  entitled:  '^  A  New 
Anatomical  Nomenclature,  relating  to  the  Terms  which  are  expressive  of 
Position  and  Aspect  in  the  Animal  System." 

§  37.  The  key  note  of  Barclay's  view  of  the  subject  is  struck  in  the 
following  paragraph  : — 


22  INTRODUCTION. 

"  The  vague  ambiguity  of  such  terms  as  superior,  inferior,  anterior,  posterior,  etc., 
must  have  been  felt  and  acknowledged  by  every  person  the  least  versant  with  anatomical 
description." 

Some  of  Barclay's  new  terms  have  been  occasionally  used  by  Owen,  but 
most  of  his  contemporaries  and  immediate  successors  seem  to  have  been  quite 
indifferent  to  his  suggestions,  and  only  within  a  comparatively  few  years  has 
the  subject  again  received  attention. 

Dunglison  admits  (A,  61)  that  "  Great  confusion  has  prevailed  with 
anatomists  in  the  use  of  the  terms  before,  behind,  etc."  Spitzka  forcibly 
states  ( 1,  75,  note  1)  the  objections  to  the  use  of  anterior,  etc.,  and  refers 
(7,  165)  to  the  gradual  disuse  of  the  equivalent  German  terms  by  Henle, 
Gudden  and  others ;  more  exact  terms,  also,  are  occasionally  employed  by 
several  writers  who  do  not  explicitly  condemn  the  current  toponomy;  Coues, 
1,  150;  Cleland,  1,  170;  Gegenbaur,  A,  491;  Rolleston,  B,  33,  note; 
Huxley,  2. 

In  previous  publications  (A,  69,  and  1,  fere)  Mivart  more  or  less  consist- 
ently discards  anterior  and  posterior,  and  his  recent  work  (B,  258,  note,)  cha- 
racterizes them  as  "Unfortunate  as  applied  to  a  quadruped  like  the  cat." 

Finally,  the  need  of  a  radical  "change  of  base"  has  been  proclaimed  in 
one  of  the  very  strongholds  of  anthropotomy :  — 

"  Now  that  the  more  extended  study  of  comparative  anatomy  and  embryonic  develop- 
ment is  largely  applied  to  the  elucidation  of  the  human  structure,  it  is  very  desirable  that 
descriptive  terms  should  be  sought  which  may,  without  ambiguity,  indicate  position  and 
relation  in  the  organism  at  once  in  man  and  animals.  Such  terms  as  cephalic  and  caudal, 
dorsal  and  mntral,  etc.,  are  of  this  kind,  and  ought,  whenever  this  may  be  done  con- 
sistently with  suflBcient  clearness  of  description,  to  take  the  place  of  those  which  are  only 
applicable  to  the  peculiar  attitude  of  the  human  body." — Quain,  A,  i,  6, 

This  is  certainly  explicit  as  to  the  principle  involved,  and  it  is  to  be 
hoped  that  later  editions  of  this  standard  Human  Anatomy  may  display  its 
practical  application  to  the  body  of  the  work. 

The  ambiguity  here  alluded  to  is  not  merely  hypothetical.  In  a  recent 
work  (Mivart,  B)  the  M.  sterno-mastoideus  is  described  (p.  134)  as  arising 
"beneath  the  anterior  part  of  the  pectoralis  major,"  but  on  p.  145  a  part  of 
the  M.  ectopectoralis  is  said  to  arise  "beneath  the  manubrium  [prgester- 
num]."  In  the  former  case  beneath  means  entad  of  or  dorsad  of,  while  in  the 
latter  the  same  word  signifies  ectad  of  or  ventrad  of.  The  experienced 
human  or  comparative  anatomist  may  know  what  is  intended,  and  the  con- 
text would  enable  any  one,  with  a  little  study,  to  determine  the  matter  by 
exclusion ;  but  there  are  so  many  instances  in  which,  by  reason  of  the  ab- 
sence of  planes  and  straight  lines,  the  context  must  be  depended  upon  in  a 
greater  or  less  degree,  that  needless  ambiguities  should  be  avoided. 

The  foregoing  illustration,  however,  by  no  means  exhausts  the  list  of 
possible  ambiguities.    In  the  normal  position  of  a  vertebrate,  the  heart  is 


THE    IXTRIXSIC    TOPONOMY.  23 

beneath  the  Columna  vertehralis;  in  the  natural  attitude  of  man,  it  is 
beneath  the  bifurcation  of  the  trachea ;  in  the  position  in  which  both  man 
and  quadrupeds  are  commonly  dissected,  the  heart  is  beneath  the  sternum  ; 
finally,  it  may  be  said  to  be  beneath  the  ribs  or  the  M3f.  intercostales  in  the 
sense  of  being  covered  by  them.  The  single  English  word  here  means  suc- 
cessively ventrad  of,  caudad  of,  dorsad  of,  and  entad  of  the  organs  on  four 
different  sides  of  it.  Whatever  may  be  thought  best  by  the  writers  of  de- 
scriptions for  advanced  students,  we  hold  that  the  use  of  such  terms  in  a 
work  expressly  designed  for  beginners  would  be  little  else  than  a  self-stulti- 
fication of  its  authors  and  a  mockery  of  its  readers. 

§  38.  The  Intrinsic  Toponymy. — Following  the  suggestion  of  Bar- 
clay, and  the  more  or  less  consistent  example  of  the  other  writers  above 
named,  we  shall  wholly  discard  all  terms  which  "  contain  an  allusion  to  the 
situation  of  different  objects,  as  they  stand  with  respect  to  the  heavens  and 
the  earth  ;"  and  shall  designate  the  aspects  and  regions  of  the  body  by  terms 
derived  from  names  which  have  been  applied  to  the  parts  themselves.  Hence 
we  shall  speak  of  the  cei)lialic  and  the  caudal  ends  or  aspects  or  regions  ;  of 
the  dorsal  and  ventral  aspects  or  regions ;  and  of  the  dextral  and  sinistral 
aspects  and  regions. 

Such  terms  constitute  a  Toponymical  Vocabulary  which  is  based  upon 
intrinsic  instead  of  purely  extrinsic  and  accidental  relations. 

§  39.  Cephalic  and  Caudal.— Barclay  proposed  the  words  atlantal 
and  sacral  for  the  designation  of  the  position  of  parts  lying  toward  the  head 
or  the  tail  in  reference  to  an  imaginary  plane  dividing  the  body  at  about  the 
middle  of  its  length. 

In  many  of  the  lower  vertebrates,  however,  there  is  no  distinct  atlas  or 
sacrum,  and  in  any  case  these  terms  would  not  apply  strictly  to  parts  beyond 
the  bones  in  question  ;  hence  Barclay  devised  for  the  head  an  entirely  new 
set  of  terms,  inial,  glabellar,  etc.  So  far  as  we  know,  atlantal  and  sacral 
occur  only  in  the  writings  of  Owen  (A,  III,  519)  and  Turner  [1,  819). 

Thacher  has  employed  {1,  282  and  292)  orad  as  both  adjective  and 
adverb,  but  the  correlative  aborad,  which  might  have  been  expected,  has  not 
been  observed  by  us  in  his  papers. 

Cephalic  and  caudal  are  employed  by  Cleland  {!),  and  are  re(^mmended 
by  Quain  as  stated  above.  Their  signification  is  obvious,  and  practically 
there  seems  to  be  no  serious  objection  to  their  use,  although  it  is  possible  to 
imagine  cases  where  some  ambiguity  might  arise  from  the  fact  that  each  is 
employed  in  two  senses,  the  one  relative,  and  the  other  absolute.  For 
example,  in  the  absolute  sense,  only  the  vertebrae  of  the  tail  are  caudal ; 
but  relatively,  c«Mc?fl^?  may  be  used  to  designate  one  or  more  vertebrae  in  any 
part  of  the  series,  which  are  situated  nearer  than  others  to  the  caudal  end  of 
the  body.  So  too,  we  may  speak  of  the  caudal  aspect  of  the  skull,  or  of  the 
cephalic  members  of  the  series  of  caudal  vertebrae. 


24  INTRODUCTION, 

§  40.  Dorsal  and  Ventral. — By  their  derivation,  and  by  their  appli- 
cation to  distinctly  differentiated  and  universally  recognized  regions,  these 
two  terms  are  perfectly  acceptable  so  far  as  the  vertebrates  are  concerned. 

Should  the  alleged  correspondence  of  the  ventral  region  of  the  Vertebrate  with  the 
tergal  region  of  the  Arthropod  prove  to  be  one  of  true  homology,  it  may  be  desirable  in 
time  to  discard  dorsal  and  ventral  for  more  suitable  terms,  but  for  the  present,  if  on 
practical  grounds  alone,  it  seems  well  to  retain  them. 

As  stated  above,  these  are  among  the  terms  recommended  in  Qiiain,  and 
they  have  been  somewhat  generally  employed  by  s^atomists  ;  Huxley,  A,  1 
et  seq. ;  Owen,  A,  III,  3  ;  Sanders,  1  ;  Hadlich  /,  97,  note ;  Mivart,  A,  G9, 
B,  263  and  1,  fere. 

To  avoid  ambiguity,  it  will  be  better  to  employ  dorsal  only  in  the  sense 
here  indicated,  and  to  characterize  the  costiferous  vertebras  as  thoracic. 

§  41.  Dextral  and  Sinistral.  —  These  are  simply  more  technical 
equivalents  of  the  English  right  and  left.  No  objection  has  been  made  to 
them,  or  substitutes  offered  for  them. 

§  42.  Lateral. — Usually  the  two  sides  are  so  similar  that  what  is  true 
of  the  one  is,  approximately  at  least,  true  also  of  the  other.  Hence  it  is 
often  desirable  to  employ  a  general  term  applicable  to  either  or  both  the  right 
or  the  left.  Such  a  term  is  lateral^  the  derivation  of  which  properly  indi- 
cates the  fact  that,  as  compared  with  the  two  ends  or  the  top  and  bottom, 
the  right  and  the  left  are  the  sides.  Lateral  is  therefore  a  more  general 
term,  while  dextral  and  sinistral  are  specific. 

§  43.  Mesal. — In  the  restricted  literal  sense  of  entering  into  the  com- 
position of  the  head  or  the  tail,  certain  parts  may  be  said  to  be  absolutely 
cephalic  or  caudal ;  but  in  most  cases  these  terms,  like  dorsal  and  ventral^ 
merely  indicate  a  greater  proximity  of  the  part  so  characterized  to  one  or 
the  other  of  the  four  aspects  in  comparison  with  some  other  part,  named  or 
implied.  Even  when  used  in  an  apparently  absolute  sense,  they  are  really 
relative  terms. 

This  is  because  there  has  not  been  detected  any  structural  line  or  plane 
of  demarcation  between  the  two  ends  of  the  body,  or  between  the  back  and 
the  belly. 

But  with  right  and  left,  the  case  is  different.  The  right  eye  and  the 
right  kidney  are  not  simply  nearer  than  the  left  to  the  right  side  or  aspect 
of  the  body ;  they  also  forin  parts  of  the  right  half  of  the  body,  and  this 
half,  notwithstanding  the  numerous  instances  of  continuity,  is  so  readily 
distinguishable  from  the  left,  that  one  may  almost  describe  the  body  as  if  it 
were  formed  by  the  union  of  two  pieces,  similar,  but  reversed  in  form  and 
position. 

The  plane  of  junction  of  the  right  and  left  sides  is  at  or  near  the  middle 
of  the  body,  and  has  been  known  as  the  middle  or  median  plane,  a  longi- 


THE    REGIONS    OF    THE    LIMBS.  35 

tudinal  line  therein  being  called  a  middle  or  median  line.  But  since  certain 
parts  lie  upon  or  cross  this  plane,  and  since  it  is  sometimes  desirable  to 
speak  of  lateral  parts  as  more  or  less  near  it,  Barclay  proposed  (A,  121) 
for  it  the  single  word  mesion. 

We  have  not  met  with  this  word  in  other  writings,  although  mesial  and 
mesiad  are  not  infrequent. 

Nevertheless,  it  seems  desirable  to  designate  this  middle  plane  by  a  single 
word  which  is  at  once  significant,  short  and  capable  .of  inflection. 

Such  a  word  is  meson,  from  the  Greek  ro  fieaov,  the  middle,  equivalent  to 
the  more  ponderous  Latin  meditullium.  This  word  and  its  derivatives  were 
proposed  {0)  by  the  senior  author. 

For  convenience,  any  point  or  line  therein  may  be  called  meso7i,  but  the 
lines  most  frequently  referred  to  in  description  constitute  the  dorsal  and 
ventral  borders  of  the  plane,  and  may  be  known  as  dorsimeson  and  ventri- 
meson  respectively. 

To  avoid  ambiguity,  it  would  be  well  to  employ  mesal  and  its  derivatives 
only  in  reference  to  the  meson  j  intermediate  (middle)  may  then  be  applied 
to  the  second  of  any  series  of  three  similar  parts ;  while  medial  could  be 
used  in  reference  to  the  digitus  medius. 

§  44.  Convenient  additions  to  the  vocabulary  of  toponymy  would  be  terms  of  single 
words,  corresponding  with  meson,  but  indicating  respectively  the  dorsal,  ventral  and  other 
aspects  of  the  body.     We  refrain,  however,  from  making  any  specific  suggestion. 

§  45.  Designation  of  the  Regions  of  the  Limbs. — The  body  as  a 
whole,  with  the  cat  as  with  most  vertebrates,  consists  of  two  general 
divisions,  axial  and  appendicular ;  the  former  is  the  body  projjer  or  soma  ; 
the  latter  are  the  limhs  or  membra. 

On  account  of  the  approximately  vertical  position  of  the  arms  and  legs 
in  the  natural  attitude  of  man,  their  attached  and  free  ends  had  been  called 
superior  and  inferior,  or  upper  and  loiver. 

For  these  terms,  as  inapplicable  to  the  limbs  of  many  animals  (fishes  and 
turtles,  etc.),  as  are  the  terms  anterior  and  posterior  (in  the  anthropic  sense) 
to  the  rest  of  their  bodies,  Barclay  wisely  substituted  proximal  and  distal, 
which  have  been  very  generally  adopted. 

We  speak,  therefore,  of  the  attached  end  of  any  appendage,  as  limb,  ear, 
barbel,  tentacle,  horn,  spine,  as  the  proximal  end,  its  free  or  unattached 
extremity  being  in  like  manner  called  distal.  The  same  terms  apply  to  the 
corresponding  ends  of  the  segments,  bones  and  muscles  of  these  appendages. 

As  has  been  well  remarked  by  Mivart  {2,  509),  ''The  tail,  to  a 
certain  extent,  partakes  of  the  natures  of  both  the  trunk  and  the  limbs. 
It  is  like  the  limbs  in  that  it  is  solid,  that  it  contains  no  body-cavity, 
and  is  not  traversed  by  the  alimentary  canal."  Still,  the  tail  is  really 
a  division  of  the  soma,  and  its  two  ends  should  be  designated  as  cephalic 
and  caudal. 


26  INTR  OB  UCTION. 

Barclay  seems  not  to  have  concerned  himself  for  other  than  English  users  of  his  new 
terms,  and  we  can  only  conjecture  what  he  would  have  made  the  classical  forms  of 
proximal  and  distal.  Following  analogy,  they  may  be  rendered  proximalis  and  distalis, 
though  no  such  Latin  words  exist. 

For  the  four  other  aspects  (borders  or  sides)  of  each  limb;  Barclay 
proposed  the  terms  ulnar,  radial,  anconal  aud  thenar,  tibial,  fibular, 
rotular  and  popliteal. 

These  have  been  employed  to  some  extent  by  later  writers,  but  they  are 
open  to  at  least  three  objections :  they  are  specific  instead  of  general ;  the 
bones  from  which  they  are  derived  are  not  recognizable  in  "fishes;"  with 
many  mammals,  the  ulna  and  radius  are  crossed  instead  of  parallel,  and  with 
some  the  ulna  and  tibia  are  but  slightly  developed. 

Huxley  and  some  other  English  anatomists  have  employed  the  general 
terms  preaxial,  postaxial,  epaxial,  and  hypaxial.  But  these  words  are  liable 
to  misconception  because  axial  has  been  used  already  in  reference  to  not 
only  the  axis  vertebra,  but  also  the  entire  skeleton  of  the  trunk  as  contra- 
distinguished from  that  of  the  limbs. 

Perhaps  the  chief  objection  to  all .  these  terms  is  that  they  are  not  really 
necessary,  and  introduce  undesirable  verbal  comphcations. 

The  limbs  are  certainly  part  of  the  body,  and  whether  or  not,  as  held  by 
Thacher  (2)  and  Mivart  (i),  they  are  essentially  and  primarily  only  isolated 
and  differentiated  portions  of  continuous  lateral  fold,  there  seems  to  be  a 
general  assent  to  Huxley's  proposition  (4)  that,  for  comparison,  the  limbs 
should  be  regarded  as  extended  laterad  at  right  angles  ivith  the  soma. 

Hence  it  seems  to  us  most  natural  to  apply  to  the  aspects  of  the  limbs  the 
same  terms  which  are  applied  to  the  corresponding  regions  of  the  soma. 
Thus  each  limb  presents  a  dorsal  and  a  ventral  aspect,  a  cephalic  and  caudal 
aspect,  and  a  proximal  and  distal  end. 

§  46.  Terms  of  General  Application  to  the  Whole  Body.— Central 
and  peripheral  were  proposed  by  Barclay,  and  have  been  very  generally  used 
by  anatomists.  They  are  especially  applicable  to  the  parts  of  the  nervous 
and  vascular  systems,  since  the  vessels  and  the  nerves  may  be  said  to  radiate 
from  or  converge  to  the  heart  and  the  myelencephalon  (cerebro-spinal  axis) 
as  anatomical  and  physiological  centers. 

Barclay  also  recognized  the  need  of  terms  denoting  nearness  or  remote- 
ness with  respect  to  the  surface  of  any  part  of  the  body,  and  proposed  dernml 
in  the  one  case,  central  doing  duty  also  in  the  other. 

Most  anatomists,  however,  have  contented  themselves  with  the  older 
words,  outer  and  inner,  superficial  and  deep,  sublime  and  profound. 

Of  these  terms,  three  are  incapable  of  inflection  ;  ail  are  very  commonly 
employed  in  a  metaphysical  sense,  and  are  therefore  more  or  less  ambiguous ; 
while  the  last  two  are  quite  inappropriate  to  the  insignificant  structures 
with  which  they  are  often  associated. 


VERBAL    INFLECTIONS.  1ffJ 

The  need  of  other  terms  than  those  in  use  was  so  generally  and  so 
strongly  felt  among  the  students  in  the  Anatomical  Laboratory  of  Cornell 
University  that  the  suggestion  to  employ  ental  and  ectal  was  welcomed,  and 
they  were  published  in  the  article  (.9)  already  mentioned.  Derived  respec- 
tively from  Evrog  and  turo^  their  significance  is  obvious,  while  their  brevity 
and  capacity  for  inflection  will  probably  commend  them  to  accurate  working 
anatomists. 

Both  words  are  already  familiar  in  the  words  ectozoa,  entozoa,  entoptic, 
entoglutceus,  ectoglutceus,  etc.  As  a  rule,  it  will  probably  be  well  to  employ 
them  in  reference  to  lamince  or  surfaces. 

§  47.  Inflections. — Barclay  proposed  that  the  various  adjective  forms 
should  be  converted  into  adverbs  by  substituting  for  the  ending  al  the  let- 
ters ad,  the  Latin  equivalent  of  the  English  ward.  Thus  dorsal,  ventral, 
dextral,  sinistral  and  lateral  became  dorsad,  ventrad,  dextrad,  sinistrad,  and 
laterad.  Substituting  mesal  for  7nesial,  and  cephalic  and  caudal  for  atlantal 
and  sacral,  we  have  in  addition  the  terms  mesad,  ceplialad  and  caudad. 

Proximal,  distal,  ental  and  ectal  are  readily  converted  into  the  adverbs 
proximad,  distad,  entad  and  ectad. 

For  example,  the  dura  (mater)  may  be  described  as  ectad  of  the  brain, 
but  entad  of  the  cranium.  A  part  may  be  divided  by  cutting  either  ecto-entad, 
from  without  inward,  or  ento-ectad,  from  within  outward. 

Th«  adverbial  forms  occur  less  frequently  than  the  adjectives,  but  dorsad 
is  used  by  Huxley,  as  reported  in  Nature,  Jan.  6,  1881,  p.  281,  and  this 
together  with  ventrad  and  mesiad  are  systematically  employed  by  Mivart  in 
a  recent  paper,  {!,)  although  not  in  his  latest  work  (B). 

§  48.  Use  of  the  Prepositions  Of  and  From. — Of  is  used  with 
terms  of  relative  position,  when  the  verbs  to  he  or  to  lie  are  expressed  or 
understood.     Thus  we  say,  the  elbow  is  distad  of  the  shoulder. 

From  is  used  with  active  verbs  implying  extension  or  passage  from 
one  point  to  another;  thus,  the  myelon  extends  caudad  from  the  brain;  the 
humerus  extends  distad  from  the  shoulder,  etc. 

§  49.  Limitations  to  Accuracy. — The  use  of  the  terms  above 
enumerated  certainly  renders  it  possible  to  be  more  definite  in  description. 
Yet  absolute  accuracy  and  exactness  are  often  unattainable,  with  an  animal 
like  the  cat,  where  there  are  few  plane  surfaces  or  straight  lines.  It  often 
becomes  necessary  to  designate  the  relative  positions  of  two  parts,  or  the 
direction  of  a  line  upon  a  more  or  less  curved  or  undulating  surface.  For 
example,  on  Fig.  7  representing  approximately  the  outline  of  a  transection 
of  the  body,  the  point  a  is  obviously  laterad  of  the  point  h.  So  too,  the 
point  c  is  dorsad  of  the  point  d.  But  the  point  c  may  be  described  as 
latero-ventrad  of  h,  or  dorso-mesad  of  d;  it  would  seldom  happen,  however, 
that  the  curvature  should  be  equal  on  both  sides,  and  usually  the  needed  qual- 
ification would  be  supplied  by  the  context. 


Tio  INTRODUCTION. 

§  50.  Derivatives. — With  derivative  words  the  connecting  vowel  is  commonly  i; 
e.  g.,  alipes,  daviger,  fatifer,  fidlcen,  jluctigena,  decimamts,  neurilemma,  and  xiphisternum. 
But  classical  exceptions  are  mulomedicus,  quadrvpedas,  noctuvigilus,  and  decumanus.  In 
common  English  and  scientific  terms  of  Latin  or  Greek  origin  the  o  is  common  ;  e.  g., 
ambodexter,  burgomaster,  ga^trotomy,  termonology,  mntroinguinal,  later o flexion,  mucopuro- 
lent,  vasomotor,  curvograph,  neuroglia,  oculospinal,  pleuroperitoneal,  xiphosura,  septopyra, 
hemoglobin,  cephalotribe,  etc.     Rarely  is  it  e  as  in  venesection. 

Both  analogy  and  euphony  lead  one  to  use  the  i  when  the  first  part  of  the  word  is  of 
Latin  origin,  and  the  o  with  the  Greek. 

Hence  we  have  dorsimeson,  ventrimeson,  dprsicumbent,  later icumbent,  dextriflexion, 
sinistriversion,  cephaloduction,  caudiduction,  etc.  V 

§  51.  Compound  Words. — The  two  Latin  compounds  known  to  us  are  veneri-vagus 
and  vesti-contubernimn.  The  following  common  or  technical  English  compound  words 
are  selected  from  Webster's  English  Dictionary,  or  the  Medical  Dictionaries  of  Dunglison, 
or  Littre  et  Robin,  or  from  the  writings  of  Barclay,  Humphrey  (E),  and  Straus-Durckheim : 
Anglo-Saxon,  concavo-convex,  dextro- gyrate,  ventro- appendicular,  costo-vertebral,  costo- 
alaris,  caudo-pedal,  osseo- cutaneous,  occipito-scapularis,  dorso-lateral,^  meso-dorsal,  sterno- 
clavicular, claoo-cucullaire,  davi- sternal,  davio-humeralis.  By  analogy  with  the  foregoing, 
compound  terms  of  direction  should  read  dorso- ventral,  caudo- cephalic,  meso-lateral, 
sinistro-cephalic,  etc. 

§  52.  Combination  of  Words. — The  names  of  two  or  more  organs  or  tissues  may 
be  conjoined  like  the  words  for  regions  ;  thus  we  say  musculo-tendinous,  or  g astro-hepatic. 
But  the  names  of  organs  are  never  combined  with  the  names  of  regions  ;  hence  such  a 
term  as  dorso-gastric  does  not  occur, 

§  53.  Hybrid  Words. — Some  of  the  terms  already  mentioned  are  formed  by  the 
union  of  Latin  with  Greek  words;  e.g.,  dorsimeson,  meso-lateral,  and  caudo-cephalic ; 
several  others  are  likely  to  be  employed;  e.  g.,  davo-mastoideus,  and  felitojny. 

Beyond  the  occasional  intimation,  in  the  dictionaries,  that  a  term  is  hybrid,  the 
subject  seems  to  be  ignored,  and  it  might  fairly  be  inferred  that  literary  authorities 
entertain  one  or  the  other  of  two  opposite  convictions :  either  mongrel  words  are  verbal 
monstrosities  which  will  be  shunned  instinctively  by  all  well-regulated  minds,  or  there 
is  no  more  serious  objection  to  their  use,  or  even  their  creation,  than  to  the  employment, 
or  even  the  production,  of  mules,  or  the  mixed  varieties  of  grapes  and  roses. 

However  this  may  be,  the  fact  is  that  the  Latin  and  the  Greek  tongues  have 
united  to  form  the  following  nine  hybrids  which  may  be  found  in  Latin  writings : 
anticato,  biclinium,  cryptoporticus,  dentarpaga,  epitogium,  monosolis,  monoloris,  pseudo- 
fl^avus,  and  pseudo-ui'banus.  Of  these,  the  third  only  occurs  with  any  degree  of 
frequency. 

Whoever  will  spend  the  time  to  look  through  an  Unabridged  Dictionary  of  the 
English  language — and  the  interest  as  well  as  the  instructiveness  of  such  a  search  can 
hardly  be  realized  by  those  who  use  the  volume  only  for  occasional  reference — will  find 
that,  after  excluding  the  twenty-five  or  more  words  ending  with  meter,  which  may 
perhaps  be  derived  directly  from  the  Latin  form  metrum,  there  are  more  than  one  hundred 
hybrid  words,  many  of  them  in  good  standing.  Many  more  are  to  be  gleaned  from  the 
Dictionaries  of  Medicine  and  the  other  Arts  and  Sciences. 

Nevertheless,  it  is  probable  that  a  due  regard  for  the  feelings  of  the  classical  purists 
in  whose  eyes  language  was  not  made  for  man,  but  rather  man  for  language,  will  lead 
scientists  to  refrain  from  the  introduction  of  mongrel  terms  when  others  will  serve  the 
purpose,  and  we  shall  be.  pleased  to  receive  suggestions  leading  to  the  substitution  of 
wholly  unobjectionable  words  for  any  of  the  hybrids  which  may  occur  in  the  present  work. 


PRIMARY    DIVISIONS    OF    THE    BODY.  29 

Practical  Application  of  the  Foregoing  Considerations  in  the 
Designation  of  Some  Parts,  and  in  the  Indication  of  their  Relative 
Position  and  Direction. 

§  54.  The  Primary  Divisions  of  the  Body. — Soma  and  Mem- 
bra.— The  entire  body  of  a  normal  and  complete  Vertebrate  presents  a 
principal  axial  portion,  and  an  appendicular  portion,  the  arms  and  legs, 
which  may  be  spoken  of,  collectively,  as  the  limbs  or  membra. 

Neither  the  classical  nor  the  vernacular  terms  for  these  divisions  have 
been  used  with  desirable  exactitude.  With  the  ancients,  corpus  might 
signify  either  the  entire  body,  or  the  trunk  as  distinguished  from  the  head, 
while  the  English  body  may  refer  to  either  the  whole  body  in  distinction 
from  the  mind,  the  axial  part  in  distinction  from  the  appendicular  part,  or 
the  principal  portion  of  the  former  in  distinction  from  the  head  and  the  tail. 
Triincus  usually  meant  the  body  apart  from  the  limbs,  but  the  head  and  the 
trunk  are  sometimes  spoken  of  as  distinct  regions. 

In  view  of  this  lack  of  discrimination  we  venture  to  suggest  that  the 
entire  physical  part  of  an  animal  be  called  the  corpus  or  body  ;  that  tr uncus 
and  trunk  be  applied  only  to  that  part  of  the  axial  portion  which  intervenes 
between  the  neck  and  the  tail  ;  and  that  the  entire  axial  portion,  including 
head,  neck,  trunk  and  tail  be  denominated  the  soma. 

It  is  true  that  the  Greek  aoyfia  was  generally  equivalent  to  the  Latin 
co?yjs,  and  that  many  of  its  derivatives  and  compounds  refer  to  the  entire 
organism  ;  but  the  term  somatome  was  proposed  by  Goodsir  to  indicate  a 
vertebral  segment,  of  which  the  limbs  are  merely  occasional  components. 
Somite  and  somatopJeure  are  used  by  Balfour,  A,  II,  3,  141. 

The  undesirability  of  the  introduction  of  a  somewhat  unfamiliar  term  is 
fully  admitted.  It  is  probable,  however,  that  it  need  not  be  employed  very  often. 

§  55.  Figure  2  is  a  diagram  of  the  dorsal  aspect  of  the  cat,  intended  to 
illustrate  certain  very  general  features  of  it  or  of  any  other  vertebrate 
provided  with  two  pairs  of  limbs. 

The  outline  of  the  soma  is  elliptical,  the  larger  end  corresponding  to  the 
head,  and  the  smaller  with  the  tail. 

The  arms  and  legs  are  represented  as  lateral  appendages  projecting  at 
right  angles  with  the  longitudinal  somatic  axis,  or  meson. 

Each  limb  has  an  attached  or  proximal  end,  and  a  free  or  distal  end. 

The  right  and  left  sides  of  the  entire  body  are  antitropic  or  symmetrical 
with  each  other ;  that  is,  they  are  reversed  repetitions  of  one  another  in 
opposite  directions. 

§  56.  Beginners  in  Anatomy  are  sometimes  confused  by  the  fact  that, 
with  some  figures,  the  right  is  at  their  own  right,  while  with  others  the 
right  of  the  figure  is  upon  their  left. 

This  confusion  may  be  avoided  by  a  preliminary  exercise  with  a  familiar 
object  :  —   . 


30 


INTRODUCTION, 


arm 


SimtraL 
UMlfS 


dtsjtcU  tncL 


Fiq,%  JJoraai  aspect 


sinistra  I 


dixAraL 

-enter  on 


1      ^iynir  , 
(7)1  em  6  rum) 

Fig.  o.  TtamectLon 


•^  ^  oN       ventral 

^V^  Fio.4^  Hemi section 


Diagrams  of  Thuee  Aspects  op  a  Vertebrate, 
exhibttina  the  most  general  features. 


THE    POSITION    OF    FIGURES.  31 

Hold  a  hook  and  note  its  several  aspects — the  top  and  hottorn,  the  hack 
and  front,  the  right  and  left  sides.  For  the  purpose  of  comparison,  these 
aspects  may  be  considered  to  correspond  with  the  head  and  caudal  aspect, 
the  hack  and  the  helly,  the  right  and  left  sides  of  a  man  or  a  cat. 

When  the  book  is  held  so  as  to  permit  the  reading  of  a  title  printed 
across  the  back,  the  various  aspects  coincide  in  position  and  direction  with 
the  body-aspects.  The  right  is  at  the  right  of  the  observer,  and  the  left  at 
his  left ;  the  back  faces  in  the  same  direction  with  his  own,  while  the  top  of 
the  book  is  upward,  and  its  bottom  down. 

But  when  the  book  is  held  just  ready  to  be  opened,  the  top  and  bottom 
have  the  same  directions  as  before,  but  the  back  and  front,  the  right  and 
left  sides  are  reversed.  The  right  of  the  book  is  opposite  the  left  of  the 
observer,  and  vice  versa. 

In  the  first  case,  the  observer  and  the  book  are  related  as  are  two  persons 
one  behind  the  other;  in  the  second  case,  the  relation  is  that  of  two  persons 
facing  each  other,  and  as  when  one  views  his  own  image  in  a  mirror. 

Again,  if  the  book  is  held  so  that  the  lower  end  is  in  view,  the  right  and 
left  still  correspond  with  those  of  the  observer;  but  if  it  is  turned  so  as  to 
expose  the  top,  then  the  right  and  left  are  reversed.  The  same  difference 
exists  in  the  case  of  transections  of  objects.  If  a  book  were  cut  across,  there 
would  be  exposed  two  cut  surfaces,  the  bottom  surface  of  the  upper  part, 
and  the  top  surface  of  the  lower  part.  With  an  animal,  these  would  be 
called  the  caudal  surface  of  the  cephalic  part,  and  the  cephalic  surface  of 
the  caudal  paj't.  If  the  former  is  viewed,  the  right  and  left  of  the  surface 
coincide  with  those  of  the  observer ;  if  the  latter,  then  the  right  and  left  are 
reversed. 

As  with  objects,  so  with  their  representations  in  pictures  and  diagrams. 
The  right  and  the  left,  the  dorsal  and  the  ventral  aspects,  are  to  be  so  desig- 
nated, whatever  may  he  their  position  on  the  page  or  with  respect  to  the 
ohserver. 

The  foregoing  remarks  concern  symmetrical  figures,  which  represent 
either  the  dorsal,  the  ventral,  the  caudal  or  the  cephalic  aspects  of  an  ani- 
mal, or  its  parts.  As  a  rule,  in  the  present  work,  such  figures  are  so  placed 
that  the  meson  coincides  in  direction  Avith  that  of  the  observer,  and  with  the 
longer  diameter  of  the  page,  as,  e.  g.,  Fig.  2  and  3. 

Figures  which,  like  Fig.  4,  are  unsymmetrical,  and  represent  the  lateral 
aspects  of  animals  or  their  parts,  are  usually  so  placed  that  the  meson  lies 
across  the  page,  and  at  a  right  angle  with  that  of  the  observer.  Usually, 
also,  in  accordance  with  distinguished  precedent,  as  remarked  in  a  paper 
(17)  by  the  senior  author,  the  cephalic  end  of  such  figures  is  turned  toward 
the  left  of  the  page  and  of  the  observer. 

§  57.  Position  and  Direction  on  the  Soma.— The  letters  A,  B,  C, 
D,  E,  F,  G,  H,  I,  K,  with  the  dotted  lines  between  them  are  introduced  for 


32  INTR  OD  UCTWm 

the  sake  of  illustrating  some  of  the  more  common  cases  of  designation  of 
relative  position  and  lines  of  direction. 

The  points  A,  B  and  C  lie  at  or  upon  the  meson,  and  are  therefore  mesal. 
So  also,  the  dotted  lines  between  the  points  are  mesal  lines. 

D  is  not  at  the  meson,  and  is  therefore  laterad  (in  this  case  sinistrad) 
of  B  ;  but  it  lies  nearer  the  meson  than  E,  and  is  therefore  mesad  of  it. 

B  lies  cepJialad  of  0,  but  caiidad  of  A. 

E  lies  latero-cephalad  of  C,  and  latero-caudad  of  A. 

A  lies  meso-cephalad  of  E,  and  C  mesO'Caudad.  The  line  A,  B,  C  is  a 
cephalo-caudal,  or  caudo-cephalic  line,  or  it  may  be  described  as  extending 
caudad  from  A,  or  cephalad  from  C. 

The  line  E,  D,  B,  is  a  rneso-sinistral,  or  si?iistro-mesal  line,  and  may  be 
said  to  extend  either  mesad  from  E,  or  laterad  (sinistrad)  from  B. 

The  line  A,  E  extends  meso-cephalad  from  E,  or  sinistro-caiidad  from  A. 

The  line  A,  B,  0  coincides  with  the  meson,  and  a  cut  upon  it  would  be 
a  hemisection. 

The  line  E,  D,  B,  E'  is  a  transverse  line,  or  at  right  angles  with  the 
meson,  and  a  cut  therein  would  be  a  transection. 

Finally,  an  organ  on  the  meson,  and  represented,  for  instance,  by  B,  is 
not  only  mesal  in  position,  but  also  called  azygous  or  unpaired ;  while  two 
similar  organs,  one  upon  each  side,  and  represented  for  instance  by  E',  are 
lateral  in  position,  and  called  paired  organs.  Each  such  paired  organ  may 
be  called  the  platetrope  of  the  other,  or  its  lateral  homologue,  or  the  fellow 
of  the  opposite  side. 

The  letters  upon  the  right  leg  have  similar  relations,  excepting  that 
proximal  and  distal  take  the  place  of  mesal  and  lateral  or  dextral  and 
sinistral. 

I  and  K,  for  example,  lie  respectively  cephalad  and  caudad  of  G ;  while 
G  lies  caudad  of  I  and  cephalad  of  K.  F  lies  proximad  of  G,  and  G  of  H  ; 
n  is  distad  of  G,  and  the  relative  locations  of  the  three  may  be  designated 
as  proximal,  distal  -and  intermediate. 

A.  The  reasons  for  representing  the  limbs  in  the  position  here  given  them  will  be 
more  advantageously  presented  in  §  80. 

B.  The  dotted  lines  connecting  the  two  extremities  of  the  soma  with  the  distal  ends 
of  the  limbs  illustrate  the  idea  referred  to  on  p.  26  that  the  limbs  are  essentially  remnants 
of  two  continuous  lateral  folds  ;  see  also  Balfour,  A,  III,  501. 

§  58.  Figure  3  represents  an  ideal  transection  of  the  body  of  a  cat,  or 
any  other  vertebrate  possessing  limbs. 

Only  some  of  the  more  constant  and  essential  features  are  here  shown. 

Near  the  middle  of  the  figure  is  the  section  of  the  Columna  vertebralis. 

The  Columjia  vertebralis  or  spinal  column  may  bo  of  bone,  cartilage,  or 
a  semi-solid  material  with  mombninous  walls,  according  to  the  animal  ex- 


THE    BODY   PLANES.  33 

amiiied,  the  degree  of  development,  or  the  part  which  is  divided.  It  lies 
upon  the  meson,  and  serves  therefore  as  a  boundary  between  the  right  and 
the  left  sides  of  the  animal. 

In  most  animals  it  is  located,  in  nearly  its  whole  length,  nearer  that  side 
of  the  body  which  is  commonly  upward  in  ordinary  locomotion ;  that  is,  it  is 
nearer  the  dorsal  aspecL  There  is  no  definite  plane  of  contact  of  the  dorsal 
with  the  ventral  region  as  of  the  right  with  the  left  side  ;  but,  for  convenience, 
the  two  regions  may  be  regarded  as  meeting  at  a  line  X,  X',  passing  from  side 
to  side  through  the  middle  of  the  Columna  vertebralis. 

Dorsad  of  the  Columna  is  a  canal,  the  Oanalis  neuralis^  containing  the 
vnyelencephalon  or  cerebrO'-spmal  axis,  (brain  and  spinal  cord).  Ventrad  of 
the  Columna  is  a  cavity,  usually  more  capacious,  the  cmlum,  or  general  body 
cavity,  in  which  are  the  hearty  alimentary  canal^  and  other  viscera. 

This  arrangement  of  principal  organs,  in  two  cavities,  on  opposite  sides 
(but  not  on  the  right  and  left)  of  a  mesal  axis  is  a  constant  character  of  all 
Vertebrates,  and,  with  perhaps  a  few  exceptions,  is  peculiar  to  the  group. 

§  59.  Figure  4  represents  an  ideal  Jiemisedion  (section  on  the  meson)  of 
such  a  body  as  is  represented  in  figures  in  2  and  3.  The  cephalic  aspect  or 
head  looks  toward  the  left. 

§  60.  The  Body  Planes. — For  the  sake  of  precision  in  the  use  of 
toponymical  terms,  the  planes  already  referred  to  will  be  more  distinctly 
defined ;  see  Fig.  5. 

§  61.  1.  The  Meson.^This  is  a  plane  passing  lengthwise  of  the  body, 
and  dividing  the  whole  into  approximately  equal  and  similar  right  and  left 
halves. 

For  convenience,  the  dorsal  and  ventral  borders  of  this  plane  may  be 
called  the  dorsimeson  and  the  ventrimeson  respectively. 

Organs  like  the  nose,  the  stomach,  and  the  urocyst  (bladder)  appearing 
upon  both  sides  of  the  meson  are  said  to  be  mesaX  or  azygoiis.  They  are,  at 
least  primarily  and  approximately,  symmetrical  in  themselves  ;  that  is,  they 
consist  of  similar  right  and  left  halves. 

Organs  like  the  eyes,  the  lungs,  and  the  kidneys,  which  form  pairs,  the 
one  upon  the  right  and  the  other  upon  the  left  of  the  meson,  are  called 
lateral  or  paired  antitropous  organs.  Either  of  them  is  symmetrical  with 
its  fellow  ( platetrope),  but  not  in  itself. 

§  62.  2.  An  imaginary  transverse,  dorso-ventral  plane,  at  right  angles 
jsith  the  meson,  and  dividing  the  body  into  a  cephalic  and  a  caudal  region. 
^H  §  63.  3.  An  imaginary  longitudinal,  dextro-sinistral  plane,  extending 
^Rne  whole  length  of  the  body,  and  dividing  it  into  a  dorsal  and  a  ventral 
^region. 

H|    These  three  body-planes  correspond  in  direction  with  the  three  dimen- 
^^ons  of  a  solid,  length,  height,  and  tvidth.    Each  is  at  a  right  angle  with 
both  the  others.     The  longitudinal  somatic  axis  lies  in  the  meson. 
3 


34 


INTRODUCTIOX. 


As  already  indicated,  the  position  of  the  meson  is  fixed ;  that  of  the 
other  two  planes  is  purely  conventional  and  for  convenience  in  a  given  case. 


Jyonol   aspect, 


dqyhatk 
aspect 


K  Wntnmeson. 

Veniral  aspect. 

Fig.  5. — Diagram  op  the  three  Body-planes,  with  the 
various  lines  op  direction. 


§  64.  Designation  of  Position  and  Direction.— By  the  use  of  terms 
derived  from  meson,  and  from  the  names  of  the  general  regions  or  aspects 
of  the  body,  it  is  possible  to  designate  positions  and  lines  of  direction  with 
considerable  precision. 

There  are  two  general  cases  : — 

1.  Where  the  points  to  be  located  are  on  a  line  which  itself  lies  in  one  of 
the  three  body  planes,  or  in  a  plane  parallel  to  one  of  them. 

2.  Where  the  points  to  be  located  are  on  a  line  which  is  not  in  either  of 
these  planes,  but  connects  some  two  of  them  like  the  diagonal  of  a  solid ; 
e.  g.,  the  points  H,  K,  at  the  ends  of  the  line  HK. 

Under  case  1,  the  lines  may  be  either  direct  or  ohlique. 

§  Q6.  Direct  lines  may  be  perpendicular  to  the  meson,  as  the  line  SFI, 
or  any  other  line  passing  directly  from  one  side  of  the  body  to  the  other. 
Such  a  line  would  be  the  line  connecting  the  eyes,  or  the  heads  of  two  ribs. 

Direct  lines  may  lie  either  in  the  meson  itself,  or  in  an  imaginary  plane 
parallel  thereto  and  either  parallel  or  perpendicular  to  the  longitudinal 
dorso-sinistral  plane  ;  e.  g.,  ABC  or  MHL.  Such  lines  pass  directly  from 
the  dorsal  to  the  ventral  aspect  of  the  body,  or  from  the  caudal  to  the 
cephalic  aspect. 

All  direct  lines  may  be  also  characterized  as  coinciding  with  the  inter- 
section of  two  of  the  tliree  body-planes,  or  of  jjlcines  parallel  thereto. 


DESIGNATION    OF   RELATFVE    POSITION,  35 

§  66.  Oblique  lines  lie  in  one  plane,  but  are  not  perpendicular  to  either 
of  the  other  planes  ;  neither  do  they  coincide  with  the  intersection  of  two  of 
the  body  planes,  or  of  planes  parallel  thereto.  They  are  comparable  with 
the  diagonal  of  a  parallelogram.     Such  lines  are  EC ;  ME  ;  BH. 

§  67.  Designation  of  Direct  Lines. — This  requires  a  term  of  two 
words,  of  which  one  indicates  the  point  of  departure  and  the  other  the  point 
of  approach. 

On  the  figure  of  the  model,  the  line  ABO  is  a  cephalo-caudal  line,  or 
extends  cejjJialo-caudad  ;  or  the  order  may  be  reversed  by  saying  that  it  is  a 
caudO'cephaUc  line,  or  extends  caudo-cephalad.  The  line  OFK  is  a  dorso- 
ventral  or  ventro-dorsal  line,  and  the  line  IFS  is  dextro-sinistral  or  sinistro- 
dextral, 

§  68.  Designation  of  the  Relative  Positions  of  Points  upon 
Direct  Lines. — This  requires  a  term  of  but  one  word,  adverbial  in  form, 
and  indicating  a  point  of  approach. 

In  Fig.  5,  0  is  cephalad  of  B,  and  dorsad  of  F ;  A  is  caudad  of  B ;  H  is 
ventrad  of  M,  but  dorsad  of  L. 

In  the  body,  the  sternum  is  ventrad  of  the  heart,  the  Columna  vertebralis 
is  dorsad,  and  the  diaphragm  is  caudad  of  the  same  organ. 

In  man,  the  sternum  would  be  said  to  be  before,  or  in  front  of,  or  anterior 
to  the  heart ;  but  in  animals  it  might  be  described  as  below,  under  or  inferior 
to  the  same  organ. 

It  should  be  kept  in  mind  that  these  terms  are  relative,  not  absolute. 
The  diaphragm,  for  example,  lies  cephalad  of  the  stomach,  but  caudad  of  the 
heart. 

§  69.  Designation  of  Oblique  Lines. — This  requires  a  term  of  two 
words,  both  of  which  indicate  points  of  approach.  The  points  of  departure 
are  usually  apparent  from  the  context.  Thus,  the  line  E,  0,  extends  both 
toward  the  head  and  the  back;  hence  it  is  called  a  cephalo-dorsal  line,  or 
described  as  passing  ceplialo-dorsad.  The  same  line  could  be  described  as 
caudo-ventral,  or  as  extending  caudo-ventrad. 

In  man,  such  a  line  would  be  described  as  extending  forward  (ventrad) 
and  downward  (caudad).  In  comparative  anatomy,  it  might  be  said  to  pass 
downward  (ventrad)  and  hachward  (caudad). 

§  70.  Designation  of  the  Relative  Position  of  Points  upon 
Oblique  Lines. — This  requires  a  term  of  two  words,  in  the  adverbial  form. 

On  the  line  CE,  0  is  cephalo-dorsad  of  E,  while  E  lies  caiido-ventrad 
of  C. 

In  man,  C  would  be  said  to  be  above  and  behind;  in  animals,  in  front 
and  above. 

§  71.  Designation  of  Diagonal  Lines  not  in  Either  of  the  Three 
Planes. — This  requires  a  term  of  three  words,  all  of  which  indicate  points 
of  approach ;  the  order  of  the  words  is  immaterial. 


36  INTR  OD  UCTION. 

In  Fig.  5  the  line  HK  may  be  described  as  having  a  dorso-sinistro-caudal 
direction.  In  man,  it  would  be  said  to  extend  backward  (dorsad),  to  the  left 
(sinistrad),  and  downward  (caudad).  But  with  an  animal  it  would  be 
described  as  passing  upward,  to  the  left,  and  backward. 

%  72.  Designation  of  the  Relative  Position  of  Points  upon 
Diagonal  Lines  not  in  Either  of  the  Planes.— A  term  of  three  words 
is  needed,  with  the  adverbial  termination.  Thus  H  is  dorso-sinistro-caudad 
of  K  ;  or  K  is  ventro-meso-cephalad  of  H. 

§  73.  In  all  these  cases,  it  is  sometimes  more  convenient,  and  equally 
intelligible,  to  substitute  for  the  more  specific  terms  dextral  and  siriistral, 
the  more  general  terms  mesal  and  lateral.  The  line  ME,  for  example,  might 
be  called  dorso-lateral  instead  of  dorso-sinistral;  or  it  might  be  called  ventro- 
mesal,  and  the  context  would  show  which  side  was  referred  to.  If,  while 
dissecting  upon  the  left  side,  the  student  were  directed  to  cut  mesad  for 
2  cm.,  he  would  cut  towards  the  right,  that  is  dextrad. 

§  74.  Designation  of  Direction  and  Relative  Position  upon  the 
Limbs. — The  various  terms  are  employed  and  combined  as  for  the  soma, 
excepting  that  in  place  of  mesal  and  lateral,  or  dextral  and  sinistral,  there 
are  used  the  terms  proximal  and  distal. 

§  75.  Ectal  and  Ental,  and  their  Derivatives.— The  general  signifi- 
cance and  uses  of  these  terms  have  been  indicated  in  §  46.  Other  examples 
will  be  given  in  connection  with  Fig.  7. 

A  special  employment  of  the  two  words  in  combination  is  for  the  sake  of 
designating  the  direction  of  an  incision.  Ordinarily  incisions  are  carried 
from  the  surface  inward,  that  is  ecto-entad ;  sometimes,  however,  it  is  desir- 
able to  divide  parts,  especially  the  skin  and  abdominal  parietes,  by  an 
incision  in  the  opposite  direction — ento-ectad. 

§  76.  Figure  6  is  intended  to  show  certain  features  of  the  cat,  regarded 
as  a  Mammal,  and  not  simply  as  a  Vertebrate,  as  in  Figures  2,  3, 
and  4. 

As  in  Fig.  2,  the  body  is  ventricumbent,  so  as  to  expose  the  dorsal 
aspect. 

The  limbs  (arms  and  legs)  are  extended  at  each  side  at  right  angles  with 
the  axis  of  the  soma,  in  what  is  commonly  regarded  as  their  normal  position. 
The  principal  divisions  of  the  body  are  named  in  the  Table  on  p.  39. 
§  77.  The  Soma  and  its  Divisions.— The  largest  division  of  the 
soma  is  the  trunk.  The  tail  forms  an  extension  in  one  direction,  while  the 
other  end  is  continued  as  the  neck  and  head.  The  neck  is  narrower  than 
the  head  or  trunk,  and  the  head  itself  consists  of  the  cranitim  and 
the  face. 

§  78.  The  Trunk  and  its  Divisions.— There  are  readily  distinguished 
three  regions  of  the  trunk.  The  intermediate  region  or  abdomen  has  only 
fleshy  sides,  while  the  more  cdudal— pelvis— has.  the  Os  innominatum  on 


NORMAL    POSITION    OF    THE    LIMBS,  37 

each  side,  and  the  more  cephalic — tliorax — is  enclosed  by  the  ribs  {costce) 
and  their  cartilages  (costicartilagines). 

The  ventral  and  larger  cavities  of  these  three  trunk  regions  are,  strictly  speaking, 
cavum  abdominis,  cavum  pelvis^  and  cavum  thoracis;  but  they  are  usually  called  by  the 
names  of  the  regions  themselves. 

The  abdominal  and  pelvic  cavities  are  continuous;  but  between  the 
abdomen  and  thorax,  in  the  cat  as  in  all  other  Mammals,  there  intervenes  a 
musculo-tendinous  partition — the  diaphragma. 

With  all  the  lower  Vertebrates,  the  diaphragm  is  absent  or  incomplete,  so  that  the 
three  cavities  are  continuous,  and  constitute  the  codwn  or  trunk  cavity.  Sometimes  it  is 
convenient  to  apply  this  general  name  with  Mammals. 

A  part  of  the  alimentary  canal  is  introduced  for  the  sake  of  illustrating 
a  somewhat  peculiar  case  in  the  designation  of  relative  positions  which  will 
be  referred  to  in  connection  with  the  explanation  of  Fig.  7;  §  91. 

§  79.  The  Vertebrae.— As  shown  in  Fig.  30,  in  the  adult  cat,  the 
vertebrae  form  a  continuous  series  from  the  caudal  aspect  of  the  cranium  to 
the  tip  of  the  tail.  In  this  diagram,  however,  only  the  thoracic  vertebrae 
are  shown  by  a  series  of  squares  representing  their  centra  (bodies).  The 
lines  extended  dextrad  from  the  ceittra  indicate  the  right  costce  (ribs).  The 
centra  and  costae  are  included  in  this  diagram  merely  to  illustrate  the 
method  of  notation  of  parts  which  form  a  series.  The  most  cephalic  is 
numbered  1,  etc. 

§  80.  Normal  Position  of  the  Limbs. — For  accurate  comparison  of 
the  limbs  with  each  other,  or  Avith  those  of  other  animals,  it  is  desirable 
that  they  should  be  placed,  or  regarded  as  placed,  in  some  uniform  normal 
position. 

One  of  the  many  possible  natural  attitudes  of  the  cat's  limbs  is  shown  in 
Fig.  30,  and  there  is  great  variety  among  other  Mammals. 

Huxley  has  proposed  (4)  that  all  limbs  should  be  compared  as  if  in  the 
position  shown  in  Figures  2  and  6.  In  this  condition  they  stand  out  at  right 
angles  with  the  body  (soma),  the  extensor  surfaces  (with  the  convexities  of 
the  elbow  and  knee)  being  placed  dorsally,  and  the  flexor  surfaces  ventrally, 
with  both  pair  of  limbs.  This  is  the  position  which  they  have  in  the 
embryo  Mammal,  according  to  Kolliker,  and  it  continues  throughout  life  in 
some  Amphibia  and  Reptiles. 

There  is  some  difference  of  opinion  as  to  whether  the  ventral  aspects  of  the  limbs 
should  not  be  regarded  as  facing  more  or  less  directly  mesad ;  but  in  other  respects 
Huxley's  view  has  been  adopted  by  several  anatomists,  including  Mivart,  Pagenstecher, 
RoUeston,  Flower,  Coues,  and  the  senior  author,  in  whose  paper  (10,  9-17)  will  be  found 
fuller  references.     See  also  Balfour,  A,  II,  508. 

Owing  to  changes  which  occur  after  the  first  formation  of  the  limbs,  it 


distal  segmenfs 


distal  artkra 


middle   se^meijts 
^,mlddU   flrtA^Q-^ 


Fig.  6.— Diagram  of  the  Dorsal  Aspect  of  the  Cat,  with  the  Limbs  in  the 

Normal  Position. 
38 


DIVISIONS    OF    THE    BODY. 


39 


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1 

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< 


a 


en 

p^ 
o 
u 


40  INTRODUCTION 

is  not  easy,  with  most  Mammals,  to  replace  them  in  the  normal  position. 
It  may,  however,  be  readily  accomplished  with  an  orang,  and  without  much 
difficulty  with  the  arms  of  a  cat  or  a  child. 

The  student  may  exemplify  the  normal  position  of  the  arms  approxi- 
mately by  getting  upon  all-fours,  placing  the  palms  upon  the  floor  at  either 
side,  with  the  fingers  pointed  laterad  ;  the  convexities  of  the  elbows  should 
then  be  made  to  look  dorsad  and  laterad,  upward  and  outward.  If  now  the 
arms  be  extended  laterad  to  their  utmost  length,  still  keeping  the  palms 
against  the  floor,  and  the  elbows  away  from  it,  the  limbs  will  have  nearly 
the  position  shown  in  figures  6  and  7. 

§  81.  Limb  Segments. — With  the  cat,  as  with  most  air-breathing 
Vertebrates,  each  limb  presents  at  least  three  divisions  or  seg7nenta,  con- 
nected with  each  other  and  with  the  soma  by  three  arthra  (joints  or 
articulations). 

These  segments  and  arthra  are  thus  proximal,  intermediate,  and  distal. 
As  shown  upon  the  right  of  the  diagram,  the  proximal  segments  are 
hrachium  (upper  arm)  and  meros  (thigh).  The  intermediate  segments  are 
antebracMum  (forearm)  and  cr^is  (leg  proper).  The  distal  segments  are  the 
manus  (hand)  andjoe^  (foot). 

The  entire  limbs  are  joined  with  the  trunk  by  the  shoulder  and  hij) 
joints,  while  the  elhow  and  knee  intervene  between  the  brachium  and  ante- 
brachium,  the  meros  and  crus,  and  the  wrist  and  a^ihle  between  the  ante- 
brachium  and  manus,  the  crus  and  pes  respectively. 

The  technical  names  for  tlie  arthra  placed  in  parenthesis  are  those  which  were  pro- 
posed in  1873  by  the  senior  author  {10,  18) ;  but  as  they  have  not  been  generally  adopted 
they  are  not  insisted  upon  here. 

Each  manus  and  pes  also  presents  a  threefold  division,  carpus,  metacarpus, 
and  digits  (thumb  and  fingers) ;  tarsus,  metatarsus,  and  dactyls  (toes). 

The  distinctive  names  for  the  digits  and  dactyls  are  placed  under  them. 
The  primus  (great  toe)  is  represented  by  a  dotted  line,  in  consideration  of 
its  absence  from  the  cat. 

§  82.  Limb  Bones. — On  the  left  side  of  the  diagram  are  shown  the 
bones  corresponding  to  the  segments  already  enumerated. 

The  proximal  segments  have  each  a  smgle  bone,  the  humerus  and  femur, 
which  are  represented  as  subcylindrical,  with  enlarged  extremities. 

The  intermediate  segments  have  each  two  bones,  ulna  and  radius,  tibia 
and  fibula,  which,  in  the  normal  position  of  the  limbs,  lie  side  by  side,  the 
radius  and  tibia  on  the  cephalic  aspect  of  the  limbs,  and  the  ulna  and  fibula 
on  the  caudal.  These  bones  are  likewise  subcylindrical,  but  the  ulna  and 
tibia  are  larger  at  their  proximal  ends,  while  the  radius  and  fibula  increase 
more  or  less  distad.  The  patella  (knee-pan)  and  the  olecranon  and  other 
special  features  are  not  shown. 


CARPUS    AND     TARSUS.  41 

§  83.  Marsh  has  proposed  {!)  to  apply  general  names  to  the  corresponding  bones  of 
the  arm  and  leg.  Thus,  the  bones  of  the  proximal  segments  are  the  Ossa  propodialia ; 
the  radius  and  ulna,  the  tibia  and  fibula,  constitute  the  epipodialia ;  the  bones  of  the 
carpus  and  tarsus  are  mesopodialia ;  the  metacarpalia  and  metatarsalia  are — as  indeed 
they  have  previously  been  called — the  metapodialia,  and  the  old  term  phalanges  is 
retained  for  the  bones  of  the  digits  and  dactyls. 

§  84.  Carpus  and  Tarsus. — The  carpalia  (bones  of  the  carpus),  and 
the  tarsalia  (bones  of  the  tarsus),  are  variously  interpreted  by  different 
writers ;  see  Balfour,  A,  II,  508. 

The  following  general  description,  based  chiefly  upon  the  researches  of 
Gegenbaur,  is  given  by  Huxley,  A,  31  :  — 

'^  There  is  reason  to  believe  that,  when  least  modified,  the  carpus  and 
the  tarsus  are  composed  of  skeletal  elements  which  are  alike  in  number  and 
arrangement. 

"  One  of  these,  primitively  situated  in  the  centre  of  the  carpus  or  tarsus, 
is  termed  the  centrale  ;  on  the  distal  side  of  this  are  five  carpalia,  or  tarsalia, 
which  articulate  with  the  several  metacarpal  or  metatarsal  bones ;  while,  on 
its  proximal  side  are  three  bones — one  radiale  or  tiUale,  articulating  with 
the  radius  or  tibia  ;  one  ulnare  or  fibulare,  with  the  ulna  or  fibula ;  and  one 
intermedium,  situated  between  the  foregoing. 

"  Carpal  and  tarsal  bones  or  cartilages,  thus  disposed,  are  to  be  met  with 
in  some  Amphibia  and  Chelonia,  but,  commonly,  the  typical  arrangement  is 
disturbed  by  the  suppression  of  some  of  these  elements,  or  their  coalescence 
with  one  another. 

"Thus,  in  the  carpus  of  man,  the  radiale,  intermedium,  and  ulnare  are 
represented  by  the  scaphoides,  lunare,  and  cuneiforme  respectively.  The 
pisiforme  is  a  sesamoid  bone,  developed  in  the  tendon  of  the  M.  flexor  carpi 
ulnaris,  which  has  nothing  to  do  with  the  primitive  carpus.  The  centrale 
is  not  represented  in  a  distinct  shape,  having  probably  coalesced  with  one  of 
the  other  elements  of  the  carpus.  The  fourth  and  fifth  carpalia  have 
coalesced,  and  form  the  single  unciforme.     See  §  421. 

*^In  the  tarsus  of  man  the  astragalus  represents  the  coalesced  tibiale  and 
intermedium  ;  the  calcaneum.  the  fibulare.  The  naviculare  {scaphoides  of 
Anthropotomy)  is  the  centrale.  Like  the  corresponding-  bones  in  the 
carpus,  the  fourth  and  fifth  tarsalia  have  coalesced  to  form  the  cuhoides.^^ 

§  85.  In  the  cat,  so  far  as  we  can  judge  from  the  figures  and  statements 
of  Flower  (36,  138),  and  Mivart  (B,  96,  Fig.  60),  and  from  our  own 
observations,  the  condition  of  things  is  as  follows  : — 

In  the  tarsus,  aside  from  peculiarities  of  shape,  the  tarsalia  and  their 
connections  are  as  in  man. 

In  the  carpus,  the  same  is  the  case,  excepting  that  the  scapho-lunare 
represents  not  only  the  scaphoides  and  the  lunare — the  radiale  and  inter- 
medium of   the  primitive   carpus — but  also  the  centrale.      Flower  found 


42  INTR  OD  UCTION. 

this  element  distinct  in  a  dog ;  the  senior  author  has  observed  (19,  301, 
Fig.  1,)  it  as  a  separate  center  of  ossification  in  a  young  lion,  shown  in 
Figure  47 ;  and  it  is  apparently  shown,  though  not  alluded  to,  by  Mivart, 
(B,  Fig.  60.) 

There  are  many  interesting  and  important  questions  connected  with  the  composition 
of  the  carpus  and  tarsus  of  different  Vertebrates,  and  those  interested  in  the  subject 
may  consult  Gegenbaur  (Lankester),  A,  479-481,  487,  488,  and  the  papers  of  that  anato- 
mist, Morse  (18  and  1)  Marsh  {1),  and  Wilder  {10). 

§  86.  The  metapodials  are  comparatively  simple  elements.  In  the 
diagram,  the  pollical  (first)  metacarpal  is  made  shorter  than  the  rest,  as  is 
the  case  in  the  cat,  and  the  primal  (first)  metatarsal  is  represented  as  a  slight 
rudiment,  the  remainder  of  it  and  the  whole  dactyl  being  absent,  and  hence 
shown  by  dotted  lines. 

The  ordinary  digits  and  dactyls  have  each  three  phalangeal  segments, 
proximal,  intermediate,  and  distal.  The  pollex  has  but  two,  and  in  those 
Mammals  which  have  a  primus,  this  usually  consists  of  but  two  phalanges. 

§  87.  This  peculiarity  of  the  pollex  and  primas  has  always  constituted  a  main  argu- 
ment in  favor  of  the  prevailing  view  as  to  the  correspondence  of  the  limbs  with  each 
other — inter m enibi^al  h omology. 

According  to  this  view,  the  cephalic  borders  of  the  arm  and  leg  correspond,  raorphi- 
cally  as  well  as  telically ;  the  radius  is  the  homologue  of  the  tibia,  and  the  ulna  of  the 
fibula  ;  and  the  pollex  is  both  the  homologue  and  the  analogue  of  the  primus. 

This,  the  syntropical  idea  of  intermembral  homologies,  has  been  adopted,  in  one  form 
or  another,  by  nearly  all  anatomists. 

The  other  idea,  that  of  antitropy,  has  been  advocated  or  accepted  by  a  much  smaller 
number,  including  the  elder  Agassiz,  Coues,  Dana,  Foltz,  Wyman,  and  the  senior  author. 

According  to  this  view,  the  two  ends  of  the  soma,  and  thus  the  cephalic  and  caudal 
aspects  of  the  limbs,  are  reversed  or  symmetrical  repetitions  of  one  another,  as  are  the  cor- 
responding organs  upon  the  right  and  left  sides.  The  radius  thus  becomes  the  homologue 
of  the  fibula,  and  the  tibia  of  the  ulna,  while  the  pollex  represents  the  quintus,  and  the 
minimus  the  primus. 

Fully  recognizing  the  apparent  objections  to  this  view,  we  nevertheless  believe  it  to 
be  correct,  and  would  refer  those  interested  in  the  subject  to  the  paper  (10)  by  the  senior 
author,  where  these  objections  are  discussed  and  the  opinions  of  other  writers  stated, 
with  a  List  of  Works  and  Papers  treating  of  the  general  question. 

§  88.  Enumeration  of  Parts  in  a  Series.— As  has  been  stated  (§  30, 
79),  two  or  more  similar  parts  which  form  a  series  are  enumerated  in  order, 
beginning  with  the  one  nearest  the  head,  or  the  meson,  or  the  proximal  end 
of  the  more  comprehensive  part  of  which  they  are  subdivisions. 

On  the  diagram  (Fig.  6)  are  given  some  illustrations  of  this  method. 
The  vertebrae  have  been  referred  to  already.  Of  the  digits  and  dactyls,  the 
most  cephalic  in  each  series  may  be  designated  as  the  first ;  but  it  is  evident 
that  this  might  cause  confusion  in  the  case  of  animals  having  only  four 
or  a  less  number  of  fingers  or  toes. 


TRANSECTION    OF   A    3IAMMAL, 


43 


It  is  often  desirable  to  describe  the  place  of  origin  or  insertion  of  muscles 
as  from  or  upon  a  given  fraction  of  the  entire  length  of  a  long  bone.  When 
the  area  extends  over  a  third  of  the  whole  length  the  thirds  would  be 
designated  usually  as  proximal,  middle  or  distal;  but  when  fourths  or 
smaller  subdivisions  are  employed,  they  may  be  designated  as  first,  second, 
etc.,  as  shown  upon  the  femur  in  Fig.  G. 


Dorsal  aspect 


nzuralis 

ta 
-  a  ortau 


.OtScphaQVLS 

.Trachea 

.puLmo  (Lang)  dexter 


\   carpaUa 
''VnetacarpaU 
'^phaLanoes 


•Sternum 


..septum, 
ynedia 


^f^\{^t 


Ventral  aspect 


carpus  ^^ 


Fig.  7.— Diagram  op  an  Ideal  Transection  of  the  Thorax  op  the  Cat,  with 
THE  Arms  in  an  Approximately  Normal  Position,  and  showing  the 
Location  op  the  Principal  Viscera. 


§  89.  In  Fig.  7,  the  cut  surface  is  viewed  from  the  caudal  aspect,  so  that 
the  right  and  left  parts  are  as  in  the  other  diagram  (Fig.  6). 

As  a  whole,  the  body  is  symmetrical,  the  two  halves  being  reversed  repe- 
titions of  one  another  on  opposite  sides  of  the  meson. 

No  definite  separation  exists  between  the  dorsal  and  the  ventral  regions. 
We  may,  however,  speak  of  the  dorsal  and  the  ventral  aspects,  and  the 
vertebral  column,  or  main  axis  of  the  soma,  intervenes  between  the  dorsal 
cavity,  or  Canalis  neuralis,  and  the  ventral  cavity,  the  coelum,  whose  more 
cephalic  division  or  thorax  is  here  transected. 

The  Canalis  neuralis  contains  the  myelon,  and  the  coelum  the  organs  of 
organic  life,  the  thoracic,  abdominal  and  pelvic  ^viscera. 

The  following  parts  and  organs  are  mesal  or  approximately  so,  at  least 
in  the  embryo :  nose,  tongue,  myelon,  centra  vertehrarum,  aorta,  oesophagus, 
trachea,  heart,  sternum. 

The  following  are  in  pairs:  eyes,  ears,  kidneys,  costce,  costicartilagines 
(costal  cartilages),  pulmones  (lungs),  pleurce,  limbs. 

The  right  lung  is  shown  as  a  single  and  simple  sack,  communicating 


44  INTRODUCTION. 

with  the  trachea.  The  left  lung  is  reduced  to  give  place  for  the  names  of 
the  cavity. 

Each  pleura  is  seen  to  be  a  closed  sack,  which  lines  the  corresponding 
side  of  the  thorax  to  form  the  ectal  or  parietal  lamina,  and  is  reflected  upon 
the  viscera  to  form  the  ental  or  visceral  lamma.  Between  the  heart  and 
the  sternum,  on  the  meson,  the  two  pleurae  are  in  contact,  and  form  the 
septum  mediastinale. 

For  the  sake  of  simplicity,  the  pericardium  is  omitted,  and  the  heart 
shown  as  a  single  cavity  with  regular  walls.  The  single  vessel  emerging 
from  the  heart  will  be  referred  to  in  §  91. 

The  spaces  on  either  side,  between  the  skin  and  the  osseous  walls  of  the 
coelum  and  Oanalis  neuralis  are  occupied  by  the  muscles,  etc. 

The  arms  have  their  elbows  directed  dorsad,  and  the  palms  ventrad. 
The  caudal  aspect  is  seen,  the  bones  including  the  ulna  and  the  ulnare  (un- 
ciforme),  and  the  minimal  metacarpal  and  phalanges. 

§  90.  Relative  Positions. — The  letters  A-L  are  introduced  into  the 
diagram  for  the  sake  of  illustrating  certain  common  cases  of  designation  of 
relative  position. 

The  point  A  is  at  the  meson  on  the  dorsal  aspect  of  the  body  ;  its  posi- 
tion may  be  described  as  dorsimesal.  B,  C,  and  D  are  lateral  in  position, 
or,  to  be  more  specific,  sinistral. 

Relatively,  B  is  laterad  of  A,  while  C  is  dorsad  of  D.  Since  they  are 
upon  a  curved  surface,  B  may  be  described  as  either  dorsad  or  mesad  of  C  ; 
while  C  may  be  said  to  lie  either  ventrad  or  laterad  of  B.  Which  expres- 
sion should  be  employed  would  depend  upon  the  context ;  in  either  case, 
practically,  there  is  no  room  for  ambiguity. 

Ectal  and  Ental. — Of  the  three  planes  represented  by  0,  E,  F,  the 
former  is  relatively  ectal,  the  last  is  ental,  and  the  third  intermediate. 

Proximal  and  Distal. — G  is  at  the  proximal  end  of  the  humerus,  and 
H  at  the  distal  end.     G  is  thus  proximad  of  H,  and  H  distad  of  G. 

Central  and  Peripheral. — On  the  artery,  I  is  centrad  of  K,  and  K  is 
peripheral  in  comparison  with  I,  but  centrad  of  L. 

On  the  nerve  which  leaves  the  myelon,  M  and  N  are  relatively  central 
and  peripheral. 

§  91.  Use  of  some  Terms  of  Relative  Position  in  a  Physiological 
Sense. — Central  and  peripheral,  and  sometimes  other  terms  are  employed 
in  a  physiological  rather  than  in  a  strictly  topographical  sense. 

For  example,  on  the  nerve  the  ventral  curve  is  really,  that  is  topographi- 
cally, nearer  the  myelon  and  the  meson  than  N  ;  but  N  w^ould  nevertheless 
commonly  be  described  as  centrad  of  the  curve. 

A  striking  case  of  this  sort  is  furnished  by  the  recurrent  laryngeal  hranch  of  the  N. 
vagus.  In  a  part  of  its  course,  it  curves  around  one  of  the  great  arteries  near  the  heart, 
and  then  passes  cephalad  to  the  larynx.     Now  the  larynx  is  much  nearer  the  brain,  where 


THE    SLIP-SYSTEM.  45 

the  N.  vagus  arises,  than  is  the  heart ;  topographically,  therefore,  the  termination  of  the 
nerve  is  nearer  the  brain  than  part  of  its  trunk  ;  yet  the  termination  would  be  described 
as  the  peripheral  portion. 

On  the  artery  shown  in  Fig.  7,  ventrad  of  the  bones  of  the  left  arm,  K 
is  peripherad  of  I,  and  L  of  K.  If  the  arm  should  be  so  flexed  as  to  bring 
the  artery  into  the  position  of  the  dotted  lines,  L'  would  be  topographically 
nearer  the  heart  than  K,  but  would  nevertheless  be  a  peripheral  point  on  the 
vessel. 

A  somewhat  similar  case  is  offered  by  the  abdominal  portion  of  the  ali- 
mentary canal  as  shown  on  Fig.  6.  In  the  strict  topographical  sense,  the 
ccBCum  and  contiguous  portion  of  the  small  intestine  lie  caudad  of  the  colon. 
In  some  cases,  a  description  would  refer  to  this  fact,  but  it  would  be  never- 
theless understood  that,  physiologically  and  in  respect  to  the  course  of  the 
contents  of  the  canal^  the  caecum  is  intermediate  between  the  small  intes- 
tine and  the  colon,  and  is  therefore  caudad  of  the  one  and  cephalad  of  the 
other.  The  relation  in  the  one  case  is  merely  of  contiguity  ;  in  the  other, 
of  structural  and  functional  continuity. 


v.— THE   SLIP-SYSTEM   OF  NOTES. 

§  92.  The  following  suggestions  as  to  "  notes  "  are  here  introduced  not  because,  like 
the  foregoing  matters,  they  render  what  follows  more  intelligible  or  available,  but 
because,  taking  for  granted  that  none  will  have  got  so  far  in  the  volume  without  the 
intention  to  do  some  serious  scientific  or  literary  work,  we  desire  to  put  them  in  possession 
of  a  method  which  has  proved  most  useful  to  us,  and  which  we  shall  be  glad  to  have 
adopted  by  our  readers  even  if  their  only  employment  of  it  is  in  recording  criticisms  of  our 
statements  and  ideas. 

§  93.  The  essential  feature  of  a  "  slip-system "  is  the  use  of  separate 
slips  of  uniform  and  convenient  size. 

Accessory  features  concern  the  precise  size  and  form,  of  the  slips,  the  way 
of  writing  upon  them,  and  the  manner  of  their  filing  and  distribution  for 
reference. 

§  94.  After  constant  use  of  the  slips  for  fifteen  and  seven  years  respec- 
tively, we  make  the  following  specific  recommendations  :  — 

§  95.  The  Slips. — Excluding  those  used  in  the  Catalogues  of  Libraries 
and  Museums  (which  will  be  referred  to  farther  on)  the  note-slips  should 
be  of  unruled  paper;  white,  blue,  light  broiun  or  yelloiv  in  color  ;  slightly 
sized,  so  as  to  take  either  the  pencil  or  the  pen  ;  moderately  stiff,  but  not 
thick  ;  and  of  the  size  of  the  U,  8.  Postal  Card,  at  present  13  x  7.7  cm. 

§  96.  Making  Notes. — Some  of  these  slips  should  be  carried  in  the 
pocket  at  all  times,  preferably  in  the  pocket-book,  which  is  usually  large 
enough  for  folded  letters. 


46  INTR  OB  UCTION. 

Temporary  memoranda  may  be  made  across  the  slip,  but  all  other  notes 
should  be  written  lengtlucise,  and  preferably  on  one  side  only. 

§  97.  Slip  notes  are  of  the  following  kinds:  museum  catalogues;  library 
catalogues  ;  references  ;  extracts  ;  clippings  ;  statements  of  observations  or 
ideas,  original  or  otherwise,  with  or  without  drawings. 

§  98.  Library  Catalogues. — The  titles  of  books  and  papers  should 
comprise  at  least  the  following  data  :  the  author's  name  and  surname  or 
initials  ;  the  title  and  subtitle  of  the  book  or  paper.  With  a  hooh^  the  edi- 
tion, size,  number  of  pages  and  illustrations  ;  the  place  and  date  of  publica- 
tion. With  a  paper,  the  Periodical  in  which  it  was  first  published,  dates  of 
presentation  and  publication,  the  volume,  part,  pages  and  illustrations.  With 
both,  references  to  Translations  and  Abstracts. 

The  foregoing  data  are  entered  in  various  orders,  and  with  different  kinds 
of  abbreviation.  Those  who  desire  to  adopt  some  standard  method  of  writ- 
ing titles  should  consult  the  ^'  Catalogue  of  Scientific  Papers  "  published  by 
the  Eoyal  Society  of  London,  the  publications  of  "  The  American  Library 
Association,"  and  the  "List  of  Periodicals  taken  by  the  Public  Libraries 
near  Boston." 

A.  One  of  the  valuable  suggestions  of  the  Library  Association  is  that  the  more  com- 
mon given  names  should  always  be  indicated  by  the  initial,  this  initial  being  distinguished 
from  the  same  letters  used  elsewhere  by  a  colon  following :  For  example,  E.  might  stand 
for  Edwin,  Egbert,  Edmund,  etc.,  but  E:  would  always  signify  Edward. 

B,  Another  suggestion,  that  the  sizes  of  books  should  be  indicated  not  by  numbers 
but  by  the  initials  of  the  words  signified  by  the  numbers,  as  0.  for  octavo,  etc.,  is  carried 
out  in  the  "List"  just  mentioned,  and  is  made  more  available  by  the  use  of  the  "Book 
Size  Rule,"  provided  by  the  Readers  and  Writers  Economy  Company,  being  a  metric 
rule,  30  cm.  (1  ft. )  long  ;  this  is  also  a  convenient  desk  rule. 

§  99.  Catalogue  Data. — On  the  face  of  the  Museum  Catalogue  Card 
should  be  noted  the  following  :  Museum  number,  original  number,  class  (of 
animals),  series  (of  specimens  or  preparations),  genus,  species,  common  name, 
locality,  sex,  age,  dates  of  collection,  death,  and  reception  (which  do  not 
always  coincide).  This  should  leave  the  lower  half  of  the  face  for  a  brief 
description  of  the  preparation  ;  purpose  for  which  it  was  made  ;  reference  to 
any  original  list,  to  publications,  etc. 

On  the  reverse  of  the  slip  should  be,  after  a  repetition  of  the  museumr 
number :  the  original  weight  of  the  brain,  and  of  the  body,  and  the  ratio  in 
decimals;  the  present  (usually  alcoholic)  weight  of  the  brain  and  body;  the 
capacity  (of  an  inflated  preparation);  the  length  from  vertex  to  anus  (of  an 
entire  example);  by  whom  collected  ;  when  and  by  whom  prepared  ;  donor 
or  seller;  his  address;  original  cost,  expressage,  etc.,  hours'  work;  estimated 
present  value ;  museum  numbers  of  other  specimens  from  the  same  indi- 
vidual ;  numbers  of  other  preparations  from  members  of  the  same  Utter; 
numbers  of  other  specimens  with  which  this  may  be  instructively  compared. 


HOW    TO     TAKE    NOTES.  47 

With  care  in  the  arrangement  and  abbreviation  of  these  points,  all  may  be  entered, 
together  with  others  not  here  specified.  We  have  not  yet  fully  determined  upon  the 
best  form  for  the  Catalogue  slip,  and  hope  others  will  offer  the  results  of  their  experience. 

For  library  and  museum  catalogues,  the  slips  should  be  of  heavier  and  stiffer  paper 
than  for  ordinary  notes,  and  the  surface  should  be  well-sized,  since  ink  is  commonly 
employed. 

§  100.  References. — The  slips  may  be  used  for  brief  references  to 
works,  papers,  persons,  addresses,  localities,  museums,  etc.,  constituting,  in 
fact,  permanent  memoranda,  which  may  be  filed  with  more  elaborate  or 
extended  materials  upon  the  same  subjects. 

§  101.  Extracts. — Upon  one  side  of  the  slip  may  be  written  from  40  to 
50  words,  either  by  hand,  or  with  the  type-writer  when  the  lines  are  at 
medium  distance,  1  cm.  apart.  At  short  distance,  the  number  is  just 
doubled,  and,  if  necessary,  both  sides  may  be  written  on,  or  two  or  more  slips 
may  be  used,  or  a  sheet  may  be  used,  and  then  folded  to  the  slip  size. 

§  102.  Clippings. — Clippings  from  periodicals  and  newspapers  may 
often  be  accommodated  upon  the  slip.  When  no  longer  than  the  slip  is 
wide,  they  may  be  pasted  at  either  end,  with  the  lines  always  lengthwise  of 
the  slip.  When  the  length  is  greater  than  the  width  of  the  slip,  the  columns, 
if  narrow,  may  be  pasted  side  by  side  ;  but  usually  so  much  as  exceeds  the 
width  must  be  pasted  on  the  remaining  space  so  that  the  lines  run  across  the 
slip.  By  thus  covering  both  sides,  a  single  slip  may  receive  an  entire  column 
of  "The  Medical  Record,"  or  ^^ Science;"  more  than  half  a  column  of 
"  The  Nation,"  and  nearly  half  a  column  of  the  "  New  York  Daily  Tribune." 

Even  when  unaccompanied  by  the  signature  of  some  well-established 
authority,  such  clippings  serve  as  memoranda  which  may  aid  in  looking  up 
the  matter  farther,  and  as  more  or  less  valuable  confirmatory  evidence. 

§  103.  Notes  Proper. — The  most  common  and  most  important  use  of 
the  slips  is  as  a  ready  and  convenient  vehicle  for  the  many  kinds  of  informa- 
tion which  the  scientific  or  literary  worker  desires  to  record  and  to  use. 

The  Slip  is  Alivays  at  Hand. — It  may  be  written  upon  without 
parade,  and  under  almost  any  circumstances,  whether  sitting  at  the  table,  or 
riding  in  the  cars,  or  even  on  horseback ;  whether  engaged  in  regular 
work,  or  conversing  with  friends,  or  even  at  night  and  in  the  darkness. 
Under  all  these  conditions,  more  or  less  favorable,  the  essence  or  "  pith  "  of 
a  fact  or  idea  may  be  recorded,  though  sometimes  in  a  shape  quite  unintel- 
ligible to  others  and  well-nigh  so  to  the  writer,  unless  an  early  opportunity 
is  taken  for  putting  it  in  better  form. 

§  104.  Accumulation  and  Elimination  of  Slips.— -The  beginner's 
object  is  to  accumulate  the  brief  records  of  what  he  has  learned,  but  is  not 
sure  of  remembering  when  wanted. 

After  the  first  year,  however,  many  of  the  things  thus  recorded  become 
familiar  as  the  alphabet,  and  much  also  that  is  supposed  true  to-day  may  be 


48  INTRODUCTION. 

disproved  to-morrow,  or  superseded  by  more  accurate  descriptions,  more 
perfect  drawings,  and  more  logical  discussions. 

With  the  ordinary  note-book,  or  Index  Eerum,  all  these  untruths, 
half-truths,  or  truisms  must  forever  remain  where  they  were  placed.  From 
being  merely  superfluous,  they  soon  become  burdensome,  then  confusing,  and 
finally  a  source  of  loss  and  exasperation. 

Not  so  the  slip  ;  the  instant  its  usefulness  is  at  an  end,  into  the  waste- 
basket  it  goes,  making  room  for  more  desirable  successors. 

§  105.  Arrangement  and  Storage  of  Notes. — After  trying  many 
different  plans,  we  make  the  following  practical  suggestions  : — 

§  106.  Slip- Portfolios.'^ — The  slip-portfolio  is  for  holding  the  notes 
upon  a  given  subject. 

It  is  made  from  a  piece  of  stiff  Manilla  paper,  16  x  13  cm.,  and  folded  over 
a  pencil  so  that  the  folded  edge  is  left  rounded.  The  slips  are  introduced, 
the  title  of  the  subject  is  written  along  the  top,  and  tlie  whole  is  bound 
together  by  a  rubber  band  7  cm.  long  by  1  mm.  thick,  like  No.  372  of  the 
Price-list  of  the  R.  and  W.  Ec.  Co. 

Such  a  portfolio  will  hold  50  slips,  but  usually  when  there  are  more  than 
25  they  should  be  subdivided. 

§  107.  Subdivision  of  Notes. — Let  us  suppose  that  the  student  is 
collecting  information  respecting  the  heart  of  the  cat.  While  his  notes  are 
few^,  all  may  be  contained  in  a  single  portfolio.  As  they  multiply,  they 
naturally  fall  into  four  categories  relating  respectively  to  the  structure  of 
the  organ,  \i^  functions,  its  development,  and  the  titles  of  works  and  papers 
treating  of  it.  As  the  notes  increase  under  each  of  these  heads,  anatomical 
notes  may  be  divided  naturally  into  sets  relating  respectively  to  the  appear- 
ances  which  are  visible  to  the  eye,  those  which  require  the  aid  of  the  micro- 
scope, and  those  which  involve  special  kinds  of  manipulation,  as  boiling,  etc., 
in  order  to  display  the  arrangement  of  the  fibers.  The  macroscopic  anatomy 
may  refer  to  the  auricles,  the  ventricles  or  the  valves,  and  each  of  these 
headings  may  be  still  further  subdivided. 

We  see,  therefore,  that  without  the  subdivision  of  the  notes  upon  five 
quite  extensive  topics,  the  heart  might  require  the  use  of  a  dozen  separate 
portfolios.  Since  all  of  these  concern  the  heart,  they  may  all  be  bound 
together  by  a  stronger  band,  say  No.  385,  8  cm.  long  and  3  mm.  wide  ;  or, 
they  might  be  bound  in  two  sets,  the  one  including  all  the  divisions  of  the 
gross  anatomy,  and  the  other  the  rest. 

Such  a  plan  of  subdivision  is  not  only  convenient  for  reference,  but 
furnishes  an  exercise  in  Natural  Classification  ;  see  p.  49,  §  108. 

§  109.     Distribution. — Since  it  is  not  always  convenient  to  assign  the 

*  The  employment  of  the  portfolios  was  suggested  to  us  by  Wm.  Nichols,  M.D.,  of 
Boston,  Mass. 


SUBDIVISION    OF   NOTES, 


49 


—     1-t 


I 


I 
I 


s 


< 
u 

o 


< 


50 


INTRODUCTION. 


notes  to  their  proper  places  at  the  time  they  are  made,  it  is  well  to  have  an 
extra  portfolio,  which,  in  this  case,  would  be  marked,  ''  Heart  of  Cat ; 
Distribution." 

When  its  contents  are  to  be  distributed,  the  other  portfolios  are  arranged 
upon  the  table  in  some  natural  order ;  the  removal  of  their  bands  will 
permit  the  upspringing  of  the  side  so  as  to  expose  the  heading,  and  facilitate 
the  introduction  of  shps. 

§  110.  Slip-box.— This  should  be  of  stout  tin,  preferably  Japanned. 
The  inside  measures  of  length  and  width  should  be  22  cm.  x  14  cm.  (about 
9  X  5.5  in.),  which  is  nearly  the  size  of  the  ordinary  sheet  of  note  paper. 

The  depth  is  less  simply  stated.  If  the  box  has  a  folding  lid,  like  the 
'^Japanned  tray,  postal  size,"  here  figured  (Fig.  8),  a  depth  of  8  cm.  will  be 
needed.  But  the  scientific  student  has  such  abundant  need  for  shallow 
trays,  that  he  will  usually  find  it  more  convenient  to  have,  in  place  of  the 
folding  lid,  a  single  cover,  2  cm.  deep.  This  should  overlap  the  edge  of 
the  box  for  1  cm.,  resting  on  a  welt.  The  depth  of  the  box  itself  will  then 
be  only  7  cm. 

If  the  slips  are  kept  in  envelopes  instead  of  portfolios,  the  box  and 
cover  together  should  have  a  depth  of  9  cm.  The  Japanned  tray,  "  standard 
size,"  is  only  5  cm.  deep,  and  if  the  "postal  size  "  is  ordered,  care  should  be 
taken  that  it  is  of  the  actual  width  required  for  the  postal  qard,  since  some 
the  of  so-called  ^'postal  slips  "  are  only  12.5  cm.  long. 

The  free  edges  of  the  box  and  cover  should  be  turned,  and  the  latter 
should  be  "soldered." 

§  111.  Cost  of  Materials. — The  tin  box  may  be  had  for  from  50  cents  to  $1.00.  A 
\:n  cash-box,  with  lock,  costs  $1.50.  The  Japanned  tray,  postal  size,  with  slips,  blocks 
and  cruides,  costs  $3.65. 

"  Roll  Manilla,"  40  inches  wide,  is  8  cts.  per  yard ;  including  the  cutting,  the  slip- 
folios  cost  at  the  rate  of  10  cts.  for  25-35. 

The  bands  are  rated  at  $2.20  per  M.  for  No.  372,  and  $5.85  for  No.  385.  By  the  hun- 
dred they  cost  proportionally  a  little  more. 

The  slips  may  be  cut  by  hand,  but  it  is 
usually  cheaper  to  have  the  cutting  done 
by  the  stationer.  They  cost  from  50  cts. 
to  ^1.00  per  M. 

§  112.  Other  Methods.— The  slips 
may  be  placed  in  envelopes,  sealed  at  the 
node,  and  with  the  right  end  cut  off.  If 
this  plan  is  adopted,  it  is  true  economy  to 
use  stout  envelopes  which  will  not  readily 
fray  and  tear.  Cloth-lined  envelopes  of 
the  proper  width,  9  cm.  (three  and  one-half 
inches),  may  be  had  for  about  $2  50  licr 
hundred,  and  are  practically  indestructible. 

Another  way  is  to  write  the  heading 
upon  a  card  the  size  of  the  slips,  and  put 


Fig.  8.— The  Japanned  Tkay,  fob  Cata- 
logue Slips.  Readeks  and  Writers 
Economy  Company. 


PREPARATION    OF   MANUSCRIPT,  51 

the  band  over  all.     Finally,  there  is  the  method  exemplified  by  the  accompanying  figure 
(Fig.  8),  which  seems,  however,  better  adapted  for  museum  and  library  catalogues. 

§  113.  Using  the  Slips. — For  ordinary  reference,  the  portfolio  is  held 
in  the  left  hand,  the  band  removed,  and  the  slips  turned  until  the  desired 
one  is  found. 

As  a  basis  for  manuscript  or  lecture-notes,  they  may  be  arranged  in  the 
proper  order  by  spreading  them  out  upon  the  table  ;  more  or  less  condensa- 
tion and  elimination  will  then  occur.  The  selected  or  condensed  notes  may 
be  used  as  lecture-notes,  or  their  substance  transcribed  to  sheets. 

§  114.  For  carefully  prepared  manuscript,  the  following  stages  of  com- 
position are  recommended  : — 

1.  Slips,  hand-written.  2.  Slips,  selected,  condensed,  and,  if  possible, 
type-written.  3.  Sheets,  hand  or  type-written,  into  which  the  type-written 
slips  may  sometimes  be  incorporated  by  pasting.  4.  Sheets,  carefully  type- 
written, a  corrected  copy  of  the  first  set. 

Manuscript  so  prepared,  especially  if  in  addition  an  interval  of  at  least 
one  week  elapses  between  the  first  and  the  second  copies,  will  usually  need 
few  changes  in  proof. 

§  115.  Sheet-Portfolios. — The  sheets  referred  to  are  of  the  standard 
note  size,  about  21  x  12.5  cm.  Such 
sheets  and  drawings  of  similar  size  may 
be  conveniently  kept  in  sheet-portfolios  of 
the  Manilla  paper,  double  the  size  of  the 
sheet,  say  about  21  x  27  cm. 

Portfolios  of  sheets,  or  the  sheets 
themselves,  may  he  conveniently  kept  in 
the    "Pigeon    Hole    Case,"    "pamphlet 

size,"  supplied  at  11.50  by  the  R  &  W. 

-r,      n        mi                  1             •      4-1,     ^  1^^-  9. — Uniform,  interchange- 

Ec.  Co.     The  case  shown  m  the  fissure  ^          tt       ^ 

_,.„   ,       .      „     °„  ABLE  Pigeon  Hole  Case,  Billet 

js    known    as   the    "Billet    size."      For  ^^^^    Readers  &  Writers  Eco- 

"  note  sheets,"  there  are  only  two  tiers  of  nomy  Co.,  (A.) 
holes. 

§  116.  Miscellaneous  Suggestions.— A.  Bj  writing  the  portfolio  headings  with 
pencil,  they  may  be  changed  as  desired,  and  to  any  extent.  Even  if  written  with  ink  or 
printed,  however,  each  portfolio  presents  four  surfaces  which  may  be  used  in  turn. 

§  117.  B.  The  type-writer  or  calligraph  can  be  adjusted  to  any  width  of  paper.  Of 
course,  the  longer  the  line  the  fewer  the  shiftings  ;  but  the  narrower  sheet  is  more  easily 
manipulated,  especially  when  changes  or  divisions  are  required,  and  it  is  often  a  real  ad- 
vantage to  be  able,  without  delay,  to  write  alternately  upon  the  sheets  and  the  slips. 

§  118.  C.  While  assorting  a  large  number  of  slips  for  which  portfolios  have  not  been 
prepared,  it  is  sometimes  desirable  to  remove  them  all  without  mixing  the  separated  piles. 
This  may  be  accomplished,  either  by  interposing  a  blank  slip  between  the  successive  piles, 
tjf  by  placing  them  crosswise,  and  carrying  a  band  over  them  diagonally. 


t)'Z  INTRODUCTION. 

§  119.  Orig:in  of  the  Slip-system. — ^It  is  probable  that  the  slip-sjstem 
hiis  been  devised  independently  by  many  individuals,  and  we  are  informed 
ti)at  Mr.  Folsom,  the  Librarian  of  the  Boston  Athenaeum,  proposed  the  use 
of  slips  in  Card  Catalogues  at  the  Librarian's  Convention  in  New  York  in 
1852.  As  a  means  of  recording  and  arranging  scientific  information,  how- 
ever, the  first  published  notice  known  to  us  is  the  following  by  the  senior 
author  (17),  communicated  to  the  Boston  Society  of  Natural  History, 
May  15,  1867  :— 

§  130.  "  It  consists  in  the  brief  statement  of  facts,  ideas,  or  references 
to  books,  written  upon  one  side  of  a  slip  of  paper  equal  to  the  sixth  part  of 
a  sheet  of  note  paper. 

"A  few  of  these  blanks  are  carried  in  the  pocket,  and  advantag-e  is  thns  taken  of  op- 
portunities for  recording  and  preserving  information  which  the  time,  place,  or  state  of 
mind  would  not  permit  to  be  written  out  in  full,  or  which  might  be  forgotten  before  a 
fitting  opportunity  should  occur. 

"  These  slips  are  distributed  at  leisure  into  envelopes  bearing  the  title  of  the  subject. 

"By  keeping  the  slips  separate,  it  is  evident  that  an  indefinite  subdivision  of  each 
general  subject  can  be  made  by  simply  increasing  the  number  of  envelopes  and  redistri- 
buting the  slips. 

"  The  slips  may  be  used  either  for  simple  reference,  or,  if  in  preparation  of  a  lecture 
or  communication,  by  arranging  them  on  the  table  in  any  desired  order,  and  transcribing 
parts  of  them  in  the  form  of  notes  ;  while  for  a  written  paper  they  serve  to  indicate  the 
general  order  of  discussing  a  subject. 

*'  The  method  proposed  makes  sure  of  the  essential  fact  or  idea  in  a  brief  form,  and 
the  slips,  being  kept  separate  and  of  uniform  size,  may  easily  be  arranged,  carried  and 
arranged,  or  rearranged  in  any  order  at  any  time." 

This  plan  was  presented  in  a  lecture  at  the  session  of  the  Anderson  School  of  Natural 
History  on  Penikese  Island,  in  July  1873,  and,  according  to  a  report  in  the  N.  Y.  Tribune, 
"  was  almost  universally  and  immediately  adopted." 


§  121.    The   Use  of  Slips  in  Scientific  Correspondence.—The 

following  is  from  a  note  by  the  senior  author  in  "  Science,"  v.,  p.  44,  Jan. 
16,  1885  : 

During  last  summer  I  began  to  use  slips  in  another  way,  suggested,  perhaps,  by  the 
fact  that  postal -cards  referring  to  a  single  point  were  frequently  filed  with  the  slip- notes 
on  the  same  subject. 

As  compared  with  a  letter  in  the  usual  form,  such  correspondence- slips  present  the 
following  advantages  :  1,  Each  point  may  be  attended  to  by  the  sender  or  the  receiver 
independently  of  others  which  may  require  more  delay ;  2.  Without  transcription,  the 
slips  may  be  filed  with  others  on  the  same  subject ;  3.  The  same  slip,  with  or  without 
attachments,  may  be  sent  back  and  forth,  or  to  other  correspondents,  for  comment  or  in- 
quiry ;  4.  The  date  of  each  writing  may  be  affixed  by  hand  or  by  the  use  of  Perkins'  rub- 
ber stamps  or  other  mechanical  device ;  5.  If  written  closely  or  with  the  type-writer 
there  is  usually  ample  space,  not  only  for  the  original  note,  but  for  an  answer  to  it, 
if   it  was  an  inquiry;    a   second  slip  is  attached  if  necessary;    6.    It  is  convenient  to 


APHORISMS  OF  GENERAL  APPLICATION.  53 

keep  envelopes  already  addressed  to  those  with  whom  one  desires  to  communicate  fre- 
quently, to  insert  the  slips  when  written,  and  to  send  the  letters  as  occasions  arise. 

From  a  note  in  "  Science,"  v,,  p.  86,  Jan.  30, 1885,  by  Mr.  B.  Pickman  Mann,  it  appears 
that  he  had  used  slips  for  many  years,  and  that  they  had  been  employed  for  correspond- 
ence between  Dr.  George  Dlmmock,  himself  and  others. 


§  122.  Rules  and  Aphorisms  of  General  Application. 

"In  the  order  of  Nature,  doing  comes  before  thinking;  Art  before 
Science." — Joseph  Henri/  (Mayer,  1,  95). 

"  Personal  familiarity  alone  makes  knowledge  alive." — Philip  Gilbert 
Hamerton, 

*' Practice  the  utmost  rigidity  and  thoroughness  in  research,  without 
regard  to  time  consumed,  or  value  of  results." — Henry  James  Clark  {Pack- 
ard, 1 ), 

^'Lenteur  dans  la  marche;  aridite  dans  I'etude ;  solidite  dans  les  prin- 
cipes;  surete  dans  les  resultats;  ce  sont  \k  les  attributs  des  sciences  d'ob- 
eervation." — Bichat,  A,  i,  p.  v. 

Correct  methods  are  the  keys  of  knowledge. 

Whoever  has  learned  how  to  work  has  taken  a  long  step  toward  indepen- 
dence of  teachers  and  books. 

"The  method  may  determine  the  result." — Louis  Agassiz. 

*'If  researches  take  at  the  first  step  a  wrong  direction  they  diverge  the 
farther  from  the  truth  the  farther  they  are  followed." — Gahoriau. 

"It  is  often  as  if  the  truth  were  rather  whispered  than  spoken  by 
Nature." —  Oiuen. 

Accuracy  is  more  to  be  desired  than  speed. 

Books  may  be  consulted  in  haste,  but  Nature  demands  deliberation. 

Non-discrimination  is  no  proof  of  identity. 

Ignorance  of  a  specimen's  locality  may  cause  delay ;  an  error  respecting 
it  may  create  confusion. 

As  is  the  locality  to  an  individual,  so  is  the  individual  to  any  of  its  parts. 

*' There  is  so  close  a  solidarity  between  ourselves  and  the  animal  world 
that  our  inaccessible  inward  parts  may  be  supplemented  by  theirs.  *  *  *  A 
sheep's  heart  or  lungs  or  eye  must  not  be  confounded  with  those  of  man  ; 
but  so  far  as  the  comprehension  of  the  elementary  facts  of  the  physiology  of 
circulation  and  of  respiration  and  of  vision  goes,  the  one  furnishes  the 
needed  anatomical  data  as  well  as  the  other." — Huxley,  3. 

"  Carpenters  and  tailors  do  not  learn  their  trades  upon  rosewood  and 
cloth  of  gol^:'— Wilder,  2^  8. 

'•Felitomy  should  be  the  stepping-stone  to  anthropotomy." — Idem,  2^  6. 

"No  medical  student  should  be  allowed  to  dissect  the  human  cadaver 
until  he  has  familiarized  himself  with  the  anatomy  of  the  cat." — Gleven- 
ger,  i,  1. 


54  INTRODUCTION. 

He  who  can  skillfully  dissect  a  cat  will  find  little  difficulty  in  dissecting 
a  man. 

"Fiat  experimentum  in  corpore  yili." 

The  softer  the  parts,  the  harder  their  study. 

Soft  parts  are  perishable. 

Hurried  dissection  is  rarely  trustworthy. 

The  thorough  examination  of  soft  parts  can  be  made  only  under  one  or 
more  of  the  following  conditions  :  A.  Limitation  of  the  inquiry;  B.  Abun- 
dance of  material  ;  C.  Continuity  of  dissection  ;  D.  Co-operation  of  several 
dissectors ;  E.  Preservation  of  the  parts. 

Filth  and  bad  odors  cannot  always  be  avoided,  but  their  continuance  is 
rarely  necessary. 

Accurate  knowledge  of  a  few  things  is  better  than  vague  ideas  concern- 
ing many. 

First  expressions  are  rarely  correct  or  perfect. 

A  description  is  perfect  only  when  it  enables  one  who  has  never  seen  the 
object  to  form  a  correct  image  of  it. 


ANATOMICAL    TECHNOLOGY. 


INTRODUCTORY. 


§  123.  This  work  treats  mainly  of  the  Gross  Anatomy  of  certain 
portions  of  the  Domestic  Cat,  and  of  the  Methods  of  their  Examina- 
tion and  Preservation. 

Reasons  for  Selection  and  Preference. — There  shall  be  given 
here  a  condensed  statement  of  the  reasons  for  selecting  the  Cat,  for 
giving  almost  exclusive  attention  to  the  Cephalic  region  of  the  body, 
and  for  devoting  to  tlie  Brain  and  other  Viscera  a  relatively  large 
amount  of  space. 

§  124.  For  Selecting  the  Cat.— Three  things  are  to  be  learned  by 
the  student  of  Anatomy  and  Physiology,  whether  Human,  Veteri- 
nary or  Comparative  :  methods  of  manipulation ;  fundamental /ac^^ 
of  structure  and  function  ;  and  terms  of  expression. 

Most  of  the  methods  might  be  learned  upon  any  mammal,  but 
convenience  and  economy  are  consulted  by  the  use  of  one  wliich  is 
at  the  same  time  widely  distributed,  common,  easily  kept  in  con- 
finement, and  of  moderate  size  so  as  to  be  readily  manipulated  and 
cheaply  preserved. 

Methods  cannot  be  practised  without  some  knowledge  of  the 
nature,  location,  and  uses  of  the  parts  concerned  ;  and  the  record  or 
communication  of  results  involves  the  use  of  terms ;  hence  there  is 
effected  a  substantial  saving  of  time,  mental  effort  and  expense  by 
employing,  in  the  acquisition  of  methods,  a  form  anatomically  and 
physiologically  comparable  with  those  which  the  student  is  pre- 
paring himself  to  investigate. 

The  adult  human  subject  is  inconveniently  large,  not  always  easy  to  obtain,  and  often 
expensive  when  all  things  are  considered.     The  immature  individuals  (still-births)  which 


56  INTR  OD  UCTOB  F. 

may  sometimes  be  had,  lack  the  firmness  of  texture  which  is  desirable  for  the  examination 
of  certain  parts. 

The  veterinarian  is  especially  interested  in  the  horse  and  the  cow  ;  but  these  are  too 
large  and  costly  for  elementary  work  ;  in  less  degree,  the  sheep  and  the  pig  are  open  to 
the  same  objection. 

The  needs  of  the  comparative  anatomist  were  well  expressed  in  the  course  of  a  "  Labora- 
tory talk/'  by  the  late  Prof.  Jeffries  Wyman,  as  recorded  by  the  senior  author  {1i,  5) : — 

**  In  commenting  upon  the  unsatisfactory  nature  of  some  published  notes  of  dissec- 
tions, he  said  :  *  Much  of  this  is  due  to  the  lack  of  suitable  standards  for  comparison.  The 
human  body  is  not  a  suitable  standard  for  the  lower  vertebrates.  The  best  thing  any 
anatomist  can  do  is  to  prepare  complete  accounts  of  the  structure  of  a  few  forms,  each 
typical  of  some  large  group.  The  fowl  could  represent  the  birds,  and  the  eat  the  mammals. 
The  cat's  anatomy  should  be  done  first,  because  it  would  also  serve  as  an  introduction  to 
Human  Anatomy,  and  thus  become  an  important  aid  to  Medical  Education.' " 

Theoretically,  among  known  forms,  the  wants  of  the  comparative  anatomist  might  be 
more  fully  met  by  the  more  generalized  opossum  or  raccoon.  The  tiny  musk-deer  of  Java 
could  be  more  easily  dissected  and  preserved  than  most  of  our  hoofed  quadrupeds  ;  while  a 
medium  sized  monkey,  especially  after  some  confinement,  is  the  best  possible  substitute 
for  the  human  subject. 

Unfortunately,  however,  none  of  these  animals  is  suflBeiently  abundant  in  all  parts  of 
the  civilized  world,  and  we  must  select  such  as  are  to  be  had.  The  rat  is  certainly  too 
small  for  most  purposes,  and  not  easy  to  obtain  unmutilated.  The  rabbit,  like  the  rat, 
belongs  to  a  group  of  peculiar  mammals,  the  Rodents,  with  no  special  advantages  in 
respect  to  either  human  or  veterinary  anatomy.  Dogs  vary  greatly  in  size  and  mode  of 
life,  so  that  no  one  of  the  many  breeds  can  be  fairly  spoken  of  as  the  dog,  and  although, 
as  stated  by  the  senior  author  (21,  308),  the  pectoral  muscles  present  less  variation 
than  might  be  expected,  few  comparisons  have  been  made  of  the  other  soft  parts  except- 
ing the  brain,  where,  as  regards  the  disposition  of  the  cerebral  fissures,  the  variation  is 
considerable  and  perplexing  (Wilder,  12,  242). 

So  far  as  we  can  judge  from  published  records  and  our  own  observations,  cats  are  much 
less  subject  to  variation  than  dogs.  They  are  both  wndJcers  and  climbers,  and  therefore 
comparable  with  the  domestic  quadrupeds  on  the  one  hand,  and  with  the  monkeys,  and 
through  them  with  man,  on  the  other.  They  are  common  in  most  civilized  lands,  fertile, 
easily  reared,  and  may  be  kept  in  confinement,  even  in  considerable  numbers,  without 
diflSculty.  They  quickly  succumb  to  anaesthetics,  and  their  size  is  such  as  to  facilitate 
both  dissection  and  preservation  in  alcohol.     They  are  quiet,  while  dogs  are  noisy. 

§  125.  Of  a  less  practical  nature,  yet  well  worth  mention,  is  the  remarkable  combination 
in  the  cat's  organization,  of  delicacy,  agility  and  strength  ;  a  combination  which  seems 
almost  perfectly  adapted  to  the  prolongation  of  individual  life  and  the  perpetuation  of  the 
species.  Indeed,  as  well  remarked  by  Mivart  (B,  493,)  "Something  may  be  said  in  favor 
of  cats  being  the  highest  of  mammals,  if  man  is  considered  merely  in  his  animal  capacity, 
in  which  alone  he  can  be  brought  into  comparison  with  other  organisms."  See  also 
Minot,  1,  and  Dana,  123,  160. 

This  idea  will  be  acceptable  to  those  who  prefer  the  purely  teleological  aspect  of  Nature. 
Others,  however,  may  find  ample  ground  for  discussion  respecting  the  universal  operation 
of  the  doctrine  of  Final  Causes,  at  least  in  the  present  state  of  our  knowledge.  Teleology 
has  not  yet  explained  the  existence  of  the  insignificant  clavicle,  the  rudimentary  primal 
metacarpal,  the  little  pocket  at  the  border  of  the  ear,  or  the  cusps  on  the  deciduous  man- 
dibular canine  teeth. 

§  126.  In  short,  while  freely  conceding  the  advantages  which  might  be  presented  by 


INTRODUCTORY.  57 

other  forms,  especially  if  it  were  practicable  to  supply  a  separate  standard  for  the  anthro- 
potomist,  the  zoologist  and  the  veterinarian,  we  nevertheless  believe  that  even  then 
these  three  might  be  advantageously  compared  with  the  cat  as  a  fourth  and  intermediate 
form,  and  that,  when  all  points  are  considered — size,  habit,  distribution,  physical  endow- 
ment and  zoological  position — the  cat  should  be  chosen  over  all  others,  both  as  a  single 
standard  for  comparison,  and  as  a  subject  of  elementary  and  preliminary  anatomical  and 
physiological  work. 

§  127.  Nor  is  this  choice  wholly  without  precedent.  It  is  true  that  descriptive  and 
practical  works  upon  Mammals  have  been  more  often  based  upon  others  than  the  cat.  For 
obvious  reasons,  the  horse  has  been  the  subject  of  many  publications  ;  the  rabbit  is  selected 
by  Krause  (A),  the  rabbit  and  the  dog  by  Foster  and  Langley  (A),  the  rat  by  Rolleston 
(A)  and  Morrell  (A),  while  Coues  has  described  (47)  the  skeleton  and  muscles  of  the 
opossum. 

Yet  Straus  Durckheim  devoted  a  magnificent  monograph  to  the  bones,  ligaments  and 
muscles  of  the  cat  ;  and  reduced  copies  of  his  outline  plates,  with  a  translation  of  the 
"  Explanations,"  have  been  published  by  our  colleague,  Prof.  Henry  S.  Williams.  The 
skeleton  is  delineated  and  named,  in  connection  with  those  of  the  Duck  and  the  Codfish, 
by  E.  Tulley  Newton  (A),  and  as  the  work  was  "prepared  under  the  supervision  of 
Prof.  Huxley,"  the  usefulness  of  the  cat  has  probably  been  appreciated  by  that  zoologist. 
Finally,  the  recent  volume  by  Mivart  (B)  purports  to  describe  the  entire  structure  of 
the  cat,  although  no  practical  directions  are  given,  and,  according  to  notices  in  The  Nation 
for  June  3, 1881,  and  in  Science,  and  The  Athenoeum  for  June  4,  the  author  seems  to  have 
made  somewhat  frequent  and  wholly  unspecified  substitutions  of  human  anatomy  for  that 
of  the  cat. 

The  junior  author  has  published  two  papers  (i,  3)  upon  the  anatomy  of  the  cat ;  and 
the  desire  for  a  complete  account  of  its  brain,  expressed  by  the  senior  author  in  1873 
(11,  229),  has  been  recently,  in  part,  fulfilled  in  the  impers  numbered  2,  3,  4,  tT,  6*, 
7,  8,  9,  12,  13  and  14. 

§  128.  Reasons  for  Treating  of  only  Part  of  the  Body. — This 
work  is  primarily  an  explanation  of  methods,  and  the  descriptions 
of  organs  are  mainly  in  illustration  thereof. 

The  account  of  only  forty  muscles  covers  an  equal  number  of  pages.  To  devote  a  pro- 
portionate space  to  the  150  or  more  other  muscles,  and  to  all  the  arteries,  veins  and  nerves 
would  swell  the  volume  to  undesirable  dimensions.  Some  selection  was  therefore  neces- 
sary. 

Of  the  two  general  regions  of  the  body,  the  cephalic  is  certainly  more  familiar  to  most 
persons,  more  interesting,  more  employed  in  art,  more  often  used  in  experiment,  and  more 
subject  to  injury  and  disease.  To  obtain  and  prepare  the  heart  and  the  brain  involves 
some  manipulation  of  the  thorax  and  head. 

The  arm  of  the  cat  is  more  complete  than  the  leg,  since  it  has  all  five  of  the  digits, 
and  presents  the  interesting  and  important  provision  for  the  rotation  of  one  of  the  epipodial 
bones  about  the  other. 

Notwithstanding  our  doubts  respecting  the  homologies  of  the  M.  davo-trapezius  and 
some  of  the  antebrachial  muscles,  the  myology  of  the  arm  is  in  a  more  satisfactory  state 
than  that  of  the  leg,  where  the  great  "  adductors "  are  likely  to  puzzle  anatomists  for 
some  time  to  come. 

In  short,  the  same  practical  considerations  which  have  led  most  anatomists  to  describe 
the  muscles  of  the  antebrachium  with  more  fullness  than  those  of  the  back,  have  induced 
us  to  select  the  arm  rather  than  the  leg  for  the  more  detailed  descriptions. 


58  INTRODUCTORY, 

§  129.  Reasons  for  Giving  Unusual  Prominence  to  the  Vis- 
cera.— ^It  is  stated  by  Macalister  (British  Association  Report,  1877, 
p.  94),  that  ''at  least  600  bodies  are  annually  examined  in  the  dis- 
secting rooms  of  Great  Britain  and  Ireland;"  yet  how  few  are 
the  published  observations  respecting  the  characters,  constant  or 
variable,  of  any  parts  other  than  the  bones  and  the  muscles.  In 
this  country  the  case  is  still  worse,  and  we  have  no  journal  espe- 
cially devoted  to  Anatomy  and  Physiology. 

This  comparative  neglect  of  the  internal  organs  is  probably  due,  in  great  part,  to  the 
fact  that,  as  remarked  by  the  senior  author,  {2,  9),  the  average  "  human  subject  is  rarely 
available  for  the  study  of  viscera.  Usually  some  of  them  are  diseased.  The  heart  is  apt 
to  be  full  of  injection-mass.  The  brain  and  abdominal  viscera  decay  so  rapidly  that  some 
of  their  important  features  are  soon  obliterated ;  and  when,  as  is  customary,  their  removal 
is  postponed  until  after  the  examination  of  the  overlying  muscles,  their  condition  is  often 
such  as  to  render  them  unfit  for  preservation.  How  many  students  have  gained  a  good 
view  of  the  tlioracic  duct,  or  the  sympathetic  ganglia  ?  How  often  has  it  been  ascertained 
whether  a  subject  has  two  pancreatic  ducts  or  only  one?  Is  a  satisfactory  examination 
of  the  brain  made  by  the  majority  of  dissectors?"  In  short,  do  not  the  larger  number  of 
medical  students  regard  the  viscera,  even  the  heart,  as  simply  a  mass  of  ill  smelling 
material,  difficult  to  examine,  not  very  instructive,  and  worthy  only  of  the  waste  pail  ? 

Whatever  be  the  cause  of  this  inattention  to  the  viscera,  the  fact  leads  us  to  give 
ample  space  and  illustration  to  these  organs  as  they  exist  in  an  animal  peculiarly  adapted 
for  their  study  and  preservation.  Moreover,  although  a  predilection  for  surgery  prevails 
among  medical  students,  most  of  the  diseases  they  will  have  to  treat  atfect  the  viscera 
rather  than  the  skeleton  and  its  muscles ;  physiology,  too,  is  largely  splanchnological,  and 
a  correct  knowledge  of  the  brain  is  yearly  more  desirable  in  connection  with  the  pro- 
gress of  rational  Psychology. 

Lastly,  notwithstanding  the  general  preference  of  systematic  zoologists  for  skeletal 
characters — a  preference  certainly  based  upon  convenience,  and,  in  respect  to  fossil  forms, 
upon  absolute  necessity — we  are  disposed  to  think,  as  suggested  by  Gill  {1,  p.  xxvii) 
and  the  senior  author  {22,  189),  that  the  more  comprehensive  vertebrate  div^isions  should 
be  founded  upon  cerebral  and  cardiac  characters. 


CHAPTER    I. 


LIST  OP  INSTRUMENTS  AND  MATERIAL  FOR  ANATOMICAL  TECHNOLOGY — DESCRIPTION 
OF  INSTRUMENTS  AND  APPARATUS — CARE,  POLISHING  AND  SHARPENING  OF  INSTRU- 
MENTS—METHODS OF  KILLING  ANIMALS — PRECAUTIONS  FOR  CLEANLINESS— DEO- 
DORIZERS. 

§  130.  Anatomical  Instruments  and  Material. — The  follow- 
ing is  a  General  List  of  the  Supplies  required  for  anatomical  work. 
A  Special  List  will  be  given  in  connection  with  each  kind  of  manipu- 
lation. 

The  names  are  arranged  in  alphabetical  order.  Common  letters  are  used  for  the  names 
of  instruments  and  materials  which  are  desiraUe,  especially  in  a  large  laboratory.  The 
names  in  black  letter  are  of  articles  which  are  regarded  by  us  as  indispensable  to  the 
performance  of  the  best  kind  of  work. 

Several  articles  are  not  marked  indispensable  because  for  them  may  be  substituted 
others  which,  although  less  perfect  and  satisfactory,  may  be  cheaper  or  more  easily 
obtained.  For  example,  ordinary  cotton  may  be  used  instead  of  the  absorbent,  a  pail  or 
box  in  place  of  the  anaesthetic-box,  crockery  instead  of  glass,  etc.  Of  the  two  syring'es, 
the  cheaper  is  marked  indisi)ensable,  but  the  more  expensive  will  answer  the  purpose  more 
conveniently. 

In  the  first  column  are  given  the  numbers  of  the  figures  of  the  instruments  and  appa- 
ratus in  this  work.  In  the  second  column,  the  sections  are  named  when  possible.  Usually 
these  sections  occur  within  the  present  chapter,  but  in  some  cases,  as  with  Alcohol,  Jars, 
etc.,  the  articles  are  treated  of  elsewhere,  as  may  be  ascertained  from  the  Index. 

In  the  last  column  are  given  the  maximum  prices  of  the  less  familiar  articles.  They 
are  usually  taken  from  dealers'  lists,  and  are  therefore  based  upon  the  ordinary  weights  and 
measures.  It  will  be  understood  that  prices  vary  according  to  the  quality  of  the  goods, 
the  state  of  the  market,  and  the  distance  of  the  dealer  from  the  place  of  manufacture. 

Illustrated  Catalogues  of  Anatomical  and  Surgical  Instruments,  of  Tools,  of  Glass-ware, 
and  of  Chemical  Apparatus  and  Supplies,  may  be  obtained  of  dealers,  as,  for  instance, 
Codman  &  Shurtleff,  of  Boston,  Shepard  &  Dudley,  of  New  York,  and  Snowden,  of 
Philadelphia ;  A.  J.  Wilkinson,  and  Goodnow  &  Wightman,  of  Boston ;  Whitall,  Tatum 

Co.,  of  New  York  ;  J.  &  H.  Berge,  of  New  York,  and  others. 

Article.                                                                  Fig.  Sec.  Per  Price 

Absorbent  cotton 134  lb.  $1.00 

Alcohol,  ethyl ch.  Ill  gall.  2.50 

Alcoometer  (alcoholometer),  or  hydrometer "                 ..  2.00 

Angesthetic-box 29  194                ..  1.50 

Animal  charcoal 198  lb.  10 

Arseniate  of  soda . .  ch.  Ill  lb.  20 

Arthrotome 16  135               ..  70 


tf 


60 


ANATOMICAL    TECHNOLOGY, 


Article.  Fio. 

Atomizer  or  spraying  apparatus 

Bags,  coarse,  for  cats 

Basins,  graniteware 

Beaded  bristles 

Benzine 

Bistoury,  concave,  blunt  point 

'*         small,  straight,  blunt  point 14 

"  "  *'        sharp  point 

Blocks,  15  X  7  X  5  cm 

Blow  pipe,  flexible 19 

Bone  chisel 

Bottle  brushes 34 

Butcher  knife,  small 

Cans  and  boxes,  metal 

Canulae,  glass 36 

Carbolic  acid,  strong 

Cats 

Chain  hooks 

Chamois  leather 

Chloroform 

Clove  oil 

Compressor,  small 13 

Corks,  assorted 

Cork  presser 

Cosmoline  or  vaseline 

Cotton,  common 

Deodorizers 

Dishes,  glass,  covered  33 

Dissecting-gown 

Drawing  materials 

Drills  and  stock 

Emery,  finest 

Enterotome 

Ether,  sulphuric 

Filter 

Foot  lathe 

Forceps,  coarse 18 

•*        fine,  curved 20 

Glycerin,  common 

Graduate,  glass , 

Hone,  finest  Arkansas  oil-stone 

Hone,  medium 

Hydrometer  jar,  12x3  inches 

Injecting  materials,  colors,  etc 

Instrument  cases 

Jars,  glass,  wide-mouthed 

Knitting  needle,  smallest 

Lamp,  Bunsen  or  spirit 

Metric  rule,  weights  and  measures 


Pbb 


Pbice 
1.25 


137 

138 


eh.  Ill 


ch.  Ill 
142 
143 
144 

159 


145 
146 


184 

184 

ch.  Ill 

ch.  IV 

171 
ch.  Ill 


doz. 


139 

140 

•• 

•• 

lb. 

141 

pair 

lb. 


doz. 


lb. 


25 
25 
25 

25 
GO 
00 
50 


50 
.00 

8 

30 

.80 


00 
00 
CO 

75 
85 
50 


13 


INSTRUMENTS    AND    MATERIAL. 


Fio. 


11 
10 


Abtiolb. 

Muslin,  cheap  

Nail  brush 

Needles,  post  mortem 

Nippers,  large  and  medium 

Nippers,  small,  Stubs's — 

Nitric  acid 

Oil,  olive  or  sewing-machine 

Oiler,  glass  or  metal 

Parchment  for  labels 

Parchment  numbers 

Permanganate  of  potassa 

Pins,  assorted,  and  ribbon 

Plaster,  adhesive 

Plaster  of  Paris,  finest  dental 

Pliers,  round  nose,  5-inch 

Probe,  silver,  with  eyelet 

Rouge,  jeweller's 

Rubber  bands,  assorted 

Rubber  gloves 

Rubber  sheeting 

Rubber  tubing  

Saw,  back,  small 

Scales,  large  and  small , 

Scalpels,  large,  medium  and  Charriere 22-24 


21 


Scissors,  coarse,  curved  flatwise. 
Scissors,         "  "         edgewise 

"        medium,  curved  flatwise. . 

"       fine,  curved  edgewise 

"        bone 

**        hair , 

Silicate  of  soda 

Sodium  chloride  (common  salt) . . . 

Sponges,  small 

Strop,  razor , , 

Syringe,  brass,  with,  canula 

"        rubber  bulb 

"       white  metal  

Syringotome 

Tags  for  labels 

Tenaculum 

Tools,  carpenter's 

Towels,  fine  crash,  45  x  70  cm. . . 

Tracers,  sharp  and  dull 

Trays,  tin,  copper,  or  wood 

Tripod  magnifier 

Tubing,  glass,  small 

Tunnels,  fluted  tube. 

Turpentine,  spirits  of 

Twine  and  thread,  linen 


25 


25 


38 

35 
15 


17 

78 
26 


146 
146 


147 
149 
148 

198 

202 
ch.IV 


183 
106 
150 

151 
152 
153 
155 
156 


157 
158 


160 

185 
ch.  IV 
pt.  Ill 
ch.  IV 

161 

163 
164 
165 
166 

167 
pt.  Ill 


PSB 


M. 


61 

Pricb 


75 
.00 


50 


.50 

40 
,00 
.00 


25 


14 


00 
75 
75 
1.25 
2.50 
50 


35 
60 


SBC. 

Pbb 

Pri 

ch.  Til 

, , 

196 

, , 

.. 

195 

.. 

plII 

doz. 

2. 

170 

.. 

, , 

. , 

62  ANA  TOMICAL    TECHNOL  OQT. 

Abticlb.  rio. 

Vials,  large-mouthed. 

Waste  pail,  covered 

Waste  papers 

Watch  glasses pt.  II  doz.  2.60 

Wetting  bottle 27 

Wire,  brass,  copper  and  iron 

§  133.  It  will  be  seen  from  the  foregoing  list  that  the  absolutely 
necessary  instruments  for  ordinary  anatomical  work  are  compara- 
tively few  and  inexpensive. 

In  purchasing  instruments,  the  student  should  remember  that 
their  value  depends  not  upon  their  handles,  their  finish^  or  their 
cost,  hut  upon  the  adaptation  of  their  size,  form  and  temper  to 
the  worlc  in  mew. 

On  the  other  hand,  while  perfect  instruments  alone  will  not 
insure  a  good  dissection,  they  are  generally  more  easy  to  use,  and 
more  durable.  Hence  it  is  cheaper^  in  the  end,  to  purchase  the 
best. 

Left  figure,  ordinary  "cutting  nippers."  Right  figure^ 
"diagonal  side  cutting  nippers,"  called  nippers  in  this 
work.  Middle  figure,  blades  of  nippers  seen  from  the 
side. 

§  134.  Absorbent  Cotton. — This  is  cot- 
ton freed  from  all  impurities,  and  especially 
from  the  oil  which  ordinary  cotton  retains 
in  small  amount.  It  is  therefore  not 
only  cleaner,  but  capable  of  absorbing 
water  or  alcohol  instantly.  On  this  account 
Fig.  io.-Stubs's  Nippers,     -^  -^  ^^  ^^  preferred  for  the  cushions  which 

are  made  for  freshly  prepared  brains,  em- 
bryos, and  other  soft  and  delicate  specimens  to  rest  upon  while 
hardening.  It  should  also  be  used  for  packing  small  or  delicate 
alcoholic  specimens  for  transportation  ;  the  ordinary  cotton  occupies 
much  more  room  at  first  than  after  it  is  thoroughly  soaked,  and  a 
space  is  thus  left  in  which  the  specimen  can  be  shaken  to  and  fro. 
AVhen  ordinary  cotton  must  be  used  for  either  of  these  purposes,  it, 
should  be  first  thoroughly  soaJced.  For  dry  packing,  the  ordinary 
cotton  will  answer. 

§  135.  Arthrotome — Fig.  16.— This  is  a  strong  scalpel,  two 
edged  for  about  1  cm.  from  the  point.  The  handle  is  steel,  continu- 
ous with  the  blade,  and  roughened  like  that  of  the  anthropotomical, 
'^cartilage  knife."     The  arthrotome  should  be  used  for  the  rougher 


BEADED    BRISTLES. 


63 


Fig.  11.— Nippees  ;   x  1;  §  146.     German  "  Side  cutting  Nippers. 
Fig.  12.— Fine  Scissors,  curved  edgewise  ;    x  1 ;  §  156. 

work,  as  cutting  cartilages  and  separating  artlira,  so  as  to  avoid 
dulling  and  nicking  the  more  delicate  blades  of  the  scalpels.     Any 
thick  bladed  scalpel  may  be  ground  into  a  tolerable  arthrotome. 
§  136.   Beaded  Bristles. — ^These  are  easily  made.     Cut  from  a 


64  ANATOMICAL   TECHNOLOGY. 

hair  broom  a  bunch  of  the  bristles,  and  select  the  longer  and  more 
perfect  ones.  Cut  off  the  split  end  so  as  to  leave  each  bristle  5-7 
mm.  long.  Melt  red  sealing  wax  in  the  flame  of  a  lamp,  and  dip 
into  it  the  larger  ends  of  several  bristles  at  once ;  lay  them  down 
separately  and  dip  more  until  each  has  a  bit  of  the  wax.  Then  take 
them  one  by  one,  hold  them  near  the  flame,  and  turn  them  between 
the  fingers  so  that  the  wax  assumes  the  form  of  a  small  tapering 
bead.  These  bristles  are  often  useful  in  probing  for  slender  holes 
and  canals,  especially  in  the  brain  and  other  soft  parts. 

§  137.  Blocks. — These  are  of  wood,  well  oiled,  and  with  the 
edges  rounded.  They  are  used  for  supporting  the  parts  under 
dissection,  but  a  folded  wet  towel  may  sometimes  serve  the  same 
purpose. 

§  138.   Flexible   Blow  Pipe— Fig.  19.— This  is  the  whole  or 
part  of  the  ordinary  metallic  blow  pipe,  with  the  addition  of  a  " 
piece  of  rubber  tubing  30-40  cm.  long.     The  blow  pipe  may  be 
filed  in  two,  and  the  pieces  used  for  finer  and  coarser  work  respec- 
tively. 

Unlike  the  short,  straight  and  stiff  blow  pipe,  this  may  be  bent 
in  any  direction,  and  the  object  inflated  may  be  held  at  a  con- 
venient distance  from  the  eye.  Since  inflation  is  temporary  injection, 
the  advantage  of  witnessing  the  effects  during  the  operation  are 
obvious. 

A.  The  idea  of  attaching  a  flexible  tube  to  the  metal  blow  pipe  was  first  suggested  to 
us  by  Mr.  C.  F.  Clark,  a  student,  in  1874. 

B.  A  blow  pipe  of  any  size  may  be  made  by  drawing  a  bit  of  glass  tube  to  a  point,  as 
in  making  a  canula,  and  attaching  the  rubber  tube. 

§  139.  Cats. — The  price  of  cats  varies  from  five  to  twenty-five 
cents.  The  owners  of  superfluous  animals,  especially  of  such  as 
are  too  old  for  usefulness  or  comfort,  are  sometimes  glad  to  have 
them  painlessly  killed. 

The  isolated  student  can  usually  obtain  a  cat  when  it  is  needed,  but  a  laboratory  must 
keep  several  on  hand.  Contrary  to  general  expectation,  cats  rarely  quarrel  in  captivity, 
and  the  fiercest  of  them  generally  become  approachable  within  a  few  days.  But  the  fleas 
which  probably  infest  all  to  some  extent,  seem  to  multiply  more  rapidly  when  several 
cats  are  confined  together,  and  some  persons — though  comparatively  few — are  annoyed  by 
them  ;  hence  certain  precautions  should  be  observed. 

If  possible,  the  cats  should  be  kept  in  a  separate  building.  If  they  are  confined  in 
part  of  a  building  otherwise  occupied,  the'  room  should  be  isolated  by  double  doors,  etc. 
The  walls  should  be  thoroughly  plastered,  or  made  of  closely  matched  boards. 

At  least  one  window  should  be  reached  by  the  sun,  and  a  raised  platform  should  be  so 
placed  that  the  cats  can  sun  themselves  on  it.     The  windows  should  be  covered  with 


CHAIN  HOOKS.  65 

strong  wire  netting,  and  always  open  a  little  at  the  top.  In  summer  the  ventilation 
cannot  be  too  free ;  in  winter  the  room  should  be  kept  at  a  moderate  temperature  (10  to 
15°  C). 

At  least  once  a  year,  the  room  should  be  thoroughly  cleaned,  and  then  washed  with  a 
solution  of  sulphate  of  iron.  Benzine  should  be  poured  or  sprayed  into  all  the  corners 
and  cracks  to  kill  the  fleas.  If  possible,  the  room  should  be  vacant  during  the  hottest 
months. 

Shallow  boxes  of  dry  earth  should  be  placed  upon  the  floor,  and  the  earth  changed 
frequently.  Should  soiling  of  the  floor  occur,  the  feces  should  be  removed  at  once,  the 
spot  well  washed  and  saturated  with  some  deodorizer,  and  then  covered  with  a  box.  An 
uncleanly  cat  should  be  promptly  removed.  The  male  cat  is  retro niingent ;  if  one  side  of 
the  earth  boxes  reaches  to  the  height  of  about  30  cm.  (about  1  foot)  above  the  earth,  the 
walls  of  the  room  may  be  protected  from  their  strong-smelling  urine. 

Cats  like  separate  beds,  which  may  be  provided  by  placing  boxes  containing  a  little 
hay  or  "  excelsior  "  along  the  sides  of  the  room,  preferably  at  a  little  distance  from  the 
floor.     The  cats  are  better  pleased  if  half  the  top  of  the  box  is  left  upon  it. 

Fresh  catnip  should  be  strewn  about  the  room  occasionally  when  obtainable ;  the  dried 
herb  is  a  good  substitute  in  the  winter. 

Graham  crackers  and  water  should  always  be  accessible,  milk  should  be  supplied 
daily,  and  meat  once  or  twice  a  week.     The  milk  vessels  should  be  kept  clean. 

§  140.  Chain  Hooks— (See  Codman  &  Shurtleff,  A,  43,  Fig.  14). 
— These  are  used  for  fixing  or  suspending  parts  under  dissection. 
In  most  cases,  with  so  small  an  animal  as  the  cat,  these  purposes 
can  be  accomplished  by  the  use  of  the  ^^  small  compressor,"  with 
strings  or  straps  of  appropriate  length. 

§  141.   Compressor,  Small— Fig.   13.— This    name  is  given    to 
what  is  known  among  dealers  in  wearing  apparel 
as  the  *' Royal  Garment   Clasp,  No.    1."      The 
spring  which  closes  it  is  quite  strong,   and  the 
sharp  teeth  enable  it  to  retain  its  hold  under 
considerable  tension.      By  means  of  the  eyelet. 
Fig  13  —Small  Com-  *^^^  compressor  may  be  attached  by  a  string  or  a 
PKEssoR ;  X  1 ;  §  141.    strap  to  the  loop  at  the  side  of  the  tray.      For 
some  purposes  the  teeth  may  be  removed. 
§  142.    Dissecting  Gown. — In  some  cases,  the  clothes  are  suffi- 
ciently protected  by  an  apron  and  pair  of  sleeves,  or  even  by  a 
towel  upon  the  lap.      But  generally,    especially  while  injecting, 
removing  viscera,  preparing  bones,  or  performing  experiments,  one 
should  wear  a  gown  of  some  smooth  black  stuff,  like  silesia.     The 
gown  should  nearly  reach  the  ankles,  and  the  sleeves  should  be 
held  at  the  wrists  by  elastic  bands.    It  may  open  in  front,or  behind, 
bat  the  buttons  should  he  concealed  lest  they  catch  upon  the  edge 
of  a  dish  or  jar.     Soiling  of  the  wristbands  by  the  dye  of  the  gown 
may  be  prevented  by  facing  the  sleeves  with  white  linen. 
5 


Fi-ures  14-20.— Various  instruments ;  x  1.  Blunt-pointed  scalpel  §  155  ;  syringotome, 
§  16  f;  artlirotome,  §^  135  ;  tracer,  §  166  ;  coarse  forceps,  §  145  ;  flexible  blow-pipe,  ^  Idb  , 
fine  curved  forceps,  §  145. 


DRAWING    3IATEBIALS,  67 

§  143.  Dravring  Materials.— These  are  required  in  all  kinds  of 
Natural  History  work,  and  may  be  conveniently  mentioned  here. 
In  addition  to  the  writing  pencil,  there  should  be  at  least  two  for 
drawing,  the  one  of  medium,  and  the  other  of  considerable  hard- 
ness. All  pencils  should  be  *' hexagonal"  to  prevent  rolling,  or 
else  provided  with  a  hexagonal  rubber  eraser.  For  the  neatest 
work,  however,  it  is  well  to  use  a  separate  eraser  with  a  brush  for 
removing  the  crumbs  from  the  paj)er.  (See  Readers  and  Writers 
Economy  Co.,  A.)  It  is  so  often  desirable  to  double  the  size  of 
objects  that  the  "duplicating  dividers"  are  more  useful  in  place 
of  or  in  addition  to  the  ordinary  dividers.  India  ink  is  used  for 
some  drawings  and  for  writing  upon  parchment  (see  §  149). 

§  144.  Drills. — A  laboratory  should  have  2i  foot  lathe  like,  for 
example,  the  one  figured  by  Goodnow  &  Wightman,  A,  73.  But 
most  of  the  holes  required  in  bone,  wood  or  metal,  may  be  made 
by  a  small  ''Hand  drill,"  like,  for  example,  that  figured  on  p.  14 
of  the  same  Catalogue. 

§  145.  Forceps,  Coarse  and  Fine — Figs.  18,  20.— Both  pairs 
are  absolutely  necessary,  and  the  fine  ones  should  be  curved.  With 
nearly  all  forceps,  the  spring  is  too  strong  ;  it  should  be  only  sufii- 
ciont  to  separate  the  blades  when  the  pressure  of  the  fingers  is 
relaxed.  If  the  dealers  will  not  supply  forceps  with  the  proper 
spring,  the  desired  change  may  be  effected  with  a  file  or  grindstone. 
The  "Coxeter"  style  of  coarse  forceps  is  to  be  preferred.  Those 
represented  in  Fig.  18,  have  the  blades  excavated  so  as  to  be  lighter 
tlian  those  formerly  made. 

§  146.  Nippers  — Fig.  10,  11. — These  are  the  "diagonal  side 
cutting  nippers  or  pliers"  of  the  dealers  in  hardware.  The  obli- 
quity of  the  blades  to  the  handles  gives  them  great  advantages  over 
either  the  "side  cutting"  pliers,  or  the  "cross  cutting,"  which  are 
shown  in  Fig.  10,  left  figure.  Seven  sizes  are  made,  ranging  from 
10-20  cm.  (4-8  in.)  in  length.  Those  of  10  and  15  cm.  are  best 
adapted  to  anatomical  work  upon  small  animals.  The  larger  of 
these  vdll  cut  any  of  the  bones  of  cats  less  than  two  years  old,  but 
the  larger  bones  of  older  individuals  may  require  the  saw.  For 
some  purposes  the  points  should  be  quite  sharp,  and  may  be  made 
so  with  a  file  or  upon  a  grindstone. 

A.  "Pointed  nippers  with  oblique  jaws"  are  mentioned  by  Newton  (B,  22,  174),  bufe 
they  do  not  appear  to  be  in  general  use  by  anatomists.  The  nippers  have  been  used  in 
anatomical  work,  especially  for  the  removal  of  the  brain,  by  the  senior  author  since  1871, 
and  are  mentioned  in  his  paper,  1 1,  158. 


68  ANATOMICAL    TECHNOLOGY. 

B.  The  German  instruments  answer  reiy  well  for  most  pnrpcses,  and  are  much  lees 
expensive  than  the  others.  They  are  imported  by  Messrs.  H.  Boker  &  Co.,  of  New  York, 
and  may  be  had  of  A.  J.  Wilkinson  in  Boston,  and  of  Messrs.  Treman,  King  &  Co.  in 
Ithaca,  and  of  larger  dealers  generally.  The  '*  Stnbs's"  nippers  are  more  finely  tempered, 
and  better  finished.  The  smallest  size  (Fig.  10)  are  sold  by  Messrs.  Codman  &  Shurtleff" 
for  $1.     The  "bone  forceps"  of  the  surgical  price  lists  are.  still  more  expensive. 

C.  The  "cross  cutting"  nippers  are  employed  chiefly  for  cutting  wire  and  for  other 
mechanical  purposes. 

§  147.  Oiler. — A  neat  substitute  for  the  ordinary  metal  oiler 
may  be  made  by  suspending  a  dropping-tube  in  the  mouth  of 
a  vial  of  oil.  One  may  then  graduate  the  amount  more  exactly, 
and  apply  it  more  accurately ;  see  Appendix. 

§  148.  Parchment  Numbers. — Sheets  of  numbers  of  any  size 
may  be  had  at  a  reasonable  rate  from  ''Collins'  Printing  House." 
Philadelphia.  If  they  are  to  be  used  with  alcoholic  specimens,  that 
fact  should  be  mentioned  so  that  proper  drying  ink  may  be  em- 
ployed. The  numbers  may  be  pasted  upon  dry  specimens,  or 
placed  in  the  alcohol  with  wet  ones,  or  attached  to  muscles  during 
dissection  by  means  of  the  small  "ribbon  pins." 

§  149.  Parchment  for  Labels. — Numbers  and  memoranda  to  be 
attached  to  alcoholic  specimens  should  be  written  upon  parchment 
with  a  saturated  solution  of  India  ink  in  either  glacial  acetic  acid, 
or  acetic  acid  No.  8.  The  writing  should  be  alloAved  to  dry  before 
exposure  to  the  alcohol.  Parchment  is  written  upon  more  easily  if 
the  surface  is  first  rubbed  witli  a  rubber  eraser. 

§  150.  Rubber  Gloves. — These  are  an  efficient  protection  against 
contact  with  poisonous  or  malodorous  substances.  Of  course,  fine 
dissection  cannot  be  done  in  gloves,  but  it  is  sometimes  desirable 
to  protect  the  hands,  especially  in  the  manipulation  of  the  intestines, 
and  while  macerating  bones.  Like  other  rubber  articles,  the  gloves 
should  be  wiped  dry  after  using,  and  laid  in  a  cool,  dark  place. 

§  151.  Rubber  Tubing. — For  the  blow  pipe,  and  for  canulfe, 
the  lumen  should  be  3  mm.  (l-8th  inch);  the  size  next  most  use- 
ful in  the  laboratory  is  6  mm. 

§  152.  Saw — Fig.  21. — This  should  have  a  thin  blade,  and  the 
teeth  should  be  but  slightly  "set." 
It  is  used  chiefly  for  bisecting  the 
head  for  the  removal  of  the  brain, 
and  should  not  be  employed  for 
mechanical  purposes. 

o  -1  Eto     cj^^i^        Tr  i>  ^4.  Fig.  31.— Back  Saw  ;   x  .14. 

§  153.    Scales. — Very  few  cats 

weigh  as  much  as  5  kilos.,  and  heavier  ones  can  be  weighed  entire 


WEIGHING   PAN.  69 

upon  ordinary  scales.  For  most  anatomical  purposes,  therefore,  the 
scales  need  not  be  arranged  for  more  than  4-5  kilos.,  or  about  10 
lbs.  avoir.  Weights  of  less  than  1  gram  should  be  determined  by 
the  smaller  or  ^'prescription"  scales. 

Of  the  larger  scales  there  are  two  styles,  the  "  open  "  and  the  *'  box."  An  example  of 
ilie  former  is  the  "  Druggist's  trip  scales,"  figured  by  J.  &  H.  Berge,  A,  63 ;  of  the  latter, 
is  the  "  Ebony  box  scale,"  figured  by  Whitall,  Tatum  &  Co.,  A,  74.  With  a  capacity  of 
10  lbs.,  the  former  costs  $7,  and  the  latter  $14.  In  selecting  scales,  it  would  be  well  to 
obtain  the  advice  of  some  chemist  or  physicist. 

§  154.  Weighing  Pan. — Tlie  scale  pans  accompanying  the  scales 
above  mentioned  are  about  20  cm.  in  diameter,  and  will  contain  any 
separate  organ  of  the  cat,  or  the  head  or  limbs.  For  weighing  an 
adult  cat  entire,  a  larger  pan  is  needed.  For  this  purpose,  one  of 
the  ordinary  trays,  30  x  40  cm.  may  be  used,  but  it  is  better  to  pro- 
vide a  special  pan.  It  should  be  oval  or  oblong,  about  25  x  35  cm., 
made  of  stout  tin,  and  with  a  rim  about  3  cm.  high.  Its  weight 
may  be  diminished  by  punching  out  disks  not  more  than  1  cm.  in 
diameter,  until  it  exactly  balances  some  weight,  as  500  grams, 
or  a  piece  of  lead,  which,  of  course,  must  be  used  always  with  the 
pan.  If  the  cat  to  be  weighed  is  stiff,  it  may  sometimes  be  made  to 
rest  upon  the  ordinary  scale  pan  without  touching  anything  ;  other- 
wise this  special  pan  should  be  used,  the  arms  and  legs  and  tail 
being  kept  within  it. 

§  155.  Scalpels — Figs.  22,  23,  24. — These  are  single  edged,  and 
thin  bladed  knives,  with  ebony  or  ivory  handles.     The  medium  size 

Fig.  22. 


I 


Fro.  -Ti. 


COUtiAN*.-,HUHTLE.FP  COOyArJiS '^URTLEFfi- 

22. — Large  Scalpel,  for  sections  of  brain,  etc. ;  §155;  x  .5.  Fig.  23. — Medium- 
sized  Scalpel,  for  ordinary  dissecting ;  x  .5  ;  §  155.  Fig.  24. — Charriere 
Scalpel,  for  finer  dissecting ;    x  .5  ;  §  155. 


(Fig.  23)  answers  for  most  purposes,  and  will  last  a  long  time  if  care- 
fully used.  The  "Charriere"  is  employed  for  finer — but  not  the 
finest — dissecting,  and  the  large  scalpel  should  be  kept  perfectly 
smooth  and  keen  for  making  macroscopic  sections  of  the  brain, 
heartj  etc. 


70  ANATOMICAL    TECHNOLOGY. 

%  156.    Scissors — Figures  12,  25. — All  dissecting  scissors  should 
be  curved.     The  curvature  gives  three  advantages :  better  adap- 
tation to  the  surfaces  of 
animals  and  their  parts, 
which  are  rarely  plane ; 
"coDMAN  &  SHURTLEFF,  /"     ^^   the  power  to  change  the 

^°*^°'*-  ^^^   direction  of  the  cut  with- 

FiG.  25.— Coarse  Scissors  Curved  Flatwise;       out    corresponding    move- 
^•^'  §^^^-  ment  of  the  hand  or   of 

the  subject ;  the  effect  of  the  cutting  is  more  easily  observed.  For 
most  purposes,  the  blades  should  be  curved  flatwise^  as  in  Fig.  25, 
but  those  curved  edgewise,  as  in  Fig.  12,  are  sometimes  very  con- 
venient. All  coarse  scissors  should  have  locic  joints,  so  that  the 
blades  may  be  separated  for  cleaning  and  sharpening.  Fine  scissors 
should  have  sharp  and  well  matched  points.  The  medium  coarse 
scissors  are  well  adapted  to  work  upon  the  brain  and  heart,  and 
other  organs  for  which  the  coarse  scissors  are  too  large,  and  the  fine 
ones  unnecessarily  delicate. 

§  157.  The  hone  scissors  are  simply  a  strong,  blunt-pointed  pair 
of  coarse  scissors,  with  which  the  cartilages,  ribs,  and  other  hard 
or  tough  parts  may  be  cut,  so  as  to  save  the  edges  of  the  proper 
dissecting  scissors.  A  straight  pair  will  answer  the  purpose  quite 
well,  and  usually  cost  somewhat  less. 

§  158.  The  Jiair  may  be  removed  with  a  pair  of  common  cheap 
scissors ;  but  it  is  better,  especially  in  a  large  laboratory,  to  provide 
a  special  pair  of  coarse  scissors,  curved  flatwise,  and  with  the  points 
quite  blunt. 

§  159.  The  enterotome  supplied  in  j)ost-mortem  cases  is  a  pair 
of  long  scissors,  one  blade  of  which  is  enlarged  and  rounded,  and 
projects  beyond  the  other  so  as  to  precede  it  in  opening  an  intestine. 
Similar  instruments  might  be  made  for  the  cat,  but  the  same  end 
may  be  accomplished  by  guarding  one  of  the  blades  of  a  pair  of 
coarse  scissors,  especially  such  as  are  curved  edgewise.  Cleland 
suggests  (A,  155)  sticking  a  bit  of  costicartilage  upon  one  blade, 
but  a  small  rubber  stopper  will  serve  the  purpose. 

§  160.  Sponges. — Sponges  may  be  conveniently  classed  as  car- 
riage, hatJiing,  anatomical  and  surgical.  The  last  are  fine  grained, 
and  specially  prepared,  so  as  to  be  somewhat  expensive.  A  few 
such,  of  conical  shape,  are  desirable,  especially  for  experimentation. 
For  ordinary  anatomical  purposes,  sponges  should  be  small  enough 


THE    STRING OTOME,  71 

to  be  easily  grasped,  and  should  be  freed  from  sand  and  grit  before 
using.     The  larger  and  coarser  kinds  are  useful  in  various  ways. 

All  sponges  should  be  washed  after  using,  and  boiled  occasion- 
ally for  a  few  moments.  It  is  said  that  they  may  be  freshened  by 
soaking  in  brine  to  which  a  little  iodine  has  been  added. 

§  161.  Syringotome — Fig.  15. — This  is  sometimes  called  "can- 
aliculus knife."  "  It  is  a  small,  concave,  blunt  pointed  bistoury, 
which  is  very  convenient  for  delicate  work  upon  the  brain  and  heart, 
and  for  following  and  slitting  up  narrow  canals. 

The  syringotome  was  found  very  serviceable  by  the  senior  author  in  tracing  out  the 
tortuous  canals  upon  the  heads  of  sharks  and  skates  at  the  Museum  of  Comparative 
Zoology  in  186G-7.  At  his  suggestion  it  was  included  in  the  set  of  dissecting  instruments 
supplied  to  the  students  of  '  The  Anderson  School  of  Natural  History  at  Penikese  Island  " 
in  1873.  Excepting  with  the  brain,  however,  most  of  the  uses  of  the  syringotome  may  be 
subserved  by  the  less  expensive  tracer. 

§  162.  Tags. — Two  sizes  of  tags  are  needed  :  the  smaller  are  for 
numbers  or  brief  memoranda  sufficient  to  identify  the  specimen  ; 
they  are  used  by  stationers  and  dry  goods  dealers.  The  larger  are 
the  smallest  size  of  "  Dennison's  Shipping  tag,"  and  are  3.5  cm.  wide 
by  7.2  long ;  they  should  be  provided  with  strings,  and  the  eyelet 
should  be  guarded  by  a  metal  ring. 

§  163.  Tenaculmn— See  Codman  &  Shurtleff,  A,  42,  Fig.  8.— 
This  is  seldom  needed  in  felitomy. 

§  164.  Tools,  Carpenter's. — A  laboratory  should  contain  the 
ordinary  tools,  as  saw,  hammer,  screw  drivers,  awls,  bits  and  stock, 
rat  tail  and  three  cornered  files,  screw  hooks  and  eyes,  etc. 

§  165.  Towels. — Excepting  the  roller  towels,  these  should  be 
short.  The  finer  crash  is  more  expensive,  but  wears  longer  than 
the  cheaper  stuffs,  and  there  is  less  lint ;  it  may  be  had  in  rolls, 
which  may  be  cut  into  the  desired  lengths. 

§  166.  Tracer — Fig.  17. — This  is  prepared  from  a  piece  of  hex- 
agonal or  octagonal  steel  rod,  about  15  cm.  long,  and  4  mm.  in 
diameter.  The  middle  third  is  left  as  a  handle  ;  one  of  the  terminal 
thirds  tapers  to  a  blunt  point,  and  serves  as  a  probe  for  some 
purposes ;  the  other  end  tapers  in  like  manner,  and  is  bent  at  the 
tip  so  as  to  form  about  the  fourth  of  the  periphery  of  a  circle  1  cm. 
in  diameter ;  the  concavity  is  then  sharpened. 

The  value  of  the  tracer  in  isolating  vessels  and  nerves  can  hardly 
be  overestimated.  A  dull  tracer  may  be  used  also  in  lifting  Vessels 
and  nerves  that  have  been  isolated  already,  as  in  experiments. 


73 


ANAT03nCAL     TECHNOLOGY. 


A.  A  tracer  may  be  made  by  any  one  from  a  piece  of  steel  rod,  or  from  a  dental  "  exca- 
vator," but  tlie  saving  so  effected  is  hardly  worth  tlie  trouble.  The  instrument  is  made  by 
Codman  &  SImrtleff,  and  perhaps  by  others. 

B.  The  tracer  is  apparently  similar  to  the  ''seeker"  of  the  English  anatomists,  and  the 
"finder''  of  the  Germans.  The  instrument  was  introduced  into  tlie  laboratory  of  Cornell 
University  with  a  microscope  presented  by  the  late  Hon.  John  Stanton  Gould.  The  con- 
version of  the  opposite  end  into  a  tapering  probe  was  suggested  by  Mr.  Willis  N.  Rudd,  a 
student,  and  the  sharpening  of  the  concavity  was  first  proposed  by  the  junior  author. 

§  167.  Trays — Fig.  78.— These  are  usually  made  of  stout  tin,  but 
copper  is  more  durable.  If  wood  is  used,  it  should  be  tliorouglily 
oiled.  A  wire  loop  should  be  soldered  at  the  middle  of  each  end, 
and  on  each  side  at  about  one-sixth  of  the  distance  from  each  end. 

Four  sizes  of  trays  are  convenient  in  the  dissection  of  cats  : 
15x20,  20x30,  30x40,  and  40x60  cm.  The  depth  of  the  two 
smaller  sizes  should  be  about  1  cm.,  and  that  of  the  two  larger 
about  2  cm.  The  largest  size  should  be  stiffened  by  diagonals  upon 
the  bottom. 

§  168.  Tripod  Magnifier— Fig.  26.— This  is  a  simple  magnifier 
with  a  large  field,  and  mounted  upon  a  tripod  which  may  be  placed 


ISp.c. 


Fig.  26. — Tripod  Magnifier;   x  1  ;  §  168.  Fig.  27.— Wetting  Bottle;  ^  170. 

in  liquid.  While  examining  delicate  objects  out  of  liquid,  it  is 
safer  to  turn  the  legs  toward  the  eye,  or  remove  them  altogether. 
The  object  should  be  held  so  as  to  receive  the  best  light. 

§  169.  Tunnels. — Several  sizes  are  desirable,  of  both  glass  and 
tin.  The  latter  should  have  the  slender  part  fluted.  When  the 
larger  part  of  a  tin  tunnel,  or  either  part  of  a  glass  one,  is  set  into  a 
bottle  or  jar,  a  thick  string  should  be  interposed  between  it  and  the 
mouth  of  the  vessel  to  permit  the  escape  of  air  as  the  liquid  enters. 


WASTE  PAPERS.  73 

§  170.  Wetting  Bottle— Fig.  27.— The  bottle  is  about  16  x  5  cm., 
so  as  not  to  be  easily  overturned.  The  mouth  is  closed  by  a  cork 
through  which  are  passed  two  slender  glass  tubes.  One,  the  air- 
tube,  is  straight,  and  reaches  nearly  to  the  bottom  of  the  bottle  ;  the 
other,  the  spoul,  extends  but  little  below  the  cork,  and  is  curved  so 
as  to  permit  the  ready  application  of  the  contents. 

§  171.  Wetting  Mixture. — The  cheaper  commercial  glycerin  is 
to  be  mixed  with  water  in  the  proportion  of  15  per  cent,  by  measure, 
or  12  per  cent,  by  weight,  and  about  25  drops  of  clove  oil  is  to  be 
added  to  each  liter  of  the  mixture. 

§  172.  Waste  Papers. — These  are  pieces  of  paper  of  several 
sizes,  corresponding  respectively  to  the  slips,  the  sheets,  and  the 
trays. 

The  quality  of  paper  is  not  material,  so  long  as  it  is  lirm  enough 
to  hold  together  when  slightly  wet.  The  ''roll  Manilla"  paper  of 
medium  thickness  is  strong  and  cheap,  but  the  ordinary  slips  and 
sheets  which  have  been  used  by  writing  on  one  or  both  sides  may 
be  kept  for  this  purpose. 

With  fine  dissections,  or  when  only  connective  tissue  or  small 
muscles  are  to  be  removed,  the  waste  slip  may  be  placed  in  a  corner 
of  the  tray. 

With  coarser  work,  and  when  skin,  fat,  and  the  larger  muscles 
or  viscera  are  to  be  removed,  use  the  waste  sheet. 

When  the  cat  is  to  be  transected  or  eviscerated,  or  when  some 
larger  animal  is  under  dissection,  have  at  hand  extra  trays  contain- 
ing the  corresponding  waste  papers. 

The  waste  should  be  disposed  of  as  soon  as  possible,  but  in  case 
the  opportunity  for  re-exanii nation  is  desired,  the  tray  containing  it 
may  be  set  aside,  and  the  paper  will  obviate  the  objectionable 
adhesion  of  the  waste  to  the  tray  itself  which  might  otherwise 
occur. 

CAHE   OF  INSTRUMENTS. 

§  173.  In  general,  all  instruments  should  be  washed,  thoroughly 
dried,  and  slightly  oiled  as  soon  as  possible  after  using. 

The  washing  may  be  done  with  a  cloth  or  sponge,  but  the  nail 
brush  should  be  used  for  the  joints  of  nippers,  and  the  teeth  of  the 
saw.  The  wiping  may  be  done  with  a  towel,  and  then  with  a  bit 
of  cloth  or  chamois  slightly  oiled. 

All  joints  should  be  kept  well  oiled  or  vaselined. 


74  ANATOMICAL    TECHNOLOGY. 

The  oiling  should  be  especially  thorough  when  instruments  are 
to  be  packed  away  or  disused  for  some  time,  and  particularly  at 
the  sea  shore. 

Scalpels  and  other  instruments  with  wooden  or  ivory  handles 
should  not  be  allowed  to  soak  in  water,  lest  the  rivets  become  loose 
after  drying.     Wooden  handles  should  be  occasionally  oiled. 

§  174.  Blow  Pipe. — Usually  this  needs  only  to  be  wiped,  first 
with  a  moist,  and  then  with  a  dry  cloth.  After  using,  be  sure  that 
the  lumen  is  free  ;  if  clogged,  open  it  with  the  fine  knitting  needle, 
or  a  wire. 

§  175.  Forceps. — Clean  the  serrated  parts  with  the  nail  brash, 
draw  a  cloth  or  towel  between  the  blades,  and  then  wipe. 

§  176.  Nippers. — Clean  the  joint  and  blades  well  with  the  nail 
brush,  wipe  dry,  and  oil  the  joint. 

§  177.  Saw. — Use  the  nail  brush,  moving  it  from  the  back  to- 
ward the  teeth.  Wipe,  carrying  the  towel  in  the  same  direction. 
Then  wipe  dry,  and  oil. 

§  178.  Scalpels  and  Cutting  Instruments  Generally. —These 
instruments,  and  especially  such  as  have  keen  edges  and  delicate 
points,  should  be  protected  from  contact  with  each  other  and  with 
other  objects.  If  not  kept  in  a  case,  they  may  be  laid  in  a  small 
tray,  like  the  cover  of  a  note  box  lined  with  chamois  or  velveteen. 
When  several  are  to  be  carried  at  once,  each  handle  should  be  held 
between  two  fingers  so  that  the  blades  may  not  touch. 

In  wiping  a  scalpel,  hold  it  firmly  in  the  left  hand,  and  let  the 
cloth  cover  the  right  thumb  and  index,  as  in  wiping  a  table  knife  ; 
do  not  let  the  cloth  come  upon  the  edge.  The  scalpel  should  be 
wiped  four  times  :  first  with  a  moist  cloth  to  remove  all  blood  and 
fragments ;  then  with  a  dry  cloth  ;  then  with  an  oiled  cloth  or 
chamois,  and  finally  with  a  clean  dry  cloth  or  chamois.  The  fingers 
should  not  touch  the  blade  after  the  final  wiping. 

§  179.  Scissors. — If  the  blades  are  lock  jointed,  they  should  be 
separated.  The  blades  are  to  be  treated  like  the  scalpels.  Clean 
the  joint  thoroughly,  and  keep  it  oiled. 

§  180.  Trays. — If  waste  papers  are  used,  the  trays  vdll  usually 
require  only  rinsing,  after  which  they  should  be  set  up  on  edge  to 
dry.  Where  many  trays  are  used,  there  should  be  a  suitable  rack 
for  them. 

§  181.    Instrument    Cases. — The    experienced    anatomist  rarely 
uses  the  "case"   in  which,   probably,   his  first  instruments   were 


I 


PACKING    INSTRUMENTS    FOR     TRANSPORTATION.  75 

purchased.  The  ordinary  case  never  has  room  for  all  the  neces- 
sary instruments,  and  is  a  less  convenient  receptacle  for  them 
while  in  use  than  a  shallow  tray  like  the  cover  of  a  note  box ; 
see  §  110. 

If  the  student  is  unable  to  resist  the  temptation  to  possess  a 
regular  dissecting  case,  he  is  advised  to  obtain  one  of  the  more 
costly,  as  likely  to  contain  better  instruments.  The  case  commonly 
selected  by  the  special  students  at  Cornell  University  is  sold  by 
Messrs.  Schuyler  &  Co.  and  White  &  Burdick,  of  Ithaca,  for  $6.25. 
It  contains  the  following  instruments :  three  assorted  scalpels, 
coarse  and  fine  forceps,  coarse  and  fine  scissors,  arthrotome,  tracer 
and  blow  i)ipe.  Similar  cases  may  probably  be  had  elsewhere. 
The  additional  instruments  must  be  purchased  separately. 

§  182.  Packing  Instruments  for  Transportation. — AH  scalpels 
and  delicate  pointed  instruments  generally  should  be  packed  as 
follows :  thrust  the  point  into  a  bit  of  cork,  then  wrap  well  in  a 
piece  of  thin  paper,  such  as  is  supplied  in  packages  under  the  name 
of ''star  mills,"  ''diamond,"  etc.  The  paper  should  project  well 
beyond  the  blade,  and  be  twisted  or  bent  over  so  as  to  keep  the 
cork  in  place.  Thus  wrapped,  the  most  delicate  instruments  may 
be  sent  by  mail  in  pasteboard  or  light  wooden  boxes,  or  otherwise 
transported.  Since  no  written  communication  is  permitted  upon 
such  a  package  without  payment  of  letter  rates,  the  consignee 
should  be  notified  at  the  same  time.  Whether  for  mailing  or  any 
other  kind  of  transportation,  the  heavier  instruments,  or  such  as 
need  no  special  protection,  should  be  packed  separately  from  the 
more  delicate.  Small  cigar  boxes  answer  a  good  purpose,  but  the 
most  suitable  boxes  for  instruments  are  made  by  the  Swift  Manu- 
facturing Co.  of  New  York,  and  others  ;  they  are  long  and  narrow, 
and  provided  with  lids. 

POLISHING  INSTRUMENTS. 

§  183.  A.  Instruments  that  have  become  tarnished  may  be  re- 
polished  by  rubbing  with  a  piece  of  chamois  or  cloth  on  which  has 
been  put  oil  and  rouge.  Perhaps  the  best  way  to  apply  the  polish- 
ing material  is  to  wrap  the  cloth  around  the  end  of  the  index  for 
small  instruments,  or  roll  the  cloth  or  chamois  into  a  bundle  for 
large  instruments.  In  both  cases  the  surface  to  be  polished  is 
rubbed  as  in  scouring  household  knives,  taking  care  to  avoid  con- 
tact with  the  edge  of  the  instrument. 


76 


ANA  TOMICAL     TECHNOL  OGY. 


B.  Rust  should  Ibe  removed  with  a  dull  knife  and  then  the 
polishing  may  be  done  as  above.  When  an  instrument  is  badly 
tarnished,  the  polishing  with  rouge  is  a  tedious  process.  In  that 
case,  tine  emery  may  be  used  to  remove  the  tarnish,  and  then  rouge 
for  the  final  polish.  The  emery  should  be  applied  as  directed  for 
rouge. 

C.  If  one  has  access  to  a  polishing  wheel  the  process  is  shortened  greatly.  The 
same  materials  are  used  as  in  polishing  by  hand  and  in  the  same  order. 

D.  Emery  of  exceeding  fineness  may  be  easily  prepared  as  follows :  Fill  a  high  narrow 
vessel  like  a  preserving  jar,  nearly  full  of  water,  and  put  into  it  about  200  grammes  of 
ordinary  flour  of  emery.  Agitate  thoroughly,  and  after  the  vessel  has  stood  half  a  minute 
pour  off  the  liquid  into  another  dish.  Add  more  water  to  the  first  vessel  and  agitate  again, 
and  pour  off  the  liquid  as  before.  The  larger  particles  sink  first,  and  hence  the  emery  in 
the  water  poured  off  is  much  finer  than  that  left.  Allow  the  emery  to  settle  from  the  first 
and  second  washinpjs  and  pour  off  the  water  and  dry  the  emery.  Several  grades  may  be 
obtained  in  this  simple  way. 

E.  Instruments  may  be  very  nicely  polished  by  using,  in  place  of  rouge,  the  fine 
whitish  ashes  that  may  be  found  in  the  upper  parts  of  stoves  in  which  anthracite  coal  is 
burned. 

F.  If  rouge  is  added  to  the  oiled  leather  used  for  wiping  the  instruments  after  they 
are  washed  (§  178),  the  polish  may  be  retained  indefinitely. 

SHARPENING    INSTRUMENTS. 

§  184.  Honing. — For  honing,  it  is  desirable  to  have  two  oil 
stones,  one  very  fine  for  finishing,  and  one  somewhat  coarser  for 


Turning  knife. 


Honing. 


Stropping. 


Fig  28. — Honing  and  Stropping  Knives.  The  upper  figure  shows  how  the  knife  is 
to  be  turned  upon  its  back  in  reversing  the  movement.  The  left  figure  shows  the 
edge  ward  movement  of  the  blade  in  honing;  the  right,  the  backward  movement  in 
stropping.    §§  184,  185. 


HONING.  77 

commencing  the  sharpening,  and  for  sharpening  the  coarser  instru- 
ments. 

A.  Place  several  drops  of  fine  olive  or  sewing-machine  oil  on  the 
stone  and,  with  a  cloth  devoted  to  the  purpose,  rub  the  surface  to 
remove  all  dirt  and  expose  the  cutting  particles  of  the  stone.  After 
the  stone  is  well  wiped,  put  two  or  three  more  drops  of  oil  upon  it, 
and  spread  it  around  with  a  scalpel  blade. 

B.  Look  at  the  edge  of  the  instrument  to  be  sharpened  with  the 
tripod  magnifier,  holding  the  edge  of  the  blade  up  and  between  the 
eye  and  the  light.  This  is  to  see  if  there  are  any  nicks  in  the  edge. 
If  there  are  nicks,  they  should  be  removed  by  rubbing  the  edge  on 
the  fine  stone.  After  making  two  or  three  sweeps  across  the  stone, 
look  at  the  edge  again  to  see  if  all  the  nicks  are  removed.  If  they 
are  not,  continue  to  grind  the  edge  on  the  stone  till  they  are.  If  the 
nicks  are  slight  the  edge  need  be  ground  off  only  in  their  immediate 
vicinity.  If  they  are  deep,  however,  the  entire  edge  should  be  re- 
moved or  it  will  become  wavy. 

When  the  edge  is  smooth  and  free  from  nicks  it  should  be 
honed ;  if  quite  dull,  first  on  the  coarse  and  then  on  the  fine 
stone. 

C.  In  case  the  instrument  is  a  scalpel,  (1)  grasp  the  handle  in 
such  a  way  that  the  index  and  medius  shall  oppose  the  pollex,  and 
the  end  of  the  handle  shall  touch  the  palm.  (2)  Place  the  blade 
flat  on  the  stone  as  shown  in  Fig.  28,  and  then  lift  the  back  very 
slightly.  (3)  Move  the  knife  with  a  curving  sweep  toward  the  left, 
as  shown  by  the  arrow,  so  that  the  point  of  the  blade  shall  be  at 
the  lower  left  corner  at  the  end  of  the  sweep.  (4)  Then  turn  the 
blade  over,  always  turning  the  edge  away  from  the  stone.  Do  this 
by  rolling  the  handle  in  the  fingers.  (5)  After  the  knife  is  turned,  it 
should  be  moved  across  the  stone  from  left  to  right  exactly  as 
described  for  the  motion  from  right  to  left.  The  handle,  of  course, 
points  in  the  opposite  direction. 

In  this  method  of  honing,  which  is  that  employed  by  the  best  cutlers,  the  edge  precedes 
the  hack;  the  blade  is  so  placed  on  the  stone  that  it  follows  the  handle,  and  the 
sharpening  is  from  heel  to  point.  If  the  blade  were  pushed  across  the  stone  instead  of 
being  drawn  as  above,  the  sharpening  would  be  from  point  to  heel. 

D.  In  the  beginning  of  the  honing,  one  may  press  quite  firmly 
and  draw  the  same  side  of  the  blade  over  the  stone  three  or  four 
times  without  turning  it ;  but  when  the  edge  becomes  thin,  the 
blade  should  be  turned  at  every  sweep. 


78  ANATOMICAL    TECHNOLOGY. 

E.  In  case  the  edge  should  turn  over,  producing  the  so-called 
wire  edge^  it  must  be  removed  by  drawing  the  edge  along  some  fine- 
grained substance  like  horn  or  ebony.  One  should  be  careful  not 
to  get  any  of  the  detached  wire  edge  on  the  stone,  as  it  would  be 
liable  to  produce  nicks  in  the  edge  of  the  knife. 

F.  (1)  Use  the  coarse  stone  until  the  knife  will  cut  a  thin  shaving 
from  the  convex  surface  of  smooth  writing  paper.  (2)  Wrap  the 
paper  around  a  lead  pencil,  remove  the  pencil  and  rest  the  blade 
flat  upon  the  paper.  Press  down  slightly,  and  push  the  blade, 
edge  forward^  along  the  top  of  the  curve.  If  the  knife  is  sharp,  it 
will  cut  a  thin  shaving  from  the  paper.  (3)  Another  very  excellent 
way  to  judge  of  moderate  sharpness  is  to  rest  the  tang  of  the  blade 
on  the  end  of  the  medius,  and  to  feel  of  the  edge  by  moving  the  ball 
of  the  index  along  it  in  such  a  way  that  if  a  cut  were  made  it 
would  be  a  mere  shaving  from  the  cuticle  like  that  from  the  paper. 
If  the  knife  is  sharp,  it  will  take  hold,  as  it  is  called,  that  is,  one 
can  feel  that  it  is  cutting.  The  ball  of  the  index  is  very  sensitive, 
and  one  can  judge  quite  correctly  of  the  smoothness  and  sharpness 
of  the  edge.  Those  who  object  to  trying  the  edge  on  the  skin 
can  employ  a  bit  of  smooth  grained  cork. 

G.  (1)  When  the  edge  is  sufiiciently  sharp  throughout  its  entire 
extent  to  cut  a  shaving  from  the  cylindrical  paper,  or  to  take  hold 
of  the  finger  or  the  edge  of  the  cork,  the  fine  stone  may  be  used. 

(2)  In  using  the  fine  stone  the  blade  should  be  turned  at  every 
sweep.  Use  the  fine  stone  until  the  knife  will  cut  a  hair  near  its 
base  or  near  the  point  where  it  is  held. 

(3)  It  often  happens  that  some  parts  of  an  edge  are  sharp  and 
others  not.  In  such  a  case  the  dull  parts  alone  can  be  applied  to 
the  stone  by  using  the  edge  of  the  stone. 

When  the  scalpel  will  cut  a  hair  close  to  a  fixed  point,  it  is 
sufficiently  sharp  for  ordinary  dissecting. 

I  185.  Stropping. — A  good  razor  strop  is  required,  as,  e.  g., 
"Emersons'." 

The  strop  is  to  give  the  final  keenness  and  smoothness  to  the 
edge  of  a  cutting  instrument.  It  is  a  waste  of  time  to  employ  it 
before  the  degree  of  sharpness  indicated  for  the  fine  stone  is 
attained,  as  the  strop  sharpens  very  slowly. 

A.  (1)  Grasp  the  knife  exactly  as  for  honing.  (2)  The  blade  is 
carried  across  the  strop  with  a  long  curving  sweep  just  as  de- 
scribed for  honing  except  that  the  bacTc  of  the  Made  precedes  the 


KILLING    ANUIALS    FOR  DISSECTION.  79 

edge.  (Fig.  28.)  (3)  The  blade  should  be  turned  at  the  end  of 
every  sweep  across  the  strop,  thus  drawing  it  from  right  to  left  as 
often  as  it  is  drawn  from  left  to  right. 

B.  (1)  Use  first  the  red  and  then  the  black  side  of  the  strop. 
(2)  Press  only  moderately.  The  nearer  a  perfect  edge  is  attained 
the  more  lightly  should  one  press. 

(3)  Continue  the  stropping  on  the  red  side  until  the  knife  will 
cut  a  hair  of  the  head  1  cm.  from  the  point  where  it  is  grasped  by 
the  fingers  ;  then  employ  the  black  side. 

(4)  Continue  to  use  this  side  until  the  knife  will  cut  a  hair  from 
the  liead  2-3  cm.  from  the  point  where  it  is  held,  or,  what  is  a  better 
test,  until  it  will  cut  the  fine  hairs  on  the  dorsum  of  the  hand  and 
wrist  half  a  centimeter  from  their  base  when  the  knife  is  moved 
distad — toward  the  ends  of  the  fingers.  If  the  knife  has  a  perfect 
edge  it  will  cut  these  fine  hairs  so  easily  that  one  can  hardly  tell  by 
the  feeling  when  a  hair  is  divided. 

§  186.  Scissors. — These  are  much  more  difficult  to  sharpen  than 
scalpels,  and  tlie  fine  ones  should  be  sent  to  the  makers  unless 
one  is  very  skillful.  Place  the  blade  so  that  the  oblique  face 
formed  by  grinding  shall  rest  flat  on  the  stone.  Draw  the  blade, 
edge  foremost,  across  the  stone  with  a  curving  sweep  as  for  scalpels 
(§  184,  C  [3]  ).  Test  for  sharpness  with  the  finger  or  by  attempting 
to  cut  moistened  tissue  paper  (§  184,  F  [3]  ). 

§  187.  Tracer,  Syringotome  and  Concave  Edges  Generally. — 
In  sharpening  instruments  of  this  kind  one  should  use  the  edge  of 
the  stone  instead  of  its  face.  The  edge  of  the  stone  should  be  some- 
what rounded.  In  sharpening,  draw  the  blade  along  the  stone  so 
that  the  edge  precedes  the  back  as  for  scalpels  (§  184,  C  [3]  ).  Test 
the  sharpness  with  the  finger  (§  184,  F  [3]  ). 

§  188.    The  care  and  sharpening  of  instruments  are  considered  by  Mojsisovics,  A,  13  ; 
Holtzapflel,  A,  III,  1026-1156;  Hyrtl,  A,  23-37;  Straus-Durckheim,  B,  1,  158-160. 

KILLING  ANIMALS   FOR  DISSECTION. 

§  189.  There  is  usually  no  difficulty  in  taking  a  cat  when  it  is 
wanted.  Such  as  will  not  come  when  called  may  be  secured  by 
means  of  a  strong  net,  or  by  using  a  bag  attached  like  a  net  to  a 
hoop  and  pole. 

The  bag  referred  to  is  of  strong  coarse  material,  and  commonly 
used  for  oats.     In  such  a  bag  the  cat  may  be  left  for  several  hours ; 


80  ANATOMICAL    TECHNOLOGY. 

but  the  closer- woven  bags  which  are  used  for  flour  do  not  admit 
sufficient  air. 

§  160.  Methods  of  Killing— (Bernard,  A,  149-182).— Two  things 
are  to  be  considered  in  killing  animals  for  dissection  : — 

(1.)  The  death  should  be  as  nearly  painless  as  possible. 

(2.)  None  of  the  organs  or  tissues  to  be  examined  should  be 
injured  by  the  method  employed. 

§  191.  Drowning  fulfils  the  above  requirements  fairly  well. 
Judging  from  the  experience  of  human  beings,  death  by  drowning 
is  attended  with  very  brief  physical  discomfort. 

Place  the  cat  in  a  wire  cage,  or  loose  meshed  bag,  and  immerse 
it  completely  in  water  for  four  or  five  minutes.  Usually  a  cat  can- 
not be  resuscitated  after  it  has  been  completely  immersed  for  ninety 
seconds ;  after  four  or  fiYQ  minutes,  spontaneous  resuscitation  is 
altogether  improbable. 

§  192.  Chloroforming  is  preferable  to  drowning,  since  no  liquid 
is  drawn  into  the  lungs,  and  the  hair  is  not  filled  with  water.  The 
death,  too,  with  cats,  seems  to  be  quietly  going  to  sleep.  There  is 
usually  no  struggling,  showing  that  the  period  of  intoxication  by 
the  chloroform  is  very  short. 

Place  the  cat  in  the  ansesthetic  box  (see  Fig.  29).  This  is  easily 
accomplished  if  the  cat  is  in  a  bag  by  placing  the  mouth  of  the  bag  in 
the  box,  whereupon  the  cat  will  usually  walk  in  of  its  own  accord. 
After  the  cat  is  in  the  box  and  the  door  closed  and  fastened,  remove 
the  cork  from  the  hole  in  the  edge  and  pour  5-10  cc.  of  chloroform 
upon  the  furled  curtain.  Then  unfurl  the  curtain  by  means  of  tlie 
string ;  this  will  expose  a  greater  surface  from  which  the  chloroform 
can  evaporate.  Usually  the  cat  will  be  asleep  in  three  minutes,  and 
dead  in  twenty  minutes.  Bo  not  remove  it  from  the  box  till  all 
signs  of  respiration  have  ceased. 

If  etlier  is  used,  15-20  cc.  is  required  for  a  cat. 

A.  If  one  does  not  possess  the  anaesthetic  box,  cats  may  be  chloroformed  as  follows : 
Place  a  newspaper  on  the  floor,  and  invert  over  it  a  large  wash-bowl  or  a  small  tight  box 
or  pail.  Put  the  cat  under  the  receptacle,  and  pour  10  cc.  of  chloroform  on  a  sponge  or 
a  bit  of  cotton,  and  put  it  under  the  receptacle  with  the  cat.  The  box,  or  whatever  is 
used,  must  be  held  down,  or  a  weight  must  be  placed  upon  it,  while  the  animal  is  coming 
under  the  influence  of  the  anaesthetic. 

B.  Dogs  moan  while  becoming  anassthetized,  but  presumably  they  and  all  other  ani- 
mals may  be  killed  painlessly  with  chloroform  or  ether.  Tlie  amount  required  to  kill  an 
animal  varies  with  its  size,  and  with  the  size  and  closeness  of  the  box. 

§  193.   Killing  Fleas. — If  the  cat  has  fleas,  as  is  usually  the  case, 


I 


PRECAUTIONS    FOB     CLEANLINESS,     ETC. 


81 


open  the  box  after  fifteen  minutes,  and  throw  over  it  20  cc.  of  ben- 
zine. Reclose  the  door  of  the  box  and  leave  it  for  ten  or  fifteen 
minutes  longer.  Fleas  revive  from  the  chloroform  used  in  killing 
the  cat,  but  they  do  not  revive  if  benzine  is  used. 

Do  not  use  the  benzine  until  the  cat  is  completely  anaesthetized, 
for  it  causes  great  discomfort. 

§  194.  The  Anaesthetic  Box — Fig.  29.— This  is  a  close  box,  the 
'  base,  frame  and  door  being  of  wood,  and  the  rest  of  "  double-thick'* 


Pig.  29.— The  Anaesthetic- box  ;   x  .1. 

glass.  The  dimensions  are  given  in  the  figure.  The  base  and  frame 
should  be  grooved  for  the  reception  of  the  glass,  and  the  whole 
should  be  put  together  with  screws  to  permit  the  renewal  of  the 
glass  in  case  of  breakage. 

Along  one  side,  near  the  top,  runs  a  thick  brass  wire,  on  which 
slides  a  curtain,  moved  by  a  string.  Just  above  the  curtain,  when 
furled,  is  a  hole,  which  is  closed  by  a  cork  secured  from  loss  by  a 
string.  The  leather  handle  is  convenient  in  lifting  and  moving  the 
box. 

The  cost  of  the  cat-box,  including  the  glass,  is  about  $1.50. 

Almost  any  close  vessel  or  box  will  answer  for  the  administra- 
I  tion  of  a  fatal  dose  of  chloroform,  but  for  experimental  purposes 
I  the  progress  of  anaesthesia  must  be  observed. 


PRECAUTIONS  FOR  CLEANLINESS,    COMFORT  AND 

HEALTH. 

!        §  195.    Waste  Papers. — These  have  been  referred  to  in  §  172, 
and  are  mentioned  here  again  because  of  the  tendency  of  beginners 
itc)  neglect  a  very  essential  element  of  neatness  in  anatomical  work. 
-    §  196.    Waste  PaiL— This  should  ba  of  galvanized  iron,  copper 


82  ANATOMICAL     TECHNOLOGY. 

or  zinc,  never  of  wood  or  tin  ware.  The  cover  should  be  of  the 
same  material,  and  fit  closely.  The  pail  should  be  emptied  at 
night,  rinsed,  and  a  few  cc.  of  permanganate  of  potash  solution 
poured  into  it.  Once  a  week  it  should  be  thoroughly  scoured  and 
dried. 

§  196.  Waste  Pit.— The  single  student  may  readily  dispose  of 
the  refuse  of  his  work,  but  some  special  provision  must  be  made 
for  a  laboratory. 

In  cities,  communication  may  sometimes  be  had  with  the  sewer. 
The  opening  into  the  sewer  should  have  at  least  two  lids,  closely 
fitting,  and  should  be  within  a  closet  or  cupboard  provided  with  a 
special  flue  so  that  the  sewer  gas  may  not  be  drawn  into  the  labo- 
ratory. 

In  smaller  towns,  and  at  many  universities,  the  readiest  mode 
of  disposal  of  refuse  is  to  have  a  pit  dug  in  dry  soil  at  a  convenient 
distance.  The  mouth  of  the  pit  should  be  kept  from  falling  in  by  a 
cask  or  box,  and  should  be  closely  covered.  The  earth  removed 
in  digging  the  pit  should  be  kept  at  hand  under  cover,  and  some  of 
it  sprinkled  over  the  offal  at  night.  When  filled  within  half  a  meter 
of  the  surface,  the  pit  should  be  filled  up  compactly  with  earth. 

§  197.  Sink. — This  should  be  of  iron,  galvanized  iron,  zinc  or 
copper,  or  lined  with  one  of  these  materials.  It  should  be  slightly 
inclined,  the  outlet  should  be  at  the  lower  end,  and  guarded  with  a 
movable  grating.  The  escape-pipe  should  be  of  ample  size,  and 
trapped  at  some  point  which  can  be  reached. 

Excepting  just  over  the  escape,  the  sink  should  be  covered 
by  one  or  more  wooden  lids  on  hinges  which  may  be  raised  from 
the  front  and  rested  against  the  wall  behind  the  sink.  These 
lids  should  be  of  hard  wood,  and  well  oiled  or  painted.  In 
each  lid  should  be  cut  an  oval  or  elliptical  hole  for  a  basin. 
The  longer  diameter  of  the  hole  should  correspond  with  that  of 
the  sink,  so  that  the  basin  may  be  emptied  without  lifting  it  from 
its  place. 

If  there  is  no  general  water  supply,  a  water  cask  or  lead  lined 
box  may  be  placed  above  the  sink.  In  any  case,  the  faucets  should 
be  nearly  on  a  level  ^vith  the  face  of  one  standing  at  the  sink,  and 
the  water  should  be  conducted  therefrom  through  flexible  rubber 
tubes  ending  a  little  above  the  basin.  The  tube  must  be  firmly 
secured  to  the  faucet,  and  must  not  be  sharply  bent  if  the  pressure 
of  water  is  considerable. 


DEODORIZERS.  83 

Hair^  plaster  of  Paris^  sand^  and  fine  particles  generally  must 
not  be  fhroion  in  the  sink. 

The  sink  should  be  thoroughly  emptied  and  washed  at  night. 
A  convenient  instrument  for  scraping  out  the  sink,  or  cleaning  a 
table  or  tray,  is  a  piece  of  heavy  rubber  moulding,  provided  with  a 
handle. 

§  198.  Deodorizers. — Most  of  the  unpleasant  smells  which 
would  otherwise  attend  work  in  practical  anatomy  may  be  avoided 
by  preserving  the  material  in  alcohol,  by  removing  the  intestines 
within  twenty-four  hours  after  death,  and  by  the  observance  of 
other  due  precautions  for  cleanliness.  But  maceration  is  necessarily 
offensive,  and  sometimes  valuable  specimens  are  more  or  less  de- 
composed before  their  reception  ;  it  is  therefore  necessary  in  some 
cases  to  employ  deodorizers. 

Animal  Charcoal. — This  effective  deodorizer  may  be  sprinkled 
over  the  surface  of  offensive  specimens,  and  is  especially  service- 
able when  such  have  to  be  transported.  Its  use  in  the  improve- 
ment of  old  alcohol  is  described  in  Ch.  III. 

Alcohol. — If  the  specimen  is  of  moderate  size,  and  is  to  be  pre- 
served as  a  whole  or  in  great  part,  the  putrefaction  may  be  checked 
by  immersion  in  strong  alcohol,  from  75  to  95  per  cent.  The  alcohol 
may  be  poured  over  the  specimen,  or  the  latter  may  be  immersed 
I  in  it,  or  covered  by  cloths  saturated  with  it.  In  either  case,  the 
'  alcohol  will  become  offensive,  and  must  be  deodorized  by  filtration 
before  mixing  with  other  alcohol  or  use  upon  other  specimens.  The 
stronger  the  alcohol,  the  more  decided  is  its  action,  but  its  clearness 
is  unessential. 

Potassium  Permanganas. — This  is  an  excellent  deodorizer.  A 
saturated  solution  should  be  kept  at  hand,  and  a  few  cc.  poured 
into  the  waste  pail  at  night,  and  into  any  other  malodorous  jar  or 
vessel.     It  stains  the  skin  temporarily. 

Sulphate  of  Iron — Copperas. — This  cheap  deodorizer  may  be 
used  in  place  of  the  more  efficacious  but  more  expensive  perman- 
ganate of  potash.  The  coarsely  powdered  crystals,  or  a  saturated 
solution,  may  be  placed  in  the  sink,  pail,  or  pit. 

A  solution  of  Chloride  of  Lead  is  recommended  in  TJie  Medical  Record,  August  20, 1881, 
p.  232. 

§  199.  Discharges  from  the  Cat.— The  following  precautions 
are  always  desirable,  and  should  never  be  neglected  in  demonstra- 
tions or  experiments  upon  cats  before  a  class  :— 


84  ANATOMICAL    TECHNOLOGY. 

"W  hen  the  cat  is  dead,  or,  in  experiment,  qnite  asleep,  place  it 
upon  a  traj.  Roll  some  common  cotton  between  the  fingers  into  a 
somewhat  tirm  conical  plug  or  suppository  about  5x1  cm. 

Dorsiduct  the  tail  of  the  cat  so  as  to  expose  the  anus  and  open 
it  slightly.  With  the  large  forceps  grasp  the  plug  obliquely  near 
the  tip  and  force  it  into  the  rectum.  Then  pnsh  it  completely 
beyond  the  constricted  orifice  with  the  forceps  or  a  smootli,  lounded 
stick.  If  the  cat  has  been  affected  by  diarrhea,  it  may  be  necessary 
to  insert  a  second  plug. 

Let  the  buttocks  of  the  cat  project  slightly  beyond  the  edge  of 
the  tray,  over  the  sink  or  some  other  receptacle  ;  then  press  firmly 
and  steadily  upon  the  abdomen  just  cephalad  of  the  pubes.  If  the 
cat  is  a  female,  the  urine  will  usually  flow  out  readily ;  if  it  does 
not  appear,  as  is  often  the  case  with  males,  it  is  not  likely  to  be 
forced  out  during  the  subsequent  operations. 

The  urine  of  cats  has  a  very  offensive  odor,  and  should  not  be 
allowed  to  flow  into  the  tray,  or  to  reach  the  hair  of  the  animal. 

Remove  any  escaped  urine  or  feces  with  a  bit  of  cotton,  followed 
by  washing  if  necessary. 

If  the  left  hypochondrium  is  prominent,  or  if  there  is  other 
evidence  that  the  stomach  is  distended  with  food,  let  the  mouth  pro- 
ject beyond  the  tray  over  a  receptacle,  and  compress  the  whole 
abdomen.  If  any  matters  escape  from  the  stomach,  the  mouth 
should  be  washed  afterward  with  a  stream  of  water. 

§  200.  Malodorous  Parts.— On  account  of  their  contents,  the 
stomach  and  intestine  become  offensive  very  soon  after  death,  espe- 
cially if  exposed  to  the  air. 

In  some  cases  it  may  not  be  necessary  to  open  the  abdomen 
during  the  dissection  of  a  fresh  specimen  ;  decomposition  will  then 
proceed  less  rapidly,  and  the  effects  will  be  less  obvious. 

If  the  abdomen  is  opened,  these  hollow  viscera  should  be  either 
removed  soon,  or  so  treated  as  to  lessen  or  prevent  the  production 
of  offensive  odors.  The  large  intestine  especially  may  usually  be 
examined  during  the  first  or  second  day,  so  as  to  be  removed. 

When  any  part  of  the  alimentary  canal  is  divided,  the  site  of 
the  intended  incision  should  be  freed  from  its  contents  for  at  least 
2  cm.  ;  then  two  ligatures  should  be  applied  at  least  1  cm.  apart, 
and  the  cut  made  betw^een  them  ;  see  Fig.  41. 

When  it  is  undesirable  to  remove  the  intestine,  most  of  the 
offensiveness  may  be  avoided  by  expelling  the  contents.     The  con- 


DISSECTION  WOUNDS.  ^5 

tents  of  the  large  intestine  are  readily  forced  out  by  manipulation, 
the  cotton  plug  of  course  having  been  removed.  Those  of  the  small 
intestine  may  be  made  to  flow  out  with  a  stream  of  water  injected 
into  it  near  the  stomach  by  means  of  a  syringe,  or  from  a  faucet. 

The  water  should  be  pressed  out  of  the  intestine,  and  alcohol 
then  thrown  into  it.  The  alcohol  may  be  retained  if  the  plug  ia 
returned  to  the  anus ;  or  a  ligature  may  be  placed  about  the  rectum. 

§  201.  Dissection  Wounds. — Slight  dissection  wounds  have  oc- 
casionally been  received  in  the  anatomical  laboratory  of  Cornell 
University,  but  the  results  have  been  nowise  different  from  similar 
cuts  inflicted  under  ordinary  circumstances. 

So  far  as  our  experience  goes,  it  is  prohahle  that  no  danger  need 
he  apprehended  from  a  wound  received  during  the  dissection  of 
any  well  preserved  alcoholic  specimen^  or  of  any  healthy  cat^ 
whether  fresh  or  otherwise. 

In  proportion  to  the  number  of  human  bodies  annually  dissected  or  examined  in 
necropsies,  serious  dissection  wounds  are  very  few.  Indeed,  the  actual  number  of  such 
cases  is  so  small  that  statistics  are  wanting  to  enable  us  to  determine  with  accuracy  the 
conditions  under  which  the  consequences  are  likely  to  be  injurious.  A  few  writers 
believe  these  results  to  be  due  to  "  the  absorption  and  irritation  of  a  putrescent  fluid  ;  but 
this  explanation  will  hardly  account  for  the  frequency  of  the  disease  after  contact  with 
recent  bodies  before  putrefaction  has  set  in,  and  especially  of  persons  who  have  died  of 
acute  disease,  such  as  puerperal  fever,  peritonitis,  etc.,  and  for  the  affection  of  several  per- 
sons at  the  same  time,  from  the  same  body  and  with  the  same  symptoms." 

In  view  of  the  insufficiency  of  our  knowledge,  and  of  the  fact  that  dissection  wouiids 
are  most  apt  to  occur  with  beginners,  one  of  the  advantages  of  the  cat  as  a  subject  of  pre- 
liminary anatomical  work  is,  that  the  subject  may  be  obtained  healthy  and  fresh,  and  be 
preserved  in  alcohol  at  slight  expense, 

§  202.  Precautions. — Dissection  wounds  should  be  avoided  by 
care  in  the  use  of  cutting  and  pointed  instruments,  and  by  guard- 
ing against  contact  with  the  sharp  points  and  edges  of  bones  which 
have  been  broken  or  cut. 

Before  commencing  work  upon  a  suspected  animal,  or  upon 
decomposing  flesh,  or  upon  macerated  bones,  the  hands  may  be 
anointed  with  some  kind  of  fat,  as  cosmoline,  vaseline,  olive  oil  or 
"cold  cream." 

If  the  skin  is  already  broken,  rubber  gloves  may  be  worn,  as  in 
macerating  or  in  handling  offensive  viscera,  etc.,  where  no  delicacy 
of  manipulation  is  required.  In  ordinary  dissection  upon  a  suspected 
subject,  the  cuts  or  abrasions  may  be  cauterized  with  strong  carbolic 
or  nitric  acid,  or  covered  by  several  thicknesses  of  adhesive  plaster. 


86  ANATOMICAL    TECHNOLOGY, 

If  the  hands  can  be  kept  dry,  the  common  court  plaster  or  isin- 
glass plaster  will  suffice ;  but  if  they  are  to  be  wet,  it  is  safer  to  use 
the  diachylon  or  lead-plaster,  which  does  not  easily  wash  off,  but 
must  be  warmed  before  application  or  removal. 

In  cauterizing,  use  a  slender,  pointed  stick ;  dip  it  first  into  the 
acid,  and  then  into  the  open  place  of  the  skin. 

§  203.  Treatment— "Local  applications,  if  used  at  all,  must  be 
employed  immediately,  decisively,  and  effectually.  Should  a  per- 
son be  in  bad  health  at  the  time  of  receiving  a  prick  or  wound 
during  dissection,  no  matter  what  condition  the  subject  may  be  in, 
it  behoves  him  to  pay  immediate  attention  to  the  injury,  and  anti- 
cipate any  further  consequences." 

"  Should  the  wound  be  received  while  engaged  on  a  recent  sub- 
ject, and  one  which  had  died  from  acute  disease,  much  more 
caution  and  attention  are  required,  even  if  he  be  in  the  best  of 
health.  The  part  should  be  weU  cleansed,  and  a  temporary  liga- 
ture applied  immediately  above  (centrad  of)  the  wound ;  then  the 
bleeding,  if  any,  should  be  encouraged  to  flow  freely ;  where  there 
is  no  bleeding,  suction  must  be  employed ;  [this  may  be  by  the 
mouth  if  the  skin  and  mucous  membrane  are  intact,  otherwise  by 
means  of  a  tube,  or,  better,  a  cupping  glass  the  exhaustion  of  which 
is  produced  by  means  of  a  rubber  bulb]."  Then  cauterize  as 
directed  above. 

The  foregoing  directions  for  immediate  treatment  are  taken  from 
Holmes  (T.)  A,  621,  and  Clarke,  A,  54. 

Whenever  ill  effects  are  anticipated,  proper  medical  advice 
should  be  sought  without  delay. 


CHAPTER    II 


GENERAL     DESCRIPTION     OF     THE      SKELETON— ANATOMICAL      LANDMARKS — ABDOMINAL 

TRANSECTION. 

GENERAL  DESCRIPTION  OF  THE  SKELETON. 

§  204.  The  softer  parts  of  the  body  are  protected,  supported,  or 
enabled  to  exert  themselves  to  greater  mechanical  advantage  by  a 
framework — the  sJceleion. 

The  skeleton  consists  of  hones  {Ossa),  and  cartilages  (Cartila- 
g'mes\  which  are  more  or  less  closely  united  at  sutures  {Suturce),  or 
movable  upon  each  other  at  Artlir a  {^omi^  or  articulati(ms).  At  the 
arthra  and  at  some  of  the  sutures  the  undesirable  displacement  of 
tlie  parts  is  checked  by  bands  of  inelastic  fibrous  tissue — the  liga- 
ments {Ligamenta). 

Firmer  in  texture,  more  definite  in  outline,  and  more  constant  in 
form,  number  and  position  than  most  of  the  soft  parts,  the  bones 
and  cartilages  serve  as  convenient  guides  to  the  identification  and 
description  of  the  latter,  and  therefore  naturally  precede  them  as 
subjects  of  anatomical  study. 

The  following  general  account  of  the  skeleton  as  a  whole  is  given 
In  advance  of  the  detailed  description  of  the  individual  bones  in 
order  that  the  directions  for  certain  preliminary  operations  may  be 
more  easily  understood  and  followed. 

§  205.  Fig.  30.— The  skeleton  seen  from  the  left. 

This  figure  lias  been  reduced  by  photography  from  that  of  Straus-Durckheim  (A,  PI. 
11),  and  has  been  further  modified  as  follows  :  the  dextral  costsB  (ribs)  have  been  omitted 
for  the  sake  of  clearness  ;  the  last  costicartilage  has  been  shortened  so  as  to  show  its  actual 
condition  ;  the  principal  bones  have  been  named,  and  the  costss  and  vertebrae  have  been 
numbered  ;  the  shading  is  likewise  altered  somewhat. 

§  206.  Like  the  body  as  a  whole,  the  skeleton  comprises  a 
56>W(2<(/c  ("axial")  portion  including  the  bones  of  the  head^  necJc^ 
thorax,  abdomen,  pelvis  and  tail,  and  a  membral  ("appendicular") 
portion,  including  the  bones  of  the  arms  and  legs. 


88 


ANATOMICAL    TECHNOLOGY, 


THE    SKULL    AND     VERTEBRA.  89 

The  membral  bones  have  been  shown  from  the  dorsal  aspect  in 
the  normal  position  of  the  parts  in  Fig.  6,  but  in  Fig.  30  the  animal 
is  represented  from  the  left  side,  in  one  of  its  natural  attitudes  while 
standing  or  walking. 

In  this  attitude  the  limbs  are  directed  ventrad  instead  of  laterad, 
and  are  thus  nearly  parallel  to  each  other ;  while  their  segments 
and  the  general  divisions  of  the  somatic  skeleton,  the  head,  neck, 
trunk  and  tail,  form  angles  with  each  other,  imparting  to  the  whole 
skeleton  a  graceful  and  spirited  appearance. 

§  207.  Skull— (Fig.  56-62).— The  cephalic  division  of  the  so- 
matic skeleton  is  the  slcull^  consisting  of  the  cranium  or  brain- 
case,  and  the  face^  to  which  appertains  the  mandible  or  lower  jaw. 
The  transverse  ridge  at  the  junction  of  the  dorsal  and  caudal  as- 
pects of  the  skull  is  the  Crista  lamdoidalis  (Fig.  56,  Cst.  lmd.)\ 
the  darkly  shaded  area  between  the  cranium  and  the  face  repre- 
sents the  left  orhit^  and  the  longitudinal  irregular  bar  just  ventrad 
of  it  is  the  zygoma^  or  arcus  zygomaticus  (Fig.  56). 

•  The  Os  hyoides  will  be  described  in  §  224. 
§  208.  Vertebrae— (Fig.  51-55).— Caudad  from  the  skull  extends 
a  series  of  bony  segments— the  VertebrcB—Qon^tiiwimg  the  Columna 
Dertehralis  or  spine  or  spinal  column.  As  seen  from  the  side,  the 
Columna  presents  two  curvatures  in  opposite  directions,  like  an 
elongated  letter  s. 

For  convenience  and  more  or  less  naturally,  the  vertebrae  may 
be  grouped  in  live  divisions,  cermcal,  thoracic^  lumbar,  pelvic  or 
sacral  and  caudal.  The  numbers  following  the  names  of  these 
groups  upon  Fig.  30  are  those  which  are  most  commonly  observed, 
but  variations  sometimes  occur,  as  will  be  mentioned  in  the  descrip- 
tion of  the  Columna  vertebralis. 

^P    The  vertebrae  of  each  group  have  certain  features  in  common, 

^^nd  also  individual  peculiarities  by  which,  excepting  most  of  the 
caudales,  they  may  be  distinguished  when  completely  isolated. 
On  the  entire  skeleton,  the  groups  are  most  readily  recognized 
on  account  of  the  connections  of  three  of  them  with  other  parts,  as 

^follows : — 

^b  The  thirteen  thoracic  vertebrae  are  costiferous,  that  is,  connected 
with  the  ribs ;  the  cervical  series  begins  at  the  skull,  and  the  three 
sacral  vertebrae  are  united  so  as  to  form  a  single  bone — the  sa- 
crum— to  which  is  attached  the  Os  innomiuatum  on  either  side. 
The  lumbar  vertebrae  intervene  between  the  thoracic  and  the  sa- 


90  ANATOMICAL    TECHNOLOGY, 

crum,  while  the  caudal  vertebrae  extend  caudad  of  the  last-named 
bone. 

The  first  and  second  cervical  vertebrae  (Fig.  52),  are  also  called, 
respectively,  atlas  and  axis.  The  former  is  expanded  laterally  in 
wide  transverse  processes.  The  latter  presents  a  Sjdna  neuralis, 
which  is  both  long  and  high. 

The  seventh  cervical  spine  and  the  first  five  thoracic  are  hidden 
in  Fig.  30.  The  first  nine  or  ten  thoracic  spines  are  directed  more 
or  less  decidedly  caudad,  but  the  last  two  or  three,  like  the  lum- 
bar, are  directed  cephalad,  while  the  tenth  or  eleventh  has  an  inter- 
mediate dii-ection.  The  various  processes  become  less  and  less  dis- 
tinct among  the  caudal  vertebrae,  and  the  caudal  members  of  the 
series  are  little  more  than  subcylindrical  segments  of  bone. 

Unlike  most  anatomists,  Straus-Durckheim  includes  (B,  I.,  480,  PI.  xi.,  B,  C),  the 
eleventh,  twelfth  and  thirteenth  thoracic  vertebraB  with  the  lumbar  series. 

§  209.  Costse — (Fig.  50). — Each  casta  (rib)  is  seen  to  be  con- 
nected by  its  dorsal  end  with  the  thoracic  region  of  the  Columna 
xertehralis^  and  at  its  ventral  with  a  costicartilago.  Part  of  the  first 
costi cartilage  appears  in  Fig.  30  just  cephalad  of  the  left  shoulder 
joint,  but  the  second  rib  and  its  cartilage  are  wholly  concealed  by 
the  scapula  and  humerus. 

§  210.  Sternum — (Fig.  49). — The  sternum^  or  breast-bone,  con- 
sists of  a  series  of  eight  or  nine  mesal  segments  called  sternehrce. 
The  caudal  piece  is  the  xiphisternum  or  Ctl.  ensiformis^  and  is 
partly  cartilaginous.  The  cephalic  segment  is  the  prcesternum  or 
manubrium,  and  the  intervening  six  or  seven  sternebrae  constitute 
the  meso sternum. 

%  211.  Scapula  — shoulder  blade— (Fig.  43-45).— The  ectal  as- 
pect of  this  bone,  as  shown  in  Fig.  30  and  44,  presents  a  ridge, 
the  mesoscapula,  which  has  three  prominences — acromion^  meta- 
cromion^  and  tuberositas. 

§  212.  Clavicula — The  clavicle  or  collar  bone— (Fig.  48).— In 
the  cat  these  bones  are  small  and  imbedded  in  the  muscles,  with- 
out direct  attachment  to  other  bones.  They  are  shown  in  Fig.  30, 
one  on  each  side,  between  the  shoulder  joints. 

A.  In  the  cat  the  scapula  appears  as  a  part  of  the  arm.  In  man,  however,  and  in  many 
other  vertebrates,  the  clavicles  are  larger  and  articulated  with  the  scapulae  and  the 
sternum.  In  most  reptiles  and  birds,  and  in  two  Mammals  {Echidna  and  OrnitJwrhynchus) 
the  scapula  and  the  sternum  are  connected  by  a  stout  oss3ous  bar — the  coracoid — which  is 
represented  in  the  cat  as  in  man  by  merely  a  process — the  Pre.  coracoideua  ;  Fig.  43,  45. 


i 


ANTAG0yiS3f    OF    THE    MEMBRAL    SEGMENTS.  91 

B.  The  two  scapulae  vvitli  the  clavicles  and  the  coracoiJ  bones  are  commonly  regarded 
as  constituting  a  sort  of  belt — the  scapular  arch  or  shoulder  girdle. 

§  213.  Pelvis— Pelvic  Girdle— (Fig.  51).— This  limb  girdle  is 
complete  in  the  cat.  Each  lateral  piece — Os  iiinqminatum — is  at- 
tached to  the  sacrum  by  its  dorsal  end,  and  ventrad  joins  its 
platetrope  (fellow  of  the  opposite  side)  at  the  symphysis  pubis. 
Th?  rounded  vertebral  end  of  each  os  innominatum  is  the  Crista 
illi^  and  the  caudal  end  is  the  iscMatic  tuberosity. 

%  214.  Shoulder  and  Hip  Joints. — These  are  the  proximal  arthra 
of  the  arm  and  the  leg  respectively,  forming  their  points  of  attach- 
ment with  the  shoulder  girdle  and  the  pelvis.  Both  are  ball-and- 
socket  joints,  but  the  former  is  the  more  free,  and  the  position  of 
the  entire  joint  may  be  changed  on  account  of  the  suspension  of 
the  scapula  in  the  muscles. 

§  215.  Elbow  and  Knee. — These  are  Ibotli  hinge  joints,  the  lat- 
ter being  less  encompassed  by  bone,  and  hence  somewhat  the  freer 
of  the  two.  At  the  knee  the  femur  articulates  with  the  tibia  only, 
while  the  elbow  is  between  the  humerus  and  both  the  ulna  and 
adius. 

§  216.  Wrist  and  Ankle. — The  latter  is  a  true  hinge  joint,  but 
the  former  combines  features  of  the  hinge  and  the  ball-and-socket 
varieties. 

§  217.  The  Bones  of  the  Limbs. — All  of  these  have  been  named 
in  the  Introduction  in  connection  with  the  description  of  Fig.  6 
(§§  82-85),  and  some  will  be  described  hereafter  with  more  detail. 
Reference  will  be  made  here  only  to  certain  general  features  of  the 
larger  bones,  and  to  the  attitudes  of  the  entire  limbs. 

Antagonism  of  tlie  Membral  Segments. — It  will  be  noted  that, 
excepting  the  distal  segments,  the  corresponding  segments  of  the 
limbs  point  in  opposite  directions,  and  that  the  same  antagonism 
exists  between  the  principal  elements  of  the  scapular  arch  and 
the  pelvic  girdle.  As  a  necessary  concomitant,  any  two  successive 
segments^  excepting  in  the  case  of  the  manus  and  antehrachium^ 
point  in  opposite  directions. 

From  this  relation  of  the  segments  there  are  two  results  :  First, 
that  the  weight  of  the  body  rests  upon  columns  which  are  not  only 
near  its  opposite  ends,  but  also  tend  to  counteract  each  other  for  the 
most  part,  so  that  stability  is  more  easily  maintained.  Neverthe- 
less, by  exception,  the  distal  segments  coincide  in  direction,  so  that 
both  limbs  may  strike  the  ground  in  one  direction,  and  thus  propel 


92  ANATOMICAL     TECHNOLOGY. 

the  bodv  in  the  other.  Second,  these  limbs  are  more  elastic  than  if 
the  several  segments  were  in  the  same  line,  and  the  muscles  act 
upon  the  bones  to  better  mechanical  advantage. 

§  218.  By  some  writers  (Wyman,  75,  253;  Coues,  1,  15),  and  formerly  by  the  senior 
author  (5,  45),  this  opposed  or  symmetrica]  or  aatitropic  relation  of  the  scapula  and 
ilium,  and  of  the  propodial  and  epipodial  bones  of  the  arm  and  leg  has  been  repfarded 
as  evidence  in  favor  of  a  general  symmetrical  Jiomology  between  the  two  limbic  The 
senior  author,  however,  has  admitted  (lO,  15)  that  this  antagonistic  relation  is  secondary 
and  telical  rather  than  primary  and  morphical,  and  has  fully  assented  to  the  view  that  in 
their  normal  position  both  pairs  of  limbs  extend  laterad  from  the  trunk,  and  their  flexures 
are  in  the  dorso- ventral  rather  than  in  the  cephalo-caudal  direction. 

§  219.  To  replace  the  limbs  in  their  normal  and  primitive  posi- 
tion (see  §  45),  it  is  necessary  to  rotate  the  elbow  cephalad  and  the 
knee  caudad,  and  then — if  the  commonly  accepted  view  be  correct — 
to  lateriduct  both  limbs  until  they  are  at  right  angles  with  the 
meson,  as  in  Fig.  6. 

This  rotation  will  leave  the  convexities  of  the  elbow  and  the  knee 
facing  dorsad  (as  in  Fig.  7),  and  that  of  the  ankle,  with  the  plantar 
aspect  of  the  pes,  facing  ventrad.  In  the  arm,  however,  the  corres- 
ponding aspect  of  the  manus — the  palm — will  be  left  facing  dorsad, 
and  the  ulna  and  radius  will  be  crossed  instead  of  parallel  like  the 
corresponding  tibia  and  fibula.  But  if  the  manus  be  supinated, 
the  ulna  and  radius  will  be  parallel,  and  the  palm  will  face  ventrad 
like  the  sole. 

The  restoration  just  described  is  assumed  to  have  taken  place  in 
the  following  brief  account  of  some  of  the  bones  and  their  promi- 
nences : — 

§  220.  The  proximal  end  of  the  humerus  presents  an  elevation, 
the  trocMter  or  Tuberositas  major  (Fig.  45,  46),  which  is  cephalic 
in  the  normal  position  of  the  parts,  but  lateral  in  their  natural  atti- 
tude. At  the  distal  end  of  the  same  bone  (Fig.  46)  are  two  eleva- 
tions, the  epicondylus  and  epitrocJilea^  commonly  called  external 
and  internal  condyles.  In  the  natural  attitude,  as  seen  in  Fig.  30, 
the  epicondyle  shows  on  the  left  arm,  and  the  epitrochlea  on  the 
right. 

The  ulna  projects  dorsad  and  proximad  of  the  elbow  as  a  thick 
process,  the  olecranon.  Just  distad  of  the  joint,  on  the  ventral  side 
of  the  bone,  is  an  elevation— the  Processus  coronoideus—for  the 
attachment  of  the  M.  hrachialis. 

The  proximal  end  of  the  radius  is  the  capitellum,  while  the  distal 
end  of  each  antebrachial  bone  presents  a  short  Pre.  styloideus. 


THE    POSITIONS    OF    THE    ARTHBA.  93 

The  individual  carpalia  are  not  easily  distinguished,  but  the  0. 
pisiforme  is  seen  on  the  right  side  ;  see  Fig.  47. 

§  221.  At  the  proximal  end  of  ^h^  femur  is  a  marked  process, 
the  trochanter^  which  is  naturally  visible  in  the  lateral  view  of  the 
bone,  but  normally  has  a  caudal  position.  At  the  distal  end  of  the 
same  bone  are  the  cephalic  and  caudal  (''inner  and  outer")  con- 
dyles. 

At  the  convexity  of  the  knee,  and  thus  normally  dorsad  of  the 
joint,  is  i\ie  patella^  which  answers  in  some  respects  to  the  olecranon, 
but  is  really  only  a  very  large  0.  sesamoideum. 

The  tibia  is  seen  to  be  both  larger  and  longer  than  the  fibula, 
which  indeed  does  not  enter  into  the  composition  of  the  knee.  The 
malleoli^  cephalic  and  caudal  {internal  and  external)^  are  slight 
(elevations  of  the  distal  ends  of  the  tibia  and  fibula  respectively.  Of 
the  tarsalia,  the  prominent  calcaneum  is  easily  recognized. 

§  222.  In  ordinary  locomotion  neither  the  palm  nor  the  sole  are 
in  contact  with  the  ground  excepting  at  the  junction  of  the  metacar- 
pal and  metatarsal  regions  with  the  digits  and  dactyls ;  the  body  is 
supported  upon  the  ball  of  the  foot  and  the  dactyls  and  upon  the 
corresponding  parts  of  the  manus,  and  the  cat  is  thus  a  typical 
digitigrade.  We  can  imitate  its  condition  so  far  as  concerns  the 
elevation  of  the  heel  and  the  support  of  the  body  mainly  upon 
the  ball  of  the  foot ;  but  the  human  digits  and  dactyls  can- 
not be  brought  into  the  state  of  the  cat's,  where  the  proximal 
phalanges  are  flexed  dorsad,  the  intermediate  ventrad,  and  the 
distal  ones  again  dorsad  so  as  to  keep  the  sharp  claw  points  off 
the  ground. 

§  223.  The  Positions  of  the  Arthra.— It  will  be  noted  that  the 
arthra  of  the  arm  are  ventrad  of  the  corresponding  arthra  of 
the  leg,  although  the  manus  and  pes  are  upon  the  same  plane, 
and  the  vertebral  ends  of  the  scapula  and  ilium  are  at  nearly  the 
same  level. 

Since  there  is  little  difference  in  either  length  or  inclination 
between  the  humerus  and  femur,  and  the  radius  and  tibia,  this 
difference  in  the  levels  of  the  arthra  must  be  associated  with  the 
greater  length  of  the  pes  as  compared  with  the  manus,  and  with  both 
the  length  and  more  nearly  vertical  direction  of  the  scapula  as  com- 
pared with  the  ilium. 

Notwithstanding  the  popular   designation  of  the  wrist  of  a  horse  as  its  "  knee,"  it 
should  be  kept  in  mind  that  the  true  knee  of  the  mammalian  quadruped  is  a  joint 


94  ANATOMICAL    TECHNOLOGY. 

of  the  leg,  and,  like  its  counterpart  the  elbow,  is  but  slightly  removed  from  the  level 
of  the  ventral  border  of  the  trunk.  The  ankle  of  the  quadruped  is  often  called  Jiongh 
or  hock. 

§  224.  Os  Hyoides  and  Larynx — (Fig.  30). — Dependent  from 
the  caudal  region  of  the  basis  cranii  is  an  inverted  segmented 
bony  and  cartilaginous  arch — the  Os  hyoides.  Connected  with 
the  summit  or  ventral  end  of  this  arch  is  the  laryjtx,  a  cartilagi- 
nous case  forming  the  principal  organ  of  the  voice.  (In  Fig.  30  the 
larynx  is  placed  too  nearly  in  contact  with  the  fifth  Vertebra  cer- 
mcalis). 

The  keystone  of  the  arch  appears  in  Fig.  30  only  by  its  sinistral 
end,  shown  as  a  small  subquadrate  area  close  to  the  angle  formed 
by  the  junction  of  the  ventral  outlines  of  the  head  and  the  neck. 
The  lateral  bar  extending  from  this  point  caudad  and  slightly 
ventrad  is  one  of  a  pair  of  pieces  called  thyro-hyals^  which  are 
additions  to  the  arch  itself,  and  are  most  directly  connected  with 
the  larynx. 

Each  lateral  half  or  pier  of  the  arch  consists  of  four  segments,  as 
follows : — 

Next  to  the  basihyal  is  the  cerato-hyal.  Then  comes  the 
epiJiyal.,  and  then  the  stylo-Tiyal.  In  the  figure  the  dotted  line 
from  the  words  os  Tiyoides  is  drawn  to  the  arthron  between  the 
cerato-hyal  and  epihyal.  The  three  pieces  mentioned  are  bony  ; 
the  fourth  piece,  which  appears  in  the  figure  along  the  side  of  the 
bidla.,  is  cartilaginous,  and  has  been  called  Ctl.  stylo-liyoidea.  It 
is  attached  at  the  bottom  of  a  deep  pit  just  laterad  of  the  bulla  ; 
(see  Fig.  57,  Fs.  tyh.).  The  sequence  of  the  osseous  segments  may 
be  connected  with  the  alphabetical  order  of  the  initials  of  their 
names,  B^  C,  E.,  and  8. 

A.  For  fuller  accounts  of  the  Os  hyoides,  and  for  the  origin  of  the  names  of  the  seg 
ments,  consult  Owen,  A,  II.,  506  ;  Flower,  A,  123.  Straus-Durckheim's  account  (A,  I,  450- 
453)  is  not  very  satisfactory.  The  figures  of  Mivart  (B,  78)  are  good,  but  he  asciibes  to 
the  cat  a  small  osseous  segment — the  tym'pano-hyal — which  exists  in  the  dog  (Flower,  A, 
123),  but  which  we  have  failed  to  find  in  even  old  cats,  and  which  is  not  mentioned  by 
Straus-Durckheim. 

B.  In  man  the  thyro-hyals  are  disproportionately  large,  and  are  called  the  greater 
corrma,  while  the  cerato-hyals  are  called  lesser  cornua.  Quain,  A,  I,  55  ;  Gray,  A,  206  ; 
Parker  and  Bettany,  A,  305. 

The  following  parts  of  the  larynx  may  be  recognized  in  the 
figure : — 

The  largest  and  ventrally  placed  piece,  and  that  which  is  reached 


ANATOMICAL     LAyDMARKS.  95 

by  the  dotted  line,  is  the  Ctl.  tJiyroidea.  In  man  it  forms  the  mesal 
j)rojection  known  as  '^  Adam's  apple."  Jnst  ventrad  of  it  in  the 
ligure,  but  caudad  in  the  normal  position  of  the  parts,  is  the  ring 
shaped  Ctl.  cricoidea.  Each  thyro-hyal  segment  of  the  Os  hyoides 
is  directly  connected  with  the  larynx  by  a  small  Ctl,  arytenoidea, 
one  of  which  is  indistinctly  shown  in  the  figure  at  the  dorsal  (really 
cephalic)  end  of  the  prolongation  of  the  Ctl.  cricoidea.  The  epi- 
glottis is  seen  projecting  just  dorsad  of  the  thyro-hyals. 

ANATOMICAL  LANDMARKS. 

§  225.  During  dissection  and  experimentation  it  is  often  de- 
sirable to  determine  the  lines  and  limits  of  incisions,  or  to  ascertain 
tlie  location  and  outline  of  parts  which  are  obscured  by  the  skin  or 
other  soft  parts.  The  elevations  and  depressions  which  may  serve 
as  guides  are  called  anatomical  landmarks. 

The  landmarks  liere  described  should  be  carefully  studied,  first  upon  the  prepared 
skeleton  by  the  aid  of  figures  and  descriptions,  and  then  npon  the  entire  cat  by  the  aid  of 
preparations  of  the  soft  parts,  and  frozen  sections  and  dissections. 

Most  of  the  landmarks  are  more  easily  recognized  upon  the  living  or  freshly  killed 
animal,  but  they  should  be  sought  also  during  the  continuance  of  rigor  mortis,  and  upon 
specimens  hardened  by  alcohol.  Finally,  their  recognition  should  be  practised  also  with 
the  eyes  closed. 

Whoever  intends  to  perform  experiments  should  become  sufficiently  intimate  with 
some  cat  to  be  permitted  to  manipulate  all  the  accessible  parts.  The  late  Prof,  Jeffries 
Wyman  once  told  the  senior  author  that  in  Paris  he  lived  in  the  same  house  with  Straus- 
Durckheim  ;  and  that  the  indefatigable  felitomist  would  sometimes  sit  by  the  hour  holding 
a  cat,  and  passing  his  fingers  from  point  to  point  over  the  muscular  elevations,  the  joints 
and  other  bony  prominences  with  which  his  mind  was  occupied  at  that  time. 

The  landmarks  form  three  groups,  mesal  somatic,  lateral  so- 
matic, and  memhral. 

%  226.  Mesal  Somatic  Landmarks  —  Crista  lambdoidalis — 
(Fig.  ^^). — Prominent  as  is  this  crest  upon  the  prepared  skull,  it  is 
by  no  means  easy  to  find  upon  the  entire  animal.  The  cervical 
muscles  just  caudad  of  the  occiput  are  very  firm  and  compact,  so 
that  the  change  of  siibstance  is  not  very  marked  to  the  touch. 
The  crista,  however,  is  nearly  in  a  line  with  the  most  caudal  con- 
vexity of  the  ears,  and  may  be  more  distinctly  felt  during  alternate 
ventriduction  and  dorsiductidn  of  the  head. 

§  227.  Spina  Neuralis  Axialis — The  axial  spine — (Fig.  30). — The 
somewhat  sharp  caudal  projection  of  this  spine  may  be  felt  at  the 
dorsimeson  between  the  cervical  muscles  3-4  cm.  from  the  Crista 
lambdoidalis,  and  not  far  from  the  scapulse. 


96  ANATOMICAL    TECHNOhOGT. 

Spina  Newalls  Thoracica  Prima — The  first  thoracic  spinous 
process. — This  is  about  half  as  long  again  as  that  of  the  seventh 
cervical  vertebra,  and  larger  at  the  tip  ttian  the  succeeding  thoracic 
spines.  In  the  living  animal,  it  is  at  the  bottom  of  the  interscapular 
depression,  but  one  or  both  of  the  scapulae  may  be  ventriducted  so 
as  to  leave  it  more  prominent. 

In  miin,  it  is  the  seventli  cervical  spine  which  is  longer  than  the  rest,  whence  the 
name  F^sr^e&rtt  pro wi/ze^is  sometimes  applied  to  the  vertebra. 

8p.  Nrl.  Thr.  lS—(^\g.  30).— This  is  a  little  cephalad  of  the 
vertebral  ends  of  the  last  ribs,  and  may  sometimes  be  distinguislied 
from  the  other  thoracic  spines  by  its  greater  cephalo-caudal  extent, 
wherein  it  resembles  the  lumbar  series.  The  tenth  or  eleventh  spine 
is  usually  quite  short,  so  as  to  leave  a  slight  hiatus  about  2  cm. 
cephalad  of  the  thirteenth.  In  counting  the  spines  beginning  with 
the  first,  the  thirteenth  will  usually  appear  to  be  the  twelfth  on 
account  of  the  short  one  just  mentioned.  If  the  lumbar  series  be 
counted,  attention  must  be  paid  to  the  point  next  mentioned. 

Spina  Lumbalis  7 — The  last  lumbar  spine. — This  projects  just 
cephalad  of  a  line  between  the  Cristse  iliorum,  while  the  first  sacral 
spine  projects  between  the  Cristse,  so  as  to  be  hidden  by  them  in 
the  figure  of  the  entire  skeleton  (Fig.  30). 

§  228.  Pubes — (Fig.  51). — The  cephalic  border  of  the  pubic  bone 
is  easily  felt  both  at  and  laterad  of  the  ventrimeson. 

Epigastrium  and  Xiphisternum — (Fig.  72). — The  ej)igastrium  is 
a  subtriangular  area  at  about  the  junction  of  the  cephalic  and 
middle  third  of  the  trunk.  Its  latero-cephalic  borders  are  formed 
by  the  ninth  and  tenth  costicartilagines.  The  xiphisternum  (Fig. 
30,  49,  72,)  may  be  felt  on  the  meson  in  a  lean  cat,  bat  it  is  some- 
times obscured  by  fat. 

Prcesternum — (Fig.  30,  49). — This  is  easily  distinguished  either 
on  passing  the  finger  cephalad  along  the  sternum  to  the  neck,  or 
caudad  along  the  neck  until  it  reaches  the  somewhat  sharply  pro- 
jecting point. 

Larynx  —  (Fig.  30). — This  forms  a  compressible  ventrimesal 
prominence  about  midway  between  the  prsesternum  and  the  chin 
when  the  head  is  dorsiducted  so  as  to  bring  the  ventral  surface  of 
the  neck  and  head  into  the  same  plane. 

Lateral  Somatic  Landmarks. — These,  of  course,  are  in  pairs, 
but  they  will  be  spoken  of  in  the  singular  number. 


MEMBRAL    LANDMARKS,  9? 

§  229.  Zygoma — The  Arcus  zygomaticus— (Fig.  30,  56).— Both 
the  dorsal  and  ventral  borders  of  this  may  usually  be  felt  distinctly, 
although  in  old  males  it  is  more  or  less  obscured  by  the  thickness 
of  the  skin  and  connective  tissue  upon  the  cheeks.  The  dorsal 
border  is  nearly  in  line  with  the  lateral  angle  of  the  eye. 

Dlapophysls  atlantalis — Transverse  process  of  the  atlas  verte- 
bra— (Fig.  30,  53). — This  may  be  felt  as  a  ridge  just  caudad  of  the 
base  of  the  ear.  The  caudal  angle  is  more  distinct,  and  the  soft 
parts  on  its  ventral  side  are  less  prominent  and  firm  than  those  upon 
the  dorsal. 

Scapula — (Fig.  30,  44). — The  middle  of  the  convex  vertebral 
margin  of  the  scapula  projects  dorsad  of  the  intervening  cervical 
neural  spines,  so  as  to  give  rise  to  the  Depressio  inter scapularis 
which  is  so  marked  while  the  living  cat  is  on  its  feet.  Upon  a  lean 
animal,  the  following  scapular  prominences  may  be  easily  deter- 
mined :  mesoscapula^  with  its  tuberosity  (Fig.  44) ;  glenO'Vertebral 
angle  (Fig.  43) ;  (the  coraco-mrtebral  angle  is  so  heavily  overlaid 
with  muscle  as  to  be  less  easily  felt) ;  acromion  (Fig.  44,  45) ; 
metacromion. 

§  230.  Costa  i^— Last  rib. — The  abdominal  parietes  just  caudad 
of  the  last  rib  are  easily  indented  by  the  finger  almost  to  the  apex 
of  the  triangular  area  which  intervenes  between  it  and  the  lateral 
border  of  the  vertebral  muscles  (Fig.  30). 

Crista  ilii. — When  the  finger  is  carried  along  the  border  of  the 
vertebral  muscles  at  about  the  same  distance  from  the  meson  as  the 
apex  of  the  angle  between  them  and  the  last  rib,  the  Crista  ilii  is 
felt  as  a  rounded  ridge  nearly  dorsad  of  the  knee  (Fig.  51). 

Tuberositas  ischii — Ischiatic  tuberosity. — This  is  felt  as  a  blunt 
prominence  ventro-laterad  of  the  anus. 

Clavicula—The  clavicle  or  collar  bone— (Fig.  30,  48,  67,  72).— In 
young  or  lean  animals  this  may  be  felt  by  pinching  up  the  skin 
and  subjacent  muscles  between  the  shoulder  and  the  prsestemum. 

Membral  Landmarks. — These,  likewise,  are  in  pairs,  but  are 
spoken  of  in  the  singular  number. 

§  231.  Arthra. — After  what  has  been  said  in  the  general  descrip- 
tion of  the  skeleton  (§§  214-223),  there  will  be  no  difficulty  in  ascer- 
taining the  position  of  any  of  the  membral  arthra.  Most  of  the 
bony  prominences  also  may  be  recognized  readily  from  their  rela- 
tions to  the  arthra. 

-     Troc7iiter—(Fig.  30, 46)— The  greater  tuberosity  of  the  humerus.— 
7 


yb  ANATOMICAL     TECHNOLOGY. 

This  forms  a  marked  projection  at  the  convexity  of  the  shoulder, 
a  little  ventro-cephalad  of  the  acromion. 

Olecranon^  Epicondyliis  and  Epitroclilea—i^ig,  30,  46).— These 
prominences  about  the  elbow  joint  are  recognized  without  difficulty 
even  in  fat  animals  4f  the  parts  are  manipulated  between  the  thumb 
and  lingers. 

M.  biceps— (Fig.  74,  75).— The  fusiform  body  of  this  muscle  may 
be  felt  on  the  ventral  aspect  of  the  antebrachium  by  rolling  the  soft 
parts  gently  between  the  fingers  upon  the  humerus.  It  is  less  dis- 
tinct than  in  man,  on  account  of  the  more  distal  extension  of  the 
insertion  lines  of  the  pectoralis  group  of  muscles. 

§  232.  Capitellum  radii—Head  of  the  radius.— By  alternately 
pronating  and  supinating  the  manus  while  a  finger  is  pressed  upon 
the  elbow  a  little  ventro-distad  of  the  epicondylus,  the  capitellum 
may  be  felt  during  its  rotation. 

Processus  styloides  ulnce  et  radii — The  styloid  processes  of  the 
ulna  and  radius. — These  are  to  be  felt  at  the  caudal  and  cephalic 
sides  of  the  wrist  joint. 

Os  pisiforme—(F\g.  30).— This  forms  a  marked  and  somewhat 
movable  projection  just  proximad  of  the  wrist,  and  on  the  caudo- 
ventral  border  of  the  antebrachium.  Just  distad  of  it  is  a  promi- 
nent callosity — ^the  Tiypothenar  eminence  (Fig.  105). 

§  233.  7Voc^(5^7z/er— Trochanter  major  femoris — (Fig.  30). — This 
projects  considerably  from  the  hip,  a  little  ventrad  of  a  line  between 
the  Crista  ilii  and  the  Tuberositas  ischii,  and  a  little  nearer  the 
latter.     Its  movement  is  distinct  when  the  leg  is  moved. 

Patella — The  knee  pan. — When  the  crus  is  extended  so  as  to 
relax  the  muscles  connected  with  the  patella,  this  bone  is  easily 
moved  from  side  to  side. 

Calcaneum. — This  forms  the  marked  projection  on  the  ventral 
aspect  of  the  leg  just  proximad  of  the  ankle  ;  it  is  sometimes  called 
the  hock. 

Malleoli. — These  processes  of  the  distal  ends  of  the  tibia  and 
fibula  are  readily  distinguished  at  the  cephalic  and  caudal  sides  of 
the  ankle. 

ABDOMINAL  TRANSECTION. 

§  234.  Since  most  of  the  dissections  herein  described  involve 
only  the  thorax,  neck,  head  and  arms,  it  is  usually  more  convenient 
and  economical  to  divide  the  body  into  caudal  and  cephalic  parts. 


ABDOMINAL    TRANSECTIOX.  99 

The  former  may  then  be  thrown  away,  and  the  latter  preserved,  or 
dissected  while  fresh.  The  kidneys  are  important  visceral  land- 
marks, and  are  easily  preserved,  hence  they  may  be  retained  with 
the  cephalic  part. 

Abdominal  transection  may  be  performed  alone,  but  it  is  more 
conveniently  done  when  another  person  holds  the  cat  in  the  desired 
positions.  The  assistant,  also,  may  read  the  directions  to  the 
operator. 

§  235.  Instruments  and  Materials.  —  Arthrotome  ;  tracer ; 
medium  scalpel ;  coarse  curved  scissors ;  hair  scissors ;  block ; 
twine,  about  half  a  meter ;  skeleton  ;  wide  mouthed  jar  (about 
6x12,  15  or  18  in.) ;  alcohol,  52-67  per  cent.,  to  half  fill  the  jar; 
coarse  syringe  ;  large  tray. 

§  236.  Parts  Involved. — The  following  parts  are  more  or  less 
directly  involved  in  Abdominal  Transection.  From  the  figures  and 
sections  referred  to,  enough  should  be  learned  to  enable  the  operator 
to  recognize  them  during  the  operation : — 

Aorta,— ¥\g,  101. 

Columna  Vertebralis, — The  spinal  column. 

CostcB—R\b^,—F\g,  30,  50,  73. 

Costicartilagines — The  costal  cartilages. — Fig.  30,  50. 

Crista  ilii — The  crest  of  the  ileum. — Fig.  30,  51. 

BiapJiragma — The  diaphragm. — Fig.  90,  101. 

Epigastrium— "IhQ  ''pit  of  the  stomach."— Fig.  30,  72. 

Fihro-cartilago  inter vertehralis — The  (sixth  lumbar)  interverte- 
bral disk  of  fibro-cartilage. — Fig.  51. 

Hepar — The  liver. — Fig.  77. 

Intestinum  Tenue — The  small  intestine. — Fig.  77. 

Ligamentum  Buspensorium  Hepatis — The  suspensory  liga- 
ment of  the  liver. 

Mesenterium. — Fig.  78. 

(Esophagus— The  gullet. — Fig.  107. 

Parietes  Abdominales — The  abdominal  parietes,  the  muscular 
and  membranous  lateral  and  ventral  walls  of  the  abdomen. — Fig. 
77,  101. 

P elms— The  pelvic  girdle.— Fig.  30,  51. 

Postcava — Vena  cava  inferior  s>  ascendens. — Fig.  101. 

Rectum, — Fig.  77. 

Renes—The  kidneys.— Fig.  79,  101. 
_     8tomachus—'Y\iQ  stomach.— Fig,  78,  81. 


100  ANATOMICAL    TECHNOLOGY. 

ThoraX'-l^hQ  chest.— Fig.  30,  77. 

Yertebrce  lumbales — The  lumbar  vertelbrse,  with  their  diapo- 
physes  and  zygapophyes. — Fig.  30,  51,  55. 

XipTiuternum — The  ensiform  cartilage  of  the  sternum. — Fig. 
30,  49. 

§  237.  Operation. — Place  the  cat  dorsicumbent,  the  head  to  the 
left.  Pinch  up  the  right  abdominal  parietes  about  midway  be- 
tween the  crista  ilii  and  the  last  rib. 

With  the  arthrotome,  transfix  the  fold  so  pinched  up,  and  cut 
ento-ectad  to  the  surface.  If  only  the  skin  is  divided  at  the  first 
attempt,  pinch  up  the  muscles  and  repeat  the  transfixion,  but  be 
careful  not  to  include  any  of  the  intestines  within  the  fold. 

Into  the  incision  so  made,  insert  the  left  index  and  medius,  the 
hand  being  supinated,  and  lift  the  parietes  away  from  the  viscera. 
Introduce  the  scalpel,  with  the  edge  directed  ectad,  and  divide  the 
parietes  on  each  side  until  the  thicker  vertebral  muscles  are  reached 
a  few  centimeters  from  tlie  dorsimeson.  The  dorsal  ends  of  this 
transverse  incision  should  be  just  caudad  of  the  Mdneys. 

About  2  cm.  sinistrad  of  the  ventrimeson,  divide  the  parietes 
longitudinally  to  the  pelvis  and  the  epigastrium,  making  sure  not 
to  cut  the  xipMsternum  or  costicartilages. 

Turn  aside  the  four  rectangular  flaps  so  formed,  and  draw  the 
intestines  caudad.  Introduce  the  pronated  left  hand  between  the 
liver  and  the  parietes  until  the  fingers  are  met  by  the  diapJiragm. 
Partly  flex  the  fingers,  and  push  them  somewhat  dorsad ;  then  draw 
the  liver  and  stomach  caudad  ;  this  will  expose  the  Tendo  centralis 
of  the  diaphragm,  which  should  be  punctured  with  the  tracer.  The 
admission  of  air  into  the  thorax  vdll  permit  the  farther  caudiduction 
of  the  liver  and  stomach. 

§  238.  If  the  cephalic  part  is  to  be  preserved,  ligate  the  rectum  and  then  the  stomach 
and  liver,  and  inject  84-95  per  cent,  alcohol  into  the  aorta,  as  directed  in  §  285.  After  two 
hours  a  plaster  injection  may  be  made  if  desired.     Then  proceed  as  in  §  239. 

If  the  parts  are  to  be  dissected  fresh,  or  if  the  muscles  are  to  be  exposed  and  the  thorax 
opened  so  soon  as  to  render  the  alcohol  injection  unnecessary,  proceed  as  in  §  239. 

§  239.  Insert  the  curved  scissors,  keeping  the  convexity  toward 
the  diaphragm,  and  divide  the  Ligamentum  suspensorium  of  the 
liver,  the  postcava  and  the  abdominal  oesopJiagus  \  while  so  doing, 
the  viscera  should  be  drawn  ventrad  as  well  as  caudad,  so  as  to  put 
the  parts  named  upon  the  stretch. 


PRESERVATION    AND    LABELING.  101 

When  the  liver  and  stomach  are  free,  draw  them  and  the  intes- 
tines caudad,  dividing  the  mesal  peritoneal  attachments  (mesente- 
rium)  to  a  point  ^-^  cm.  caudad  of  the  kidneys,  but  do  not  remove 
the  latter. 

Compress  the  rectum  between  the  fingers  so  as  to  force  its  con- 
tents in  both  directions  ;  ligate  it  in  two  places  about  2  cm.  apart, 
and  cut  between  the  ligatures  (Fig.  41).  The  viscera  thus  freed  may 
be  thrown  away  unless  wanted  for  some  purpose. 

§  240.  Place  the  block  under  the  cat  opposite  the  kidneys.  Press 
upon  the  thick  muscles  just  caudad  ot  the  kidneys,  and  about  2  cm. 
laterad  of  the  meson.  The  sixth  lumhar  diapopJiyses  (see  Fig.  30) 
will  be  felt.  With  the  arthrotome,  divide  all  the  soft  parts  on  the 
ventral  aspect  of  the  lumbar  vertehrce  between  the  tips  of  the  sixth 
diapophyses,  and  scrape  them  caudad  for  about  2  cm.  This  will 
expose  a  transverse  whitish  swelling,  the  inter  vertebral  fibro-carti- 
lage  between  the  sixth  and  seventh  lumbar  vertebrae. 

If  the  kidneys  are  not  to  be  kept,  or  if  it  is  desirable  to  make  tbe  whole  preparation 
shorter,  the  columna  vertebralis  may  be  divided  between  the  second  and  third  or  third  and 
fourth  lumbar  vertebrae. 

Push  the  arthrotome  into  this  fibro-cartilage,  and  cut  dextrad 
and  sinistrad  as  far  as  possible.  Then  cut  latero-cephalad  on  each 
side  to  the  tip  of  the  diapophysis ;  then  directly  laterad  so  as  to 
divide  the  thick  vertebral  muscles. 

Grasp  the  cephalic  part  of  the  cat  just  cephalad  of  the  incision, 
and  lift  it  from  the  tray.  If  this  does  not  disjoint  the  zyg apophyses^ 
bend  the  caudal  part  downward  until  the  ligaments  give  way,  and 
the  zygapophyses  are  separated.  Cut  the  remaining  soft  parts  and 
the  skin,  and  thus  complete  the  transection.  The  caudal  part  may 
be  thrown  away. 

Knead  the  thorax  so  as  to  expel  the  blood,  place  the  cephalic 
part — which  may  be  spoken  of  now  as  the  cat — upon  a  clean  dry 
tray,  or  upon  paper  laid  in  a  tray,  and  remove  the  hair,  as  directed 
in  Chap.  YI. ;  note  the  precautions  as  to  the  disposal  of  hair,  §  197. 

§  241.  Preservation. — Tie  the  twine  firmly  about  the  last  lum- 
bar vertebra  (which  is  the  sixth  if  the  directions  have  been  fol- 
lowed), and  make  a  loop  through  which  may  be  passed  a  second 
piece  of  twine  already  attached  to  the  ring  of  the  jar  cover,  or, 
better,  an  S-hook  connected  with  the  cover  by  a  string  of  suitable 
length.  To  the  vertebra  should  also  be  tied  a  tag  bearing  the  brief 
record  of  the  sex  of  the  cat,  its  age  or  apparent  period  of  growth, 


102  ANATOMICAL    TECHNOLOGY. 

its  color^  the  date  of  killing,  and  tlie  name  or  initials  of  the  dis- 
sector ;  a  similar  tag  should  be  attached  to  the  jar.  The  cat  may 
then  be  suspended  in  the  jar  head  downward  ;  all  parts  should  be 
immersed  in  the  alcohol.  If  any  parts  press  closely  against  the 
sides,    some  cotton  or  "excelsior"  should  be  interposed. 

If  the  cat  can  be  left  in  the  alcohol  for  at  least  a  week,  the  parts 
are  more  completely  and  uniformly  hardened. 

§  242.  Thoracic  Transection.  —  This  is  sometimes  desirable 
when  only  the  abdominal  and  pelvic  regions  are  to  be  examined  or 
preserved. 

The  primary  incision  should  be  transverse,  about  2  cm.  cephalad 
of  the  epigastrium.  The  mesosternum  may  be  divided  with  the 
nippers,  and  the  incision  then  carried  on  either  side  in  the  7th  inter- 
costal space.  The  thoracic  viscera  are  readily  separated  from  the 
diaphragm,  the  oesophagus,  aorta,  and  postcava  may  be  cut  1-2 
cm.  from  the  diaphragm,  and  the  dislocation  of  the  columna  verte- 
bralis  effected  between  the  seventh  and  eighth  thoracic  vertebrae. 

If  the  abdominal  viscera  are  to  be  preserved,  strong  alcohol 
should  be  injected  into  the  aorta,  and  into  the  abdomen  by  a  slit 
just  large  enough  to  admit  the  canula  ;  the  contents  of  the  stomach 
and  rectum  should  be,  if  possible,  washed  out  with  a  stream  of 
water,  aided  by  kneading ;  alcohol  should  then  be  injected  into 
both  cavities,  the  oesophagus  tied,  and  the  rectum  plugged  with 
cotton. 

The  abdominal  viscera  are  easily  displaced,  and  it  is  well  to 
let  the  caudal  region  of  the  body,  with  or  without  the  legs,  rest 
dorsicumbent  in  alcohol  for  several  days,  the  jar  being  securely 
closed,  and  placed  on  its  side  in  a  tray.  The  alcohol  should  be  re- 
newed at  the  end  of  a  week. 

§  243.    Removal  of  the  Tail. — In  some  cases  it  may  be  desirable  to  remove  the  tail. 

Girdle  it  with  the  arthrotome  near  the  base,  and  divide  it  with  the  nippers  and  bone 
scissors.     With  a  young  animal,  the  bone  scissors  may  be  used  without  the  nippers. 

With  a  freshly  killed  animal,  when  bleeding  is  undesirable,  a  twine  ligature  may  be 
tied  firmly  just  cephalad  of  the  point  of  intended  removal. 

If  only  the  muscles,  vessels,  and  nerves  are  to  be  studied,  the  daw  points  may  be 
removed  with  nippers. 


CHAPTER    III. 

PREPAKATIOlSr  OF  BONES— PERMANENT  PREPARATION  OP  SOFT  PARTS— THE  USE  OP 
ALCOHOL,  ETC. — JARS,  ETC. — FROZEN  SECTIONS  AND  DISSECTIONS — INFLATED 
PREPARATIONS — MEASUREMENT  OF  VOLUME  AND  CAPACITY. 

PREPARATION  OF  BONES. 

Special  Instruments  and  Material  : — Arseniate  of  Soda — Beans  or  Peas — Benzine 
—  Bone  Drill  —  Cement  —  Ether  —  Glycerin  —  Labels  (§  162)  —  Liquid  Soap  —  Macerating 
Dislies  —  Nail  or  Tootli  Brushes — Salt  Solution  —  Syringe  —  Turpentine  Oil  —  Wicker 
sheimer's  Liquid. 

§  244.  There  are  four  principal  methods  of  preparing  bones  for 
scientific  purposes : — 

(1)  Cutting  and  scraping  the  soft  parts  from  alcoholic  specimens. 

(2)  Allowing  Ants  or  Dermestes  to  remove  the  soft  parts  of  fresh 
specimens. 

(3)  Maceration  (putrefactive)  in  water. 

(4)  Boiling  with  liquid  soap. 

Greneral  Directions. — A.  If  one  can  choose  his  specimen,  a 
young  adult  should  be  selected.  In  too  young  animals  the  epiphy- 
ses are  apt  to  separate  easily  from  the  diaphyses,  and  the  symphy- 
ses open  too  easily.  On  the  other  hand,  old  animals  sometimes 
have  exostoses^  or  abnormal  growths  on  their  bones,  and  the  sym- 
physes and  sutures  are  liable  to  be  entirely  obliterated. 

B.  If  possible,  have  at  hand  for  reference  a  perfect  skeleton  of 
the  part  to  be  prepared,  so  that  the  exact  position  of  delicate  bones 
and  processes  may  be  seen,  and  hence  not  be  lost  or  broken  through 
inadvertence. 

C.  Whatever  method  is  employed,  it  is  better  to  divide  the 
animal  into  several  parts  by  cutting  some  of  the  principal  arthra, 
as  the  humero-scapular,  the  femoro-innominate,  the  occipito-atlan- 
tal,  and  the  lumbo-thoracic. 

D.  Labeling. — The  whole  animal  should  bear  a  label  giving  the 
name,  date,  sex,  and,  if  possible,  the  age.     Each  separated  part 


104  AJVA  TOMICAL     TECHNO  LOGY. 

should  bear  a  label  giving  the  above  general  data,  and  also  the 
name  of  the  part.  This  is  imperatively  necessary  with  the  verte- 
brae, the  ribs,  and  the  phalanges ;  hence  each  must  be  carefully 
labeled  as  it  is  separated  from  the  rest  of  the  body. 

E.  If  the  methods  of  maceration  or  heating  with  liquid  soap  are 
employed,  parts  like  the  pelvis  and  scapulae,  and  limb  bones, 
exclusive  of  the  manus  and  pes,  which  cannot  be  mistaken,  may  be 
put  together  and  labeled  as  for  the  whole  animal.  Parts  that  might 
be  difficult  to  distinguish  should  be  kept  in  separate  dishes,  and 
each  properly  labeled.  The  vertebrae  might  be  divided  into  tlK^ 
four  sets— cervical,  thoracic,  lumbar,  and  sacral ;  each  set  should 
then  be  connected  by  attaching  a  Manilla  hemp  string  to  a  wire  and 
passing  it  through  the  neural  canal  and  tying  the  ends.  The  order 
of  the  bones  cannot  then  be  changed  as  they  separate  in  the  macer- 
ating process. 

The  caudal  vertebrae  that  have  no  neural  canal  must  be  num- 
bered or  put  in  separate  dishes  or  vials  and  properly  labeled. 

The  ribs  of  one  side  at  least  should  be  removed  one  by  one,  and 
tied  in  order  on  a  string,  or  put  into  separate  dishes. 

Never  put  bones  of  different  animals  in  the  same  dish,  unless  they  differ  so  greatly  in 
size  or  conformation  that  confusion  would  be  impossible. 

F.  The  Jiumerus^  femur ^  tibia^  and  radius  should  be  drilled  at 
or  near  their  ends,  so  that  the  oily  matter  in  the  medullary  canal 
may  be  removed.  The  tibia  and  radius  may  be  drilled  in  the  artic- 
ular surfaces,  care  being  taken  to  reach  the  center  of  the  thickness 
of  each  bone.  The  distal  end  of  the  femur  may  be  drilled,  but  the 
proximal  hole  should  be  made  on  the  ventral  side,  between  the  tro- 
chanter and  the  articular  head.  With  the  humerus,  the  proximal 
hole  may  be  made  in  the  articular  surface,  about  midway  between 
the  base  of  the  trochiter  and  the  trochin,  but  cephalad  of  the  slight 
extension  of  the  Canalis  hicipitalis .  The  distal  hole  may  be  drilled 
half  way  through  the  diaphysis,  from  a  point  on  the  cephalic  aspect, 
at  the  junction  of  the  third  and  fourth  quarters. 

After  the  holes  are  made,  the  medullary  matter  may  be  broken 
up  with  a  wire,  and  most  of  it  expelled  by  syringing,  first  witli 
warm  water  and  afterward  with  liquid  soap,  or  spirits  of  turpentine, 
or  ether.  The  syringing  should  be  repeated  at  the  close  of  what- 
ever process  is  adopted  for  removing  the  fiesh. 

With  most  larger  animals,  and  with  some  smaller  ones,  it  may 
be  desirable  to  drill  the  ulna  and  fibula  also. 


MACERATION   IN    WATER.  105 

§  245.   Removing   Soft    Parts   from   Alcoholic   Specimens. — 

Animals  that  have  been  preserved  in  alcohol  may  have  their  bones 
cleaned  by  simply  cutting  and  scraping  away  the  soft  parts.  It 
will  be  necessary  to  take  great  care,  however,  or  the  delicate  pro- 
cesses, especially  of  the  skull,  will  be  broken  in  getting  off  the 
tough  connective  tissue.  After  the  bones  are  cleaned  as  well  as 
I)Ossible,  simply  allow  them  to  dry,  or  finish  the  cleaning  as  directed 
hereafter  (§  249). 

§  246.  Allowing  Ants  or  Dermestes  to  remove  the  Soft 
Parts  of  Fresh  Specimens. — The  skin  and  most  of  the  flesh  should 
be  dissected  away,  and  the  partially  cleaned  bones  left  in  a  damp 
room.  Dermestes  will  find  them,  and  the  larvae  of  the  beetles  will 
remove  the  soft  parts. 

If  the  aid  of  ants  is  to  be  sought,  the  bones  prepared  as  just 
directed  should  be  sprinkled  with  sugar  or  smeared  with  molasses 
or  honey.  Then  they  should  be  placed  in  a  box  pierced  with  small 
holes.  The  box  should  be  put  by  an  ant's  nest,  and  some  sugar 
sprinkled  around  the  holes  leading  into  it.  The  ants  will  clean  the 
bones  more  satisfactorily  than  the  Dermestes.  It  usually  takes 
about  a  week  for  them  to  clean  a  cat' s  arm. 

§  247.  Maceration  in  Water. — Employ  stone-ware,  porcelain 
or  glass  dishes,  if  possible,  to  avoid  discoloration  of  the  bones.  The 
bones  are  freed  from  skin  and  most  of  the  soft  parts,  separated, 
placed  in  separate  dishes  as  directed  above,  and  covered  completely 
with  clean  soft  water.  The  dishes  should  then  be  placed  in  a  room 
where  the  temperature  does  not  fall  below  18-20  C.  If  the  room  is 
still  warmer,  the  maceration  will  proceed  all  the  more  rapidly. 
The  water  should  be  changed  on  the  third  day,  and  again  on  the 
tenth,  to  avoid  discoloration. 

It  requires  from  a  fortnight  to  two  months  for  complete  macera- 
tion. The  bones  of  very  large  animals  may  require  even  a  longer 
time. 

If  possible,  maceration  should  be  done  in  a  separate  building, 
and  during  warm  weather.  If  done  during  cold  weather,  the  fire 
should  not  be  allowed  to  go  out,  or  adipocere^  a  waxy  substance, 
may  form,  which  is  difficult  to  remove.  If  the  maceration  is  done 
in  a  room  or  closet,  there  should  be  a  special  ventilating  flue  (g  196). 
During  maceration  the  bones  should  be  occasionally  examined. 
When  the  soft  parts  separate  readily,  the  water  covering  them 
should  be  carefully  poured  off,  and  a  gentle  stream  of  fresh  water 


106  AJVA  TOMICA  L     TECHNOL  OGY. 

allowed  to  play  upon  them.  Use  a  nail  or  tooth  brush  to  remove 
the  flesh,  and  if  it  is  necessary  employ  the  scissors,  forceps,  and  a 
dull  but  smooth-edged  knife  to  clean  some  parts ;  the  nippers  aid 
in  tearing  off  ligaments  and  tendons.  After  all  the  soft  parts  are 
removed,  rinse  the  bones  well  with  clean  water,  and  place  them  on 
white  paper  in  a  dry  room.  Do  not  fail  to  accompany  each  bone 
by  its  proper  label  (§  244  D). 

The  vertebrae,  ribs,  etc.,  should  be  kept  on  a  string  after  cleaning,  or  when  dry  they 
may  be  numbered.  The  skeleton  of  each  animal  should  be  kept  in  a  separate  box  and 
properly  labeled. 

§  248.  Liquid  Soap  Process. — The  cleaning  is  done  in  this  pro- 
cess by  heating  the  bones  in  a  dilution  of  the  following  mixture : 
Rain  (or  distilled)  water,  2000  cc. ;  strong  ammonia,  150  cc. ;  nitrate 
of  potash  (saltpetre),  12  grams  ;  hard  soap,  75  grams. 

Prepare  the  bones  by  removing  the  skin  and.  most  of  the  soft 
parts,  as  directed  for  macerating  (§  247). 

Place  the  bone,  or — if  several  are  to  be  prepared  from  the  same 
animal — those  that  cannot  be  mistaken  for  one  another,  in  a  vessel 
containing  water,  4  parts,  and  liquid  soap,  1  part. 

Prepare  enough  of  this  mixture  to  completely  immerse  the  bones. 
Boil  in  this  forty  minutes ;  then  pour  off  the  liquid  and  add  a 
similar  amount  prepared  in  the  same  way.  Boil  again  for  half  an 
hour ;  and  usually  the  muscles  may  be  removed  by  the  hands,  a 
smooth  stick,  or  a  scalpel  handle. 

As  it  wo  aid  take  too  long  for  the  bones  to  cool  spontaneously  before  working  upon 
them,  they  maj^  be  placed  directly  in  cold  water. 

After  removing  all  the  muscles  that  come  off  readily,  replace  the 
bones  in  the  dish  and  continue  the  boiling  until  the  soft  parts  may 
be  readily  removed  with  a  nail  brush. 

When  removing  the  soft  parts,  it  is  necessary  to  be  careful  not 
to  lose  small  bones. 

After  all  the  soft  parts  are  removed,  it  is  usually  best  to  boil  the 
bones  for  half  an  hour  in  a  mixture  of  equal  parts  of  the  liquid  soap 
and  water  to  remove  the  last  remnants  of  grease. 

Finally  rinse  the  bones  well  with  clean  water  and  lay  them  upon 
white  paper  to  dry. 

This  is  by  far  the  best  method  of  preparing  bones  :  (1)  The 
liquid  soap  saponifies  the  fat  and  aids  in  softening  connective  tissue. 
(-2)  The  bones  come  out  white  and  free  from  grease.     (3)  It  requires 


PREPARATION    OF    SKULLS.  107 

]:>iit  a  very  short  time  to  prepare  a  skeleton  or  a  part  of  a  skeleton. 
(4)  It  is  especially  adapted  for  skulls,  as  the  teeth  are  much  less 
liable  to  fall  out,  and  the  gelatinized  dental  periosteum  serves  as  a 
cement.  (5)  There  is  no  danger  of  blood  poisoning  (septicaemia)  if 
fresh,  healthy  animals  are  used.  There  is  no  danger  in  any  case 
after  the  bones  have  been  well  boiled. 

§  249.  Bones  are  not  satisfactorily  cleaned  by  ants  or  Dermestes.     The  cleaning  may  be 
very  satisfactorily  completed,  however,  by  boiling  in  the  mixture  of  liquid  soap  (§  248). 
The  final  cleaning  of  alcoholic  specimens  is  best  done  in  the  same  way. 

§  250.  Preparation  of  Skulls — A.  By  Maceration. — Separate 
the  skull,  remove  the  skin,  the  eyes  and  the  tongue.  Then  separate 
the  mandible,  but  let  the  os  hyoides  remain.  With  a  tracer  or  a 
piece  of  wire,  inserted  through  the  Foramen  magnum  (Fig.  57), 
break  up  the  brain,  taking  care,  however,  not  to  injure  the  project- 
ing bony  tentorium  (Fig.  59).  After  the  brain  is  broken  up  it 
should  be  washed  out  with  a  syringe. 

Place  the  skull  and  mandible  in  the  macerating  dish  so  that  the 
teeth  shall  be  uppermost ;  then,  if  the  water  is  changed  carefully, 
the  teeth  are  less  aj)t  to  fall  out  and  be  lost. 

The  cleaning  should  be  done  as  described  above  (§  247),  except 
that  greater  care  is  usually  necessary. 

B.  By  the  Liquid  Soap  Process, — The  skull  should  be  prepared 
as  described  for  maceration,  except  that  the  mandible  need  not  be 
separated.     Proceed  as  directed  above  (§  248). 

Skulls  can  be  much  more  quickly  and  safely  prepared  by  the  liquid  soap  process  than 
by  any  other. 

§  251.  Cements  for  Bones  and  Teeth,— The  pelvis  and  man- 
dible often  separate  at  their  symphyses,  and  the  teeth  may  become 
loose  and  be  in  danger  of  falling  out.  This  latter  is  especially 
liable  to  occur  with  macerated  skulls.  To  unite  bones>  one  should 
use : — 

A.  Liquid  gelatin  (see  Formula,  §  1446).  Attach  the  bones 
firmly  by  a  rubber  band  or  string  while  the  gelatin  is  drying.  The 
method  is  the  same  as  for  gluing  wood. 

Teeth  may  be  fastened  in  their  sockets  by  the  same  substance, 
only  it  is  unnecessary  to  bind  them  in  while  the  gelatin  is  drying. 
The  skull  should  rest  on  its  dorsal  side,  and  the  mandible  on  its 
ventral  side,  so  that  the  teeth  may  remain  in  place  during  the 
drying. 


108  ANATOMICAL    TECHNOLOGY. 

B.  An  excellent  cement,  for  teeth  especially,  is  the  following  : — 
Silicate  of  soda  or  potassa  (liquid  glass)  mixed  to  a  paste  with 
powdered  chalk.     This  hardens  quickly,  therefore  it  must  be  used 
soon  after  it  is  prepared.     Neither  this  nor  the  gelatin  will  resist 
water. 

As  soon  as  a  macerated  skull  is  rinsed,  the  teeth  that  are  loose 
should  be  taken  out  one  at  a  time,  the  socket  partly  filled  with  one  of 
the  cements  and  the  tooth  replanted.  In  this  way  the  teeth  may  be 
kept  in  their  proper  places,  and  as  the  skull  dries  the  teeth  will  be 
firmly  fixed.  Although  the  teeth  of  skulls  prepared  by  the  liquid 
soap  process  may  be  loose  before  the  skull  is  dry,  the  gelatinized 
dental  periosteum  will  usually  fasten  them  very  firmly  as  the  skull 
dries.  If  any  of  the  teeth  come  out  they  should  be  replanted  as 
directed  above. 

Need  of  Accuracy, — So  far  as  concerns  tlie  general  aspect  of  the  skull,  tlie  incisors 
may  be  interclianged,  and  missing  teeth  may  be  replaced  by  teeth  from  other  skulls.  It 
is  to  be  feared  that  such  substitutions  are  sometimes  made  with  skulls  prepared  for  sale. 
Unless  the  changes  are  carefully  specified,  such  skulls  have  no  real  scientific  value  as 
regards  the  teeth. 

When  two  or  more  of  the  teeth  drop  out  at  the  same  time,  unless  direct  observation  or 
comparison  with  a  fresh  or  alcoholic  specimen  warrants  absolute  certainty,  it  is  better  to 
keep  those  teeth  in  a  box  separate  from  the  rest. 

§  252.  Preparation  of  Natural  Skeletons. — By  a  natural 
skeleton  is  meant  one  in  which  the  bones  are  held  together  by  their 
natural  ligaments.  Such  a  skeleton  may  be  prepared  according  to 
either  of  the  processes  described  above.  One  must,  however,  watch 
that  the  ants  may  remove  only  the  muscles,  or  that,  in  the  process 
of  maceration,  only  the  muscles  decay.  In  all  the  processes,  the 
muscles  are  softened  or  removed  first.  If  the  liquid  soap  process  is 
employed,  proceed  as  follows :  Boil  the  bones  in  the  mixture  as 
directed  (§  248)  until  the  muscles  may  be  removed  without  much 
trouble.  It  will  be  found  necessary,  however,  to  allow  the  boiling 
to  proceed  only  to  the  point  where  the  muscles  will  separate  from] 
the  bones  by  using  the  hands,  a  smooth  stick  like  a  scalpel  handle,! 
or  a  dull  knife  blade.  The  ligaments  will  be  found  considerably 
swollen  and  somewhat  softened.  The  softened  ectal  surface  maybe 
cautiously  scraped  off ;  then  the  preparation  should  be  soaked  for^ 
3-6  hours  in  a  saturated  solution  of  arseniate  of  soda  (about  25  pei 
cent.),  to  poison  the  ligaments  and  protect  them  from  Dermestes.] 
Then  the  part  should  be  arranged  as  nearly  as  possible  in  a  natuK 


DISARTICULATING     SKULLS.  109 

position  and  fastened  with  pins  or  strings  and  allowed  to  dry.  The 
swollen  ligaments  will  shrink  very  greatly,  so  that  what  might  have 
seemed  a  very  imperfect  preparation  when  moist  will  be  excellent 
when  dry.  When  the  specimen  is  dry,  rough  projections  of  liga- 
ment may  be  removed  v/ith  a  sharp  knife. 

Flexible  Natural  Skeletons. — If  it  is  desired  to  have  the  lig- 
aments flexible,  the  preparation  may  be  soaked  after  it  is  partly 
dry  for  from  16  to  12  hours  in  either  Wickerscheimer' s  fluid  (§  299), 
or  a  mixture  of  a  saturated  aqueous  solution  of  arseniate  of  soda,  4 
parts,  and  glycerine  1  part. 

§  253.   Preparation  of   the   Bones  of  Young  Animals. — The 

liquid  soap  process  is  to  be  preferred.  But  during  the  boiling  the 
bones  must  be  carefully  watched,  and  the  boiling  should  be  carried 
little  farther  than  for  making  natural  skeletons.  The  epiphyses 
must  not  be  allowed  to  separate  from  the  diaphyses. 

The  skulls  of  new  born  kittens  may  be  nicely  prepared  in  this 
way,  and  the  sutures  show  with  great  distinctness. 

§  254.  Disarticulating  Skulls. — Choose  a  young  or  barely 
mature  animal  for  this  preparation,  since  the  cranial  sutures  are 
liable  to  be  obliterated  in  adults. 

Prepare  the  skull  by  the  liquid  soap  process  (§  248).  Continue 
the  final  boiling  for  half  an  hour  longer  than  for  a  skull  that  is 
not  to  be  disarticulated.  While  still  moist,  the  bones  may  be 
separated  by  steady  traction.  This  may  be  done  with  the  greatest 
ease  if  half  grown  animals  are  used. 

Skulls  that  have  become  dry  may  be  boiled  for  half  an  hour  in 
the  liquid  soap  to  soften  the  gelatinized  connective  tissue  binding 
them  together. 

Macerated  young  skulls  may  be  disarticulated  by  carefully 
pulling  and  prying  the  bones  apart. 

An  excellent  plan  is  to  fully  disarticulate  one  side  of  a  skull,  and  to  leave  the  other 
with  the  bones  in  situ. 

Disarticulation  of  Large  Slculls. — If  a  large  skull  is  prepared 
by  the  liquid  soap  process  it  should  be  thoroughly  softened  by 
soaking  in  water  two  or  three  days  or  by  boiling  an  hour.  Then 
fill  the  cranial  cavity  with  dry  beans  or  peas,  force  a  cork  tightly 
into  the  foramen  magnum  (Fig.  57)  and  place  the  skull  in  water. 
-The  swelling  of  the  peas  will  forco  the  bones  apart.     Macerated 


110  ANATOMICAL    TECHNOLOGY, 

skulls  should  be  treated  as  just  described,  but  tbey  need  not  be 
boiled. 

§  255.  Bleaching  Bones.— In  order  that  bones  should  be  white 
and  clean,  it  is  necessary  that  they  be  relieved  of  all  their  grease 
and  blood.  Neither  of  these  ends  is  accomplished  when  the  flesh  is 
removed  by  insects — ants  or  Dermestes.  Both  are  fairly  well  accom- 
plished by  proper  maceration ;  and  both  still  better  by  the  liquid 
soap  process. 

The  old  method,  and  the  one  still  largely  employed  in  whitening 
bones,  is  to  place  them  where  they  are  constantly  exposed  to  the 
action  of  the  sun,  rain  and  dew.  The  following  methods  are,  how- 
ever, more  speedy  and  satisfactory : — 

The  blood  is  usually  got  rid  of  in  the  process  of  boiling  or  macer- 
ation. If,  however,  one  wishes  to  prepare  bones  in  the  best  possible 
manner,  the  entire  vascular  system  may  be  washed  out  with  normal 
salt  solution.  To  do  this,  insert  a  canula  into  the  arch  of  the 
aorta  (Fig.  101) ;  open  the  prsecava  (Fig.  101)  just  peripherad  of  the 
heart,  and  then,  with  a  syringe,  inject  salt  solution  into  the  aorta 
until  it  runs  uncolored  from  the  prsecava.     See  also  p.  111. 

§  256.  Freeing  Bones  from  Grease. — There  are  four  ways  of 
removing  grease  from  bones  : — 

A.  By  suspending  them  in  spirits  of  turpentine— Oleum  terebin- 
thinse  rectificatum — (ordinary  commercial  oil  of  turpentine  will  do), 
for  three  or  four  weeks.  An  indefinite  soaking  in  turpentine  will 
do  no  harm  if  the  bones  are  suspended,  and  more  than  four  weeks 
may  be  necessary  for  large  bones. 

The  turpentine  should  be  very  fluid. 

The  bones  must  be  suspended  so  that  the  thick,  oily  substance 
that  settles  to  the  bottom  of  the  vessel  cannot  touch  them. 

After  the  bones  have  soaked  for  a  suflacient  time  in  the  turpen- 
tine, they  should  be  exposed  to  sunlight  but  not  to  rain. 

B.  Suspension  in  henzine  (common  commercial  benzine  will  do 
very  well).     The  bones  should  be  treated  as  directed  for  turpentine. 

0.  Soaking  the  bones  in  sulphuric  ether.  The  bones  need  not 
be  suspended,  simply  placing  them  in  the  vessel  with  the  ether  will 
be  sufficient.  The  ether  dissolves  the  grease  very  quickly,  so  that 
small  bones  like  those  of  the  cat  are  entirely  freed  from  grease  in  a 
fortnight  or  even  a  less  time.  The  bones  should  be  exposed  to  light 
as  directed  above. 


PRESERVATION    OF    SOFT    PARTS.  Ill 

Ether  is  expensive,  but  tlie  use  of  it  for  removing  grease  from  bones  does  not  injure 
it  for  anaestlietizing  animals.     It  is  said  to  render  bones  brittle. 

As  turpentine,  benzine,  and  ether  are  very  volatile,  they  must  be  kept  in  tio-ht  vessels. 
The  preserving  jars  (Fig.  32)  answer  very  well  for  the  bones  and  either  of  these  agents. 

Either  of  the  three  preceding  methods  may  be  employed  for  removing  grease  from 
natural  skeletons.  The  following  method  is  also  good  for  that  purpose,  but  not  quite  so 
safe,  as  there  is  soma  danger  of  loosening  the  ligaments. 

D.  Soaking  the  bones  in  liquid  soap.  Place  the  bones  in  a  dish 
of  liquid  soap  (§  248)  and  let  them  remain  for  three  or  four  days,  in 
some  cases  longer,  then  wash  them  very  thoroughly  with  clean 
water.  Dry  them  and  expose  them  to  the  sun  (§  256).  It  is  not 
usually  necessary  to  treat  bones  that  have  been  prepared  by  the 
liquid  soap  process,  but  bones  that  have  been  macerated  or  pre- 
pared by  insects  may  be  relieved  of  their  grease  in  this  way.  It 
may  be  desirable  to  mix  the  liquid  soap  with  an  equal  amount  of 
water  and  boil  for  half  an  hour  or  more. 

Peroxide  of  hydrogen  has  been  found  the  safest  and  most  rapid 
agent  for  bleaching  bones.  A  so-called  12  vol.  per  cent,  solution  is 
mixed  with  an  equal  volume  of  water,  and  rendered  neutral  or 
slightly  alkaline  by  the  addition  of  ammonia  or  carbonate  of  soda. 
The  thoroughly  dried  and  degreased  bones  are  placed  in  this  in  a 
closed  vessel  like  a  preserving  jar  (§  313).  The  bleaching  is  usually 
sufficient  in  two  to  fiYe  days. 

It  is  necessary  to  keep  the  peroxide  tightly  corked  and  in  a  cool 
place  to  prevent  deterioration. 

THE  PRESERVATION  OF  SOFT  PARTS. 

§  257.  Practically,  a  bone  once  properly  cleaned  is  imperisha- 
ble, and  needs  only  to  be  protected  from  dust  or  injury.  But  all 
the  soft  parts  of  the  body  are  more  or  less  prone  to  decompose  at 
common  temperatures  and  under  ordinary  conditions  ;  even  when 
treated  with  preservatives,  they  are  liable  to  deteriorate  unless  con- 
stantly cared  for. 

Many  agents  have  been  employed  for  the  delay  or  prevention  of  decomposition,  and 
for  the  permanent  preparation  of  soft  parts.  Personal  experience  enables  us  to  speak  con- 
fidently of  only  three — cold,  arserdate  of  soda,  and  alcoJiol. 

A  few  other  agents — brine,  methyl  alcohol,  chloral  and  Wicker sheimer' 8  liquid — will  be 
briefly  mentioned. 

§  258.  Cold. — Decomposition  is  prevented  by  a  temperature  of  0  C.  (32  F.),  and  is 
more  or  less  retarded  at  temperatures  between  0  and  10. 

Cold  may  be  employed  alone  for  freezing  specimens  so  as  to  keep  indefinitely ;  more 


112  ANATOMICAL    TECHNOLOGY. 

often,  decomposition  is  simply  retarded  by  it,  wbile  the  specimen  is  temporarily  protected 
by  arseniate  of  soda  or  permanently  preserved  by  means  of  alcohol. 

Frozen  sections  and  dissections  will  be  discussed  later  in  this  chapter. 

§  259.  Arseniate  of  Soda — Sodium  Arsenias.—A  saturated  solution  of  this  poisonous 
salt  may  be  used  for  the  iujection  of  specimens  which  are  to  be  dissected  fresh,  or  for  the 
poisoning  of  inflated  preparations. 

Water  dissolves  about  one  fourth  of  its  weight  of  arseniate  ;  hence  the  saturated  solu- 
tion is  20-35  per  cent.  It  should  not  be  allowed  to  remain  upon  the  dissector's  skin 
longer  than  necessary. 

Here  and  elsewhere,  when  a  solution  or  mixture  is  mentioned,  the  menstruum  is  toater 
imless  the  contrary  is  stated. 

ALCOHOL. 

§  260.  Alcohol  is  almost  essential  in  practical  anatomy;  its 
qualities  are  active,  and  its  management  requires  constant  care. 

General  Description.— The  alcohol  commonly  employed  for 
Natural  History  purposes  is,  strictly  speaking,  ethylic  alcohol^  and 
a  member  of  a  group  including  several  others,  the  amylic^  hutylic, 
propyUc,  methylic,  etc.  The  last  named  variety  will  be  mentioned 
again  in  §  298. 

Ethyl  alcohol  is  colorless,  volatile,  and  inflammable ;  it  has  a 
vinous  odor  and  pungent  taste  ;  it  coagulates  albuminous  sub- 
stances and  extracts  more  or  less  water  from  organisms  immersed 
in  it.     Its  composition  is  CgHeO.     Its  specific  gravity  is  796. 

Absolute  Alcohol. — The  foregoing  statements  as  to  composition  and  specific  gravity 
really  apply  only  to  pure  or  absolute  alcohol,  that  is,  alcohol  which  has  been  freed  from 
water  and  all  impurities.  This,  however,  is  quite  expensive  (about  $8.00  per  gal.),  and  is 
required  only  for  some  histological  purposes. 

Ordinary  or  Commercial  Alcohol  contains  from  5-60  per  cent,  of  water.  Most  of  these 
mixtures  are  commonly  called  alcohols,  but  some  of  the  grades  have  also  special  names,  as 
indicated  upon  the  following  Table  : — 

§  261.  Table  of  Specific  Gravities  of  different*  Percentages  of  Alcohols 

AT  151°  C,  60°  F. 


100,  .796,  Absolute  alcohol. 
95,  .809,  [Commercial  alcohol.] 
92,  .817,  Alcohol  fortius,  U.  S. 
89,  .825,  Lightest  spirit  obtained  by  ordi- 
nary distillation. 
85,  .835,  Alcohol,  U.  S,,  spiritus  recti fica- 
tus,  rectified  spirit. 
United  States  Dispensatory,  13th  edition,  1880.     See  also  Watts,  A,  and  Baley,  A 


84,  .838,  Spiritus  rectificatus,  Br. 

75,  .860. 

60,  .896. 

50,  .917,  [Strong  liquors,  whisky,  etc.] 

49,  .920,  Spiritus  tenuior,  proof  spirit,  Br. 

39,  .941,  Alcohol  dilutum,  U.  S. 


Alcohol  as  received  from  the  warehouse  usually  contains  about  95  per  cent,  of  absolute 
alcohol;  but  that  which  has  been  kept  for  some  time,  especially  if  frequently  exposed  to 
the  air,  is  apt  to  range  from  90-94  per  cent.,  on  account  of  evaporation  and  the  absorption 
of  water  from  the  air. 


ALCVSOL,  113 

The  strong  liquors — brandy,  gin,  rum,  and  wMsky — contain  from  45-55  per  cent,  of 
absolute  alcoliol.  A  mixture  containing  less  than  20  per  cent,  is  not  directly  useful  iu 
zoology. 

§  262,  The  Leading  Characteristics  of  Alcohol. — Ethyl  alcohol 
has  twelve  prominent  characteristics,  of  which  one  half  are  desirable 
and  the  other  half  undesirable  from  the  zoological  point  of  view : — 

It  is  simple,  cleanly,  colorless,  siud  fragrant,  generally  obtain- 
able, and — as  a  preservative — absolutely  efficient. 

On  the  other  hand,  it  is  costly,  volatile,  inflammable,  and  decol- 
orant, quick  to  absorb  water  from  the  air,  and — under  certain  gou- 
dition^— -corrosive  of  some  metals. 

§  263.  Alcohol  should  be  used  with  discretion,  always  closely 
covered,  secured  from  lire,  and  kept  in  vessels  of  glass,  hard  wood, 
copper,  zinc,  or  galvanized  iron, 

§  264  The  Cost  of  Alcohol. — This,  of  course,  is  an  extrinsic  feature,  and  varies  much 
in  different  parts  of  the  world.  In  most  civilized  countries,  to  the  actual  cost  of  its  pro- 
duction is  added  a  heavy  government  tax,  and  the  retail  price  in  the  United  States  is  about 
$2.50  per  gallon,  or  50-75  cents  per  liter. 

This  high  price  of  the  liquid  best  adapted  for  the  preservation  of  specimens  has  directly 
and  seriously  retarded  all  anatomical  and  zoological  progress.  At  various  times  between 
1863  and  1879,  at  the  request  of  the  late  Prof.  Louis  Agassiz  and  others,  with  the  co-opera- 
tion of  the  Hon.  S.  Hooper  and  others.  Congress  wisely  made  provisions  (U.  S.  Revised 
Statutes,  §3297),  by  which,  under  very  stringent  conditions  and  with  heavy  pecuniary  lia- 
bilities in  case  of  the  slightest  misapplication,  museums  and  ether  educational  institutions 
*'may  withdraw  alcohol  from  bonded  warehouses  without  payment  of  tax,  for  the  sole  and 
exclusive  purposes  of  use  in  the  chemical  laboratory,  or  for  the  preservation  of  Natural 
History  specimens  belonging  to  such  institutions,"  The  cost  of  alcohol  so  obtained  is 
about  one  sixth  of  the  retail  price.     See  Appendix. 

The  instructions  for  so  obtaining  alcohol  for  scientific  purposes  are  printed  in  No.  7, 
Scries  7  of  the  U.  S.  Revenue  Dapartment,  p.  43,  which  may  be  had  from  the  Collectors. 

Since  no  variation  from  the  prescribed  forms  is  permitted,  great  care  must  bo  taken  lu 
making  out  the  application  and  band  ;  those  who  obtain  alcohol  annually  will  save  trouble 
and  sometimes  serious  delay  by  having  the  forms  printed. 

After  making  out  the  form  of  the  application  and  bond,  and  inserting  the  names  of  the 
two  sureties,  some  proprietor  of  a  bonded  warehouse  should  be  asked  to  set  aside  the  num- 
ber of  barrels  (40-45  gals,  each)  of  alcoliol  desired,  and  to  send  a  memorandum  of  the 
marks  and  other  items  required  in  the  papers.  If  the  forms  are  printed,  a  copy  of  the 
application  form  may  be  sent,  so  that  the  various  numbers  may  be  filled  in,  together  with 
the  number  of  the  collection  district  in  which  the  warehouse  is  located.  This  copy  should 
be  retained  for  reference  in  making  the  assurance  afterward  required. 

The  papers  should  then  be  promptly  filled  out,  care  being  taken  that  the  signatures  of 
the  sureties  coincide  as  to  initials  and  abbreviations  with  the  names  as  entered  iu  the  body 
of  the  bond.  The  papers  are  to  be  transmitted  to  the  Commissioner  of  Internal  Revenue 
through  the  Collector  of  the  district  in  which  the  institution  is  located.  If  the  papers 
have  been  properly  made  out,  the  permit  may  be  received  within  ten  days. 

No  form  is  prescribed  for  the  assurance  of  the  Revenue  Department  that  the  alcohol 
8 


114  ANATOMICAL    TECHNOLOGY. 

lias  been  used  for  the  prescribed  purposes  within  the  specified  time.  It  is  necessarjMo 
make  oath  before  the  proper  officer  to  this  effect,  giving  the  marks  of  the  alcohol  and  the 
date  of  the  original  application.  This  affidavit  is  to  be  transmitted  to  the  Commissioner 
of  Internal  iievenue  ttirough  the  Collector  of  the  district  in  which  the  institution  is  located. 

Since  it  is  not  always  easy  to  ascertain  the  location  of  warehouses,  it  may  be  proper  to 
inetitioD  that  alcohol  may  be  obtained  promptly  under  the  foregoing  conditions  irom 
Messrs.  E.  N.  Cook  &  Co.,  of  Buffalo,  N.  Y.,  who  also  furnish  blanks. 

I  285.  Inflammability. — At  ordinary  temperatures — 15-20'  C. — a  mixture  of  alcohol 
and  water  containing  30  per  cent,  or  less  of  absolute  alcohol  cannot  be  ignited,  and 
promptly  extinguishes  a  lighted  ixlatch  dipped  into  it;  85  per  cent,  ignites  with  difficulty, 
and  the  flame  is  extinguished  by  the  lightest  current  of  air ;  40  and  45  per  cent,  ignite 
more  readily,  but  burn  gently  and  slowly.  Even  65  per  cent,  does  not  burn  fiercely,  and 
the  flame  is  easily  extinguished.  Specimens  saturated  with  alcohol  are  more  combustible 
in  proportion  to  the  sti-ength  of  the  alcohol. 

Other  Inflammable  Substances.  SiiW  more  volatile  and  inflammable  are  the  ether,  ben- 
zine and  spirits  of  turpentine  which  are  used  in  anatomical  work. 

§  266.  Precautions  against  Fire. — Alcohol,  benzine,  ether,  and  spirits  of  turpentine  in 
bulk  should  be  stored  in  a  fire-proof  vault,  or  in  some  small  building  apart  from  valuable 
collections  and  apparatus.  In  the  laboratory  there  should  be  not  more  than  20  liters  of  95 
per  cent,  alcohol,  and  of  the  other  liquids  only  enough  for  current  uses.  All  of  tliem 
should  be  kept  in  glass  or  copper  vessels,  well  stoppered  and  at  a  safe  distance  from  all 
lights  and  heating  apparatus.  They  should  never  be  opened  within  one  meter  of  a  light, 
and  if  there  is  a  current  of  air  toward  the  light,  the  distance  should  be  at  least  doubled. 

When  removed  from  alcohol  for  examination  or  dissection,  specimens  should  be  washed 
off  with  water,  and  kept  wet  with  the  15  per  cent,  glycerin  solution,  as  directed  elsewhere. 
This  precaution  is  the  more  essential  when  anatomical  work  is  done  by  artificial  light. 

Cotton  and  cloths  which  have  been  saturated  with  alcohol  or  other  inflammable  liquids 
should  be  dried  on  trays  in  the  sun  or  wind  rather  than  near  a  fire.  Common  cotton 
should  be  thrown  away  after  use  in  alcohol,  but  absorbent  cotton  may  be  saved  if  thor- 
oughly dried. 

Safety  matches  are  to  be  preferred.  All  matches  should  be  kept  in  metal  or  glass 
boxes.  After  using,  matches  should  be  put  into  a  glass  or  metal  receptacle,  and  never 
thrown  on  the  floor. 

Smoking  in  a  laboratory  where  alcohol  is  used  should  be  absolutely  forbidden. 

§  267.  Determination  of  the  Percentage  of  Alcohol  in  an 
Alcoholic  Liquid. — This  may  be  done  by  means  of  either  a  Speci- 
fic Gravity  Hydrometer  or  an  Alcoometer  (alcoholometer).  For 
zoological  purposes  the  latter  instrument  is  more  convenient  and 
sufficiently  exact. 

§  268.  Alcoometer  (alcoholometer). — This  is  a  form  of  hydrome- 
ter or  areometer  especially  adapted  to  determining  the  volume  or 
weight  percentage  of  alcohol  in  a  mixture  of  alcohol  and  water. 

It  is  a  graduated  tube,  loaded  so  as  to  rest  vertically  in  any 
liquid  capable  of  floating  it.  The  alcoometer  of  Tralles  is  com- 
monly employed  in  this  country  ;  it  indicates  the  volume  per  cent. 

In  pure  water  the  instrument  sinks  only  to  zero^  the  lower  end 


CHANGIXG     THE    PERCENTAGE    OF    ALCOHOL,  115 

of  the  scale.  In  absolute  alcohol  it  sinks  to  100,  the  upper  end. 
Mixtures  of  the  two  liquids  permit  it  to  sink  to  various  depths,  and 
the  number  corresponding  with  the  surface  of  the  liquid  indicates 
the  percentage  of  alcohol  by  volume. 

A.  Alcohol  that  has  been  used  for  the  preservation  of  specimens  usually  holds  in  solu- 
tion or  suspension  substances  of  greater  specific  gravity  than  alcohol  or  even  water.  Their 
presence  increases  the  specific  gravity  of  the  liquid,  and  causes  the  per  cent,  of  alcohol  to 
appaar  less  than  it  really  is.  Old  alcohol  should  therefore  be  cleared  (§  294),  if  necessary, 
before  testing  w^ith  the  alcoometer ;  but  filtration  will  not,  of  course,  remove  materials 
which  are  in  real  solution. 

B.  As  stated  by  Giinther  (§  A,  697),  the  British  hydrometer  is  so  arranged  that  the 
zero  corresponds  with  proof  spirit,  about  49  per  cent.  The  other  grades  are  designated  as 
so  many  degrees  above  or  below  proof,  and  two  degrees  equal  but  one  per  cent.  For 
example,  our  95  per  cent,  alcohol  would  be  92  above  proof,  while  20  below  proof  would 
indicate  the  presence  of  39  per  cent,  of  absolute  alcohol. 

§  269.  Hydrometer  Jar. — This  is  a  tall  and  narrow  glass  jar, 
mounted  on  a  foot.  The  alcohol  to  be  tested  is  poured  into  it,  and 
the  scale  may  be  read  through  the  glass. 

Any  glass  jar  of  sufficient  height  {e.  g.  the  3  x  10  in.  jar  of  Whitall,  Tatum  &  Co.,  A), 
answer  in  using  the  alcoometer,  but  the  narrowness  of  the  proper  hydrometer  jar 
requires  a  less  quantity  of  the  liquid,  and  the  scale  is  read  more  easily.  A  cylindrical 
graduate  on  a  foot,  and  holding  about  500  cc,  makes  an  excellent  hydrometer  jar,  but  is 
I  more  expensive.  Finally,  a  cheap  one  may  be  made  by  corking  one  end  of  a  tail  lamp 
|||j«nney  or  piece  of  large  glass  tubing,  and  fixing  it  into  a  hole  in  a  wooden  disk. 
^^^BtJnless  care  is  sure  to  be  observed  in  introducing  the  alcoometer,  a  piece  of  soft  sponge 
^^^■ome  cotton  should  be  pushed  to  the  bottom  of  the  jar. 

i^^§  270.    Changing  the  Percentage   of  Absolute   Alcohol  in  a 

Mixture. — This  may  be  done  by  mixing  two  grades  of  alcohol,  or 

by  adding  water  to  one  of  them.    The  due  proportions  may  be 

'  ascertained  either  by  experiment  or  by  the  arithmetical  method 

I  known  as  alligation  alternate. 

I  §  271.  Bute  of  Alligation  Alternate. — Find  the  difference  be- 
I  tween  the  required  per  cent,  and  the  per  cent,  of  each  of  the  liquids 
I  to  be  combined.  AVrite  the  reciprocal  of  each  of  these  different 
I  numbers,  and  reduce  the  fractions  to  a  common  denominator.  The 
I  numerators  will  then  represent  the  proportionate  volumes  of  the 
\  two  liquids. 

Examples. — Water  and  95  per  cent,  alcohol  are  to  be  so  combined  that  the  per  cent,  of 
the  mixture  will  be  50  ;  95  —  50  =  45  ;  50  —  CO  (the  water)  =  50.  The  reciprocals  of  the 
TWO  numbers  are  ^j^  and  ^^-^  ;  reduced  to  a  common  denominator,  these  fractions  become 
i.-!i,  and  jVfj^  respectively;  hence  9  volumes  of  water  are  to  be  added  to  10  volumes  of  alco- 
hol.    On  the  alcoometer  the  per  cent,  of  the  mixture  will  be  indicated  as  about  55. 

Again,  two  grades  of  alcohol,  respectively  75  and  30  per  cent.,  are  to  be  combined  so 


116 


A  NA  TOMICA  L     TECHNOL  OGT, 


that  the  per  cent,  of  the  mixture  shall  be  50  ;  50  —  30  =  20  ;  75  —  50  =  35.  The  recipro- 
cals are  ^^  and  Jg  ;  reduced  to  a  common  denominator,  these  fractions  become  y^^  '^I'd 
iBc^)  consequently  5  volumes  of  30  per  cent,  alcohol  are  to  be  added  to  4  volumes  of  75 
per  cent,  in  order  that  the  per  cent,  of  the  mixture  may  be  50.  Upon  the  alcoometer  the 
per  cent,  is  about  52, 

Owing  to  the  unequal  specific  gravities  of  alcohol  and  water,  and  the  contraction  which 
occurs  when  they  are  mixed,  the  results  obtained  by  this  method  are  only  approximate,  as 
indicated  by  the  alcoometer.     They  are,  however,  sufficiently  close  for  most  purposes. 

When  liquids  of  different  specific  gravities  are  mixed,  they  should  be  thoroughly 
shaken  together  before  testing  with  the  alcoometer, 

§  272.  Determining  the  Ratio  hy  Experiment.— Wh^i^i  a  given 
volume  of  alcohol  is  to  be  made  either  stronger  or  weaker,  the  end 
may  be  reached  experimentally  in  either  of  two  ways :  The  entire 
volume  of  the  alcohol  to  be  changed  may  be  placed  in  a  jar,  and 
the  modifying  liquid —whether  water  or  weaker  or  stronger  alcohol — 
may  then  be  introduced  gradually  until  the  desired  per  cent,  is 
attained ;  or  a  given  volume  of  the  alcohol  to  be  changed  may  be 
placed  in  the  hydrometer  jar,  and  given  volumes  of  the  other  liquid 
induced.  Having  ascertained  the  ratios,  larger  volumes  may  be 
mixed  accordingly. 

In  both  these  cases,  the  two  liquids  must  be  thorougJily  shalien 
or  stirred  together  before  testing. 

§  273.  Reduction  of  95  per  cent.  Alcohol  hy  the  Addition  of 
Water. — Since  this  is  the  change  most  frequently  made,  we  have 
ascertained  by  the  alcoometer  the  results  of  the  mixture  of  water 
and  alcohol  in  various  simple  ratios.  These  ratios  are  given  in  the 
following  Table  : — 


VOLUMES. 

VOLUMES. 

REQUIRED  PER- 

REQUIRED PER- 
CENTAGE. 

CENTAGE. 

Alcohol, 

Water. 

Alcohol. 

Water. 

84 

6 

55 

1.1 

1 

82 

5 

48 

1 

78 

4 

45 

1.35 

75 

3 

42 

1.5 

67 

2 

35 

2 

63 

1.5 

30 

3 

60 

1,25 

22 

4 

59 

1.2 

§  274.  Water  to  he  Mixed  with  Alcohol. — If  the  mixture  is  for  the  hardening  or  storage 
of  specimens,  any  clean  water  will  answer.  But  if  for  the  exhibition  of  finished  prepara- 
tions, the  water  should  be  either  distilled,  or  rain  water  filtered ;  otherwise  the  mixture  is  i 
liable  to  be  clouded. 


THE    ECONOMICS    OF   ALCOHOL.  117 

§  275.  The  Economics  of  Alcohol. — In  the  economical  employ- 
irient  of  alcohol,  four  matters  are  to  be  considered  :  (1)  The  use  of 
different  grades  for  appropriate  purposes ;  (2)  The  prevention  of 
evaporation;  (3)  The  avoidance  of  leakage;  (4)  The  improvement 
of  "old"  (deteriorated)  alcohol. 

§  276,  Tfie  Use  of  Appropriate  Grades. — Upon  zoological  specimens  alcohol  is  em- 
})loyed  for  three  distinct  purposes  :  preparation ;  storage ;  exhibition,  DiflFerent  degrees 
of  clearness  and  strength  are  needed,  for  these  different  purposes,  and  the  safety  of  speci- 
mens, economy,  and  the  appearance  of  collections  depend  upon  the  use  of  each  grade  for 
its  appropriate  purpose.  For  example,  the  commercial  (95  percent.)  alcohol  is  just  strong 
enough  for  some  purposes,  much  too  strong  for  others,  and  needlessly  clear  and  pure  for 
others. 

The  following  remarks  apply  to  all  vertebrates,  and  the  more  general  ones  to  most 
invertebrates  also.  Among  the  invertebrates  the  jelly  fishes  and  some  other  soft  forms 
cannot  be  satisfactorily  preserved  by  means  of  alcohol,  and  most  of  the  rest  should  be 
treated  like  the  brains  and  embryos  of  vertebrates. 

§  277.  Strong  alcohol  coagulates  the  tissues  so  as  to  form  a  firm 
ectal  layer,  through  which  it  afterward  passes  with  difficulty. 
With  a  small  specimen,  the  only  objection  may  be  the  corrugation 
and  distortion  of  the  specimen.  But  witli  a  large  and  fleshy  one, 
the  outside  may  harden  while  the  interior  is  actually  decomposing. 

There  is  no  difficulty  in  preserving  the  skeletal  muscles  and 
the  limbs,  but  the  brain  and  abdominal  viscera,  especially  the  liver, 
are  not  only  more  prone  to  decomposition  than  the  muscles,  but 
naturally  excluded  by  them  from  the  alcohol.  Unless,  therefore, 
definite  measures  are  taken  prior  to  immersion  (§  286),  some  of  the 
viscera  will  surely  fail  to  be  preserved.  These  measures  will  vary 
according  to  the  size  of  the  specimen  and  the  use  to  be  made  of 
it,  and,  under  some  circumstances,  the  opportunity  for  using  the 
required  instruments. 

§  278.  The  four  accessory  measures  are  named  in  the  order  of 
their  simplicity  :  (1)  Freely  opening  the  abdomen ;  (2)  Injecting 
alcohol  into  the  thorax  and  abdomen ;  (3)  Injection  of  alcohol  into 
the  large  hollow  viscera  ;  (4)  Injection  of  alcohol  into  the  arteries. 

g  279.  As  a  preliminary  to  any  of  them,  the  animal  should  be 
bled,  if  practicable,  while  under  the  influence  of  an  anaesthetic.  As 
soon  as  the  cat  is  quite  asleep,  the  femoral  vessels  may  be  exposed 
as  directed  for  coarse  injections  (Fig.  39).  and  the  V,  femoralis 
divided.  When  the  venous  flow  slackens,  the  artery  may  be  opened. 
In  this  way  most  of  the  blood  in  the  larger  vessels  is  removed,  and 
preservation  is  facilitated. 


118  ANATOMICAL    TECHNOLOGY. 

§  280.  (1)  Freely  Opening  the  AMomen,— This  is  sometimes,  as 
when  collecting  in  the  lield,  the  only  practicable  method.  The  ab- 
domen is  opened  by  a  longitudinal  incision  a  little  dextrad  of  the 
meson,  never — as  commonly  directed — on  the  meson  itself.  A  sec- 
ond incision  is  to  be  made  at  a  right  angle  with  the  first,  extending 
to  the  dextral  margin  of  the  abdominal  cavity ;  these  two  incisions 
are  shown  in  Fig.  76,  but  the  transverse  one  should  not  cross  the 
meson. 

The  specimen  is  to  be  placed  in  52-67  per  cent,  alcohol,  the  hand 
introduced,  and  the  viscera  lifted  and  moved  slightly,  so  as  to  per- 
mit the  penetration  of  the  liquid  to  all  parts ;  cotton  may  be  inter- 
posed. The  liver  especially  should  be  displaced,  and — unless  its 
preservation  is  especially  desirable — most  of  it  should  be  removed, 
the  cholecyst  (gall  bladder)  being  left. 

§  281.  This  method  is  much  more  efficacious  if  combined  with 
the  third,  as  follows  : — 

The  rectum  is  compressed  so  as  to  expel  its  contents  'per  anum, 
and  the  small  intestine  treated  in  like  manner,  if  its  contents  seem 
to  be  considerable.  The  stomacli  is  manipulated  and  compressed 
so  as  to  expel  its  contents  through  the  mouth.  A  slit  about  1  cm. 
long  is  then  made  in  the  free  surface  of  the  duodenum  near  the 
stomacli,  and  alcohol  injected,  first  through  the  pylorus  into  the 
stomach,  and  then  into  the  small  intestine,  so  as  to  fill  both  it  and 
the  large.  The  escape  of  the  alcohol  from  the  anus  may  be  pre- 
vented by  a  plug  of  cotton.  For  all  injections  of  alcohol,  a  rub- 
ber bulb  syringe  is  more  convenient  than  one  with  a  piston.  After 
injecting,  it  should  be  thoroughly  rinsed  out  with  water. 

The  lungs  may  be  filled  with  alcohol  by  passing  a  curved  canula 
attached  to  a  rubber  tube  from  the  mouth  through  the  glottis,  or 
by  opening  the  trachea. 

§  282.  (2)  Injection  of  52-67  per  cent.  Alcohol  into  the  Thorax 
and  Abdomen. — This  is  less  efficacious  than  the  other  methods,  but 
may  be  adopted  when  it  is  desirable  to  mutilate  a  specimen  as 
little  as  possible,  as  in  making  a  permanent  prei)aration  of  an  entire 
animal. 

The  incisions  for  the  introduction  of  the  canula  should  be  made 
obliquely,  so  as  to  leave  a  valvular  orifice  which  is  less  apt  to  per- 
mit the  escape  of  the  injected  liquid.  Both  sides  of  the  thorax 
should  be  injected.  Of  course  this  method  is  more  efficacious  if 
combined  with  the  third. 


INJECTION    OF   ALCOHOL    INTO     THE    ARTERIES,  119 

§  283.  (3)  Injection  of  B'BSl  per  cent.  Alcohol  into  tJie  Stomachy 
Intestine,  and  Lungs.— If  the  left  hypocliondrium  is  prominent,  or 
if  it  is  known  that  there  is  much  food  in  the  stomach,  the  entire 
abdomen  should  be  compressed,  so  as,  if  possible,  to  expel  the  con- 
tents through  the  mouth.  Pressure  of  the  abdomen  just  cephalad 
of  the  pubes  will  probably  expel  part  of  the  contents  of  the  large 
intestine,  and  most  of  the  rest  may  be  washed  out  with  water  intro- 
duced from  a  syringe  or  from  a  faucet.  Alcohol  should  then  be 
injected  into  the  abdomen,  as  directed  in  §  282,  or  the  cavity  may 
be  opened,  as  directed  in  §  280.  In  the  latter  case,  both  the  stomach 
and  small  intestine  may  be  tilled  from  the  duodenum.  In  the 
former,  alcohol  may  be  injected  into  the  large  intestine  through  the 
anus,  and  into  the  stomach  from  the  mouth.  The  anus  should  be 
plugged  with  cotton  to  retain  the  alcohol ;  if  the  stomach  is  filled 
only  moderately,  the  alcohol  will  probably  be  retained  by  it.  The 
lungs  may  be  filled  in  either  of  the  two  ways  mentioned  in  §  281. 

■p  Of  course,  neither  of  the  three  measures  above  described  is 
of  direct  service  in  preserving  the  membral  muscles  or  the  brain. 
These  parts  are  immediately  reached  by  the  alcohol  only  according 

^^Ko  the  fourth  method,  which  is  efficacious  for  all  parts,  but  somewhat 

^^■pQore  complicated  than  the  other  methods. 

^B     §  284.    (4)  Injection  of  Alcohol  into  the  Arteries. — This  should 
^H>e  done  in  all  cases  when  practicable,  or  unless  there  are  special 
^Bbbjections.     With  entire  animals,  or  the  cephalic  or  caudal  halves, 
there  is  no  practical  difficulty ;  with  smaller  portions,  as  the  head 
or  a  single  limb,  it  may  be  necessary  to  tie  or  secure  with  compress- 
ors other  vessels  than  the  one  injected,  so  as  to  prevent  the  escape 
of  alcohol ;  but  in  some  cases  even  this  may  be  omitted,  the  injec- 
tion being  done  in  a  dish,  so  that  the  escaping  alcohol  is  saved. 
The  following  directions  apply  particularly  to  the  cat: — 
If  the  entire  animal  is  to  be  preserved,  provide  at  least  2  liters 
of  84-95  per  cent,  alcohol  and  a  syringe  and  canula  of  appropriate 
size.     After  bleeding  (§  279),  close  the  vein  by  a  ligature  both  cen- 
trad  and  peripherad  of  the  point  of  division,  and  have  ready  a  small 
compressor  for  aj)plication  to  the  artery.     Inject  the  alcohol  into 
the  A.  femoralis^  as  directed  for  plaster  (see  Chap.  III.). 

Inject  the  alcohol  slowly,  so  as  to  give  it  time  for  penetrating 
the  smaller  vessels,  and  stop  as  soon  as  the  resistance  is  decidedly 
increased,  lest  the  vessels  be  ruptured.  This  last  precaution  is 
indispensable  if  a  plaster  or  gelatin  injection  is  to  be  made  afterward. 


120  ANATOMICAL     TECHNOLOGY, 

Place  a  small  compressor  on  the  artery  just  centrad  of  the  point 
of  injection,  and  withdraw  the  canula.  At  least  two  hours  should 
elapse  before  dissection  is  begun  or  an  injection  made  with  plaster 
or  gelatin.  In  the  interval  the  hair  may  be  clipped  (see  Chap.  YI.). 
After  clipping,  if  no  other  injection  is  to  be  made,  the  animal  may 
be  placed  in  alcohol,  42-55  per  cent. 

§  285.  If  only  the  cephalic  half  of  the  body  is  to  be  preserved, 
not  more  than  one  liter  of  alcohol  may  be  needed,  and  the  operation 
of  abdominal  transection .  should  be  carried  as  far  as  to  open  the 
abdomen  and  puncture  the  diaphragm  (§  238). 

Then,  in  place  of  removing  the  viscera  at  once,  proceed  as  fol- 
lows : — 

Grasp  the  rectum  as  far  caudad  as  possible,  and  force  its  con- 
tents cephalad.  Place  two  ligatures  on  it  (Fig.  41),  about  one  cm. 
apart,  and  cut  between  them. 

With  the  scissors  and  tracer  divide  the  mesentery  of  the  large 
intestine  and  that  of  the  small  intestine,  to  a  point  opposite  the 
cephalic  end  of  the  left  kidney  (Fig.  101,  ren). 

Pass  a  strong  thread  from  this  point  around  the  stomach  and 
liver,  1-2  cm.  from  the  diaphragm,  and  tie  it  very  firmly.  The  lig- 
ature should  cut  deeply  into  the  substance  of  the  liver. 

With  the  tracer  expose  the  aorta  opposite  the  caudal  end  of  the  left 
kidney.  Open  the  aorta  as  directed  (Chap.  lY.)  for  the  A.femoralis. 
Inject  alcohol  as  directed  (§  284)  ;  then  inject  alcohol  into  the  lungs 
as  directed  in  §  281.  Kemove  the  abdominal  viscera  by  an  incision 
1-2  cm.  caudad  of  the  ligature,  taking  care  not  to  displace  the  latter. 

§  286.  Treatment  of  Special  Organs  and  Tissues. — The  blood 
should  be  washed  off  with  water  or  weak  brine.  Yery  vascular 
parts,  like  the  liver  or  spleen,  should  be  gently  manipulated  so  as 
to  expel  most  of  the  blood. 

In  respect  to  the  strength  of  alcohol  required,  the  soft  parts 
form  three  groups,  as  follows  : — 

•  Brains^  embryos^  the  liver ^  spleen^  the  glands^  and  most  inver- 
tebrates should  be  laid  upon  cotton  in  natural  attitudes,  first  in 
alcohol  of  52-67  per  cent.  ;  after  two  days  in  95  per  cent.,  for  a 
week  ;  lastly,  for  exhibition  or  storage,  in  75-95  per  cent. 

Muscular  organs,  including  the  heart  and  alimentary  canal, 
nmy  be  hardened  and  permanently  preserved  in  42-55  per  cent. 
The  same  strens-th  is  ada^:)ted  to  most  entire  animals. 


AMOUNT    OF   ALCOHOL    REQUIRED.  121 

Ligaments^  hones^  and  cartilages  should  be  placed  in  42-55  per 
cent,  for  two  days,  and  then  kept  in  22-30  per  cent. 

When  the  same  specimen  contains  two  or  more  of  these  kinds  of 
organs,  the  strength  of  the  alcohol  should  be  adapted  to  the  more 
perishable,  provided  these  latter  are  to  be  fully  preserved. 

For  injection  into  the  viscera  or  abdomen,  52-67  per  cent.  ;  for 
arterial  injection,  84-95  per  cent.,  is  to  be  preferred,  but  any 
strength  above  30  per  cent,  would  be  of  some  service. 

While  hardening,  specimens  should  be  kept  in  a  cool  place. 

§  287.  Fresh  Specimens  should  not  be  in  contact  with  the  sides 
of  the  vessel.  In  order  that  all  parts  may  be  reached  by  the  alco- 
hol, the  specimen  should  be  suspended  so  as  to  hang  freely,  or  cot- 
ton or  ''excelsior"  interposed  between  the  jar  and  parts  which 
would  be  in  contact  with  it,  or  the  specimen  jar  laid  upon  one  side, 
and  shifted  daily  for  a  week,  so  that  no  part  of  the  specimen  is  in 
contact  for  more  than  24  hours.  With  well-preserved  specimens, 
this  precaution  need  not  be  observed. 

§  288.  Flexible  Specimens. — If  it  is  desirable  that  flexible  spe- 
cimens should  harden  without  contortion,  they  should  be  suspended 
from  the  cover  of  the  jar,  or  the  jar  itself  laid  upon  the  side,  as  sug- 
gested in  §  287  ;  it  is  safer  to  place  the  jar  upon  a  tray.  The  mouth 
end  should  be  slightly  raised  and  very  securely  closed. 

§  289.  Amount  of  Alcohol  Required. — With  fresh  specimens  the 
alcohol  should  not  be  less  than  twice  the  volume  of  the  specimen. 
The  results  are  more  satisfactory  if  the  ratio  is  as  4  : 1.  The  smaller 
amount  may  be  more  safely  used  with  specimens  when  alcohol  has 
been  injected  into  the  arteries  (§  286). 

A.  Specimens  which  have  been  once  saturated  with  alcohol  may  be  stored  or  placed 
on  exhibition  in  the  minimum  quantity  required  to  cover  them  ;  in  this  way  a  single  jar 
or  can  may  hold  a  large  number  of  specimens.  But  fresh  or  partly  preserved  specimens, 
especially  of  viscera,  should  have  plenty  of  space  and  abundance  of  alcohol.  Noverthe 
less,  experienced  collectors  are  sometimes  led  to  fill  a  jar  with  fresh  specimens,  in  the 
hope,  apparently,  that  the  inevitable  laws  of  decay  will  be  overruled  in  their  favor.  In 
most  cases,  a  single  well-preserved  specimen  is  of  more  value  to  science  than  ten  which 
have  been  insuiTiciently  cared  for.     What  is  worth  preserving  at  all  is  worth  preserving  icell. 

B.  With  museum  specimens,  and  for  exhibition,  the  odor  of  the  alcohol  is  less  impor- 
tant ;  but  the  clearness  and  strength  are  essential. 

C.  Old  alcohol,  whether  filtered  or  not,  may  be  used  for  storage,  and  for  the  pri- 
mary treatment  of  some  fresh  specimens. 

§  290.  Provisional  Preparations. — It  is  not  always  possible  or 
even  desirable  to  make  the  flnal  preparation  of  a  part  upon  a  fresh 
specimen,  or  immediately  upon  the  reception  of  one  in  alcohol.     In 


122  ANATOMICAL    TECHNOLOGY. 

these  cases,  however,  if  the  scope  of  the  final  preparation  is  deter- 
mined, most  of  the  parts  not  involved  may  be  removed  at  once,  thus 
saving  alcohol  or  storage  room,  and — if  the  specimen  is  fresh — insur- 
ing the  more  complete  access  of  the  alcohol.  This  measure  is  par- 
ticularly important  in  the  case  of  viscera  or  massive  muscular  organs, 
and  especially  the  brain  of  large  animals  and  man.  Even  with  the 
brain  of  the  cat,  if  the  aulic  region,  for  instance,  is  to  be  examined, 
it  is  well  to  remove  the  dorsal  and  lateral  parts  of  the  hemispheres. 

§  291.  Deterioration  of  Alcohol. — During  its  use  upon  speci- 
mens, alcohol  is  subject  to  four  kinds  of  deterioration  :--- 

It  may  become  colored  by  solution  of  coloring  matters  ;  turbid 
from  the  suspension  of  small  particles  ;  offensive  from  the  solution 
of  malodorous  matters ;  and  weaJc  from  the  evaporation  of  the 
pure  alcohol,  the  impartation  of  alcohol  to  the  specimen,  the  ab- 
straction of  water  from  the  specimen,  and  the  absorption  of  mois- 
ture from  the  atmosphere. 

§  292.  Purification. — Aside  from  distillation  for  the  sake  of 
strengthening,  alcohol  may  be  purified  and  improved  in  three  ways : 
settling  ;  filtration  for  clearing  ;  filtration  for  deodorizing. 

%  293.  Settling.— Lei  the  alcohol  stand  for  a  few  hours  undis- 
turbed. Place  a  second  jar  close  to  it,  so  that  the  first  need  not  be 
carried,  and  pour  the  alcohol  into  it  very  carefully,  and  without 
reversing  the  tilt  until  the  dregs  begin  to  approach  the  mouth.  If 
the  alcohol  is  less  than  20  per  cent.,  or  if  the  dregs  are  very  foul, 
they  should  be  thrown  away.  But  usually  the  dregs  should  be 
poured  into  a  more  slender  jar,  and  allowed  to  settle  a  second  time. 

§  294.  Filtration  for  Clearing.— When  alcohol  is  simply  some- 
what turbid,  as  usually  is  the  case  after  the  settling,  or  if  its  in- 
tended use  does  not  require  deodorizing,  the  following  process  is 
sufficient :  Push  some  cotton  into  the  narrow  part  of  a  large  tunnel, 
set  the  tunnel  into  a  jar,  and  cover  it  closely.  According  to  the 
compactness  of  the  cotton  will  the  alcohol  filter  through  more  or 
less  rapidly,  and  with  greater  or  less  change  of  color  and  clearness. 
The  same  cotton  should  not  be  used  a  second  time. 

A.  Clearinor  may  be  effected  at  the  same  time  with  deodorizing,  if  the  perforated  lid 
of  the  filter  to  be  described  is  covered  with  muslin,  and  if  one  or  more  layers  of  muslin 
are  so  placed  that  the  alcohol  must  pass  through  them  before  reacliing  the  animal  charcoal. 

B.  During  the  filtration  of  alcohol,  unless  it  is  conducted  into  a  receiver  with  a  mouth 
just  large  enough  to  receive  the  discharging  end  of  the  funnel,  or  the  tube  connected 
therewith,  let  these  pass  through  a  hole  in  a  metal,  wooden,  or  pasteboard  cover  of 
the  jar.  ^ 

1 


^H^^^^  ALCOHOL     VAPOR.  123 

^K  §  295.  Filtration  for  Deodorization  and  Decoloration, — This 
^^requires  the  use  of  animal  charcoal^  and  should  follow  the  settling 
and  clearing  already  described. 
b  Any  kind  of  water  filter  containing  animal  charcoal  may  be 
used,  but  the  simpler  and  cheaper  forms  are  sufficient,  and  the  char- 
coal should  be  capable  of  renewal.  Such  is  the  earthenware  filter 
made  for  water  under  the  direction  of  our  colleague,  Prof.  A.  A. 
Breneman,  and  for  sale  by  Messrs.  Rankin  &  Son  of  Ithaca.  Un- 
less the  alcohol  is  clear,  the  perforated  lid  should  be  wrapped  in  a 
cloth,  and  two  or  more  layers  of  cloth  placed  over  the  top  of  the  fil- 
ter, resting  on  the  lid,  so  that  the  alcohol  may  be  cleared  of  sus- 
pended impurities  before  it  reaches  the  charcoal.  In  the  absence 
of  a  proper  filter,  a  bag  of  the  charcoal  may  be  pushed  firmly  into 
a  large  tunnel ;  the  tunnel  for  this  purpose  should  have  the  smaller 
end  larger  than  usual. 

§  296.  Crystalline  Deposits. — From  some  specimens,  especially  brains,  strong  alcohol 
extracts  substances  wliicli  are  precipitated  as  white  crystals  when  the  percentage  of  alco- 
hol is  diminished  or  the  temperature  lowered.  The  resulting  turbidity  and  clouding  of 
the  glass  require  a  thorough  washing  of  the  specimen  and  the  jar,  and  the  renewal  of  the 
alcohol.  The  old  alcohol  should  settle  in  a  cool  place,  and  then  be  filtered  through 
cotton.     Even  after  filtering,  it  should  be  used  only  for  hardening  and  storage. 

When  two  grades  of  "  old  alcohol,"  whether  filtered  or  not,  are  mixed,  the  deposits 
above  mentioned  are  liable  to  occur ;  hence,  if  a  clear  mixture  is  desired,  a  trial  should  be 
made  first  with  small  quantities  of  the  liquids. 

§  297.  Strengthening. — So  far  from  increasing,  the  strength  of  alcohol  is  likely  to  be 
reduced  by  the  processes  of  filtration  and  settling,  especially  unless  precautions  are  taken 
against  evaporation.  A  slight  improvement  may  be  effected  by  treatment  with  quick- 
lime, and  distillation  is,  of  course,  an  efficient  means.  The  readier  method,  however,  is 
simply  to  add  to  the  weaker  spirit  enough  95  per  cent,  alcohol  to  impart  to  the  mixture 
the  required  strength  (§^  271,  272). 

When  alcohol  is  purchased  at  retail,  none  should  be  wasted.  But  if  it  is  obtained  free 
of  tax,  it  is  sometimes  cheaper  to  throw  away  the  weaker  grades,  especially  the  dregs  after 
settling,  rather  than  to  spend  much  time  in  their  improvement. 

§  298.   Alcohol  Vapor..— The  antiseptic  and  preservative  prop- 
erties of  the  vapor  of  alcohol  may  be  utilized  in  two  ways  : — 

(1)  Upon  Fresh  Specimens. — When  a  fresh  specimen  is  to  be  dissected  somewhat  rap- 
idly, say  within  one  week  in  warm  weather,  or  two  or  three  in  cold,  it  will  keep  with 
little  change  if  placed  in  a  close  vessel  at  the  bottom  of  which  is  enough  95  per  cent,  alco- 
hol to  keep  the  atmosphere  completely  saturated  vi^ith  the  vapor.  In  these  cases  the  skin 
should  be  removed  only  as  needed,  and  the  exposed  parts  covered,  when  not  under  exam- 
ination, with  cloths  wrung  out  in  alcohol. 

(2)  Alcoholic  Specimens. — Any  specimen  which  has  been  acted  upon  throughout  by 
alcohol  will  keep  almost  indefinitely  in  the  vapor.  Hence,  in  some  cases,  especially  where 
a  specimen  is  under  daily  dissection,  after  it  has  been  fully  saturated  with  alcohol,  the 


124 


ANATOMICAL   TECHNOLOGY. 


latter  may  be  poured  off,  and  a  small  amount  of  strong  alcohol  left  at  the  bottom  of  the 
jar. 

In  this  case,  however,  if  water  or  the  wetting  liquid  has  been  applied  to  the  specimen, 
a  little  alcohol  should  be  poured  over  it  whenever  it  is  returned  to  the  jar,  or  that  which 
is  already  at  the  bottom  may  be  shaken  up  so  as  to  moisten  the  surface. 

§  299.  Methyl  Alcohol. — This  is  more  often  called  wood  spirit  or  wood  naphtha.  Its 
odor  is  unpleasant,  and  it  is  not  used  as  beverage.  In  England  it  is  said  that  no  tax  is 
imposed  upon  a  mixture  containing  11  per  cent,  of  methyl  alcohol.  In  this  country  it  is 
not  subject  to  tax,  but  costs  about  $1.50  per  gallon.  According  to  Giinther  (A,  697),  it  is 
less  efficient  than  ethyl  alcohol  as  a  preservative,  at  least  for  fishes.  Hence,  when  ethyl 
alcohol  can  be  had  free  of  tax,  there  is  no  object  in  using  the  methylic  variety  ;  even  when 
the  former  costs  its  full  retail  price,  unless  large  quantities  were  wanted,  the  saving  in 
cost  would  hardly  compensate  for  the  unpleasant  smell  of  the  wood  spirit. 

§  300.  Wickersheimer's  Liquid. — Several  formulae  for  making 
this  preservative  have  been  published  in  this  country,  as,  e.  g.,  in 
''The  Popular  Science  Monthly,"  March,  1880,  p.  717  ;  "  The  Med- 
ical Kecord,"  April  17,  1880,  and  April  30,  1881,  p.  501. 

In  the  last  named,  it  is  stated  that  the  original  formula  has  been  altered,  and  that 
Messrs.  Poetz  &  Flohr  of  Berlin  prepare  two  kinds,  one  intended  for  injections,  and  the 
other  for  immersing  bodies.     Their  composition  is  as  follows  : — 


Arsenious  acid 

Sodium  chloride 

Potassium  sulphate. 
Potassium  nitrate.  . . 
Potassium  carbonate 

Water 

Glycerin , 

Wood  naphtha 


Immersion. 

12 

grams. 

60 

" 

150 

« 

18 

tt 

15 

" 

10 

liters. 

4 

X 

According  to  the  previous  article  in  the  "  Record,"  the  various  salts  are  to  be  dissolved 
in  the  boiling  water,  and  the  solution  is  to  be  cooled  and  filtered  before  the  other  two 
liquids  are  added.  It  is  probable  that  the  cheaper  glycerin  will  answer,  and  that  ordinary 
(ethyl)  alcohol  is  to  be  preferred  to  the  methylic  variety  which  is  specified. 

Application. — Preparations  that  are  to  be  preserved  dry  are  immersed  in  the  liquid  for 
6-13  days  according  to  size,  and  then  dried  in  the  open  air. 

Hollow  organs,  like  the  lungs,  must  be  filled  with  the  liquid,  then  laid  in  a  vessel  of 
the  same,  and  afterward  distended  with  air  and  dried. 

Our  own  experience  with  this  liquid  does  not  enable  us  to  give  a  decided  opinion  as  to 
its  merits.  We  are  disposed  to  think  that  it  will  answer  a  good  purpose  with  preparations 
of  the  ligaments,  and  of  hollow  viscera  where  flexibility  is  desired.  With  dry  inflated 
preparations,  the  cheaper  and  simpler  arseniate  of  soda  is  equally  eSicacious,  while  all 
ordinary  "  wet  preparations"  are,  in  our  opinion,  more  surely  and  conveniently  preserved 
by  alcohol 

§  301.  Chloral  Hydrate.— A  solution  of  this  substance  has  been  used  by  Dr.  W.  W. 
Keen  and  some  other  anatomists.     The  results  seem  to  be  satisfactory  in  most  respects 


TEMPORARY  STORAGE.  125 

so  far  as  concerns  man  and  otlier  Vertebrates,  but  less  so  with  tlie  Invertebrates,  at 
least  as  reported  by  Prof.  A.  E.  Verrill  in  a  letter  to  Dr.  Keen. 

Dr.  Keen  has  published  two  papers  upon  the  subject  {1  and  2),  and  kindly  permits  us 
to  print  the  following  brief  statement  of  his  experience  up  to  November  1,  1881  :  — 

"  As  to  the  strength  of  the  solution,  I  should  use  20-30  grains  to  the  ounce  of  water. 
[This  is  4-6  per  cent.,  or  in  the  proportion  of  1  gram  gf  chloral  to  24-16  cc.  of  water.] 
For  the  Invertebrates  and  for  vegetable  tissues,  my  own  experience,  though  limited,  is 
favorable.  It  preserves  vertebrate  organs,  excepting  the  brain,  for  a  few  years  at  least. 
I  have  had  no  failure,  and  some  of  my  specimens  are  now  nine  years  old.  The  colors  are 
rather  less  affected  than  by  alcohol.  The  jars  do  not  need  to  be  hermetically  sealed,  hence 
the  specimens  are  always  accessible.  The  specimens  are  also  less  apt  to  dry  when  exposed. 
The  cost  of  the  solution  is  much  less  than  that  of  alcohol  on  which  the  tax  is  paid.  For 
the  preservation  of  human  subjects  for  dissection,  it  is  most  excellent,  excepting  that 
it  will  not  keep  them  very  long  in  hot  weather,  and  is  not  well  adapted  for  keeping  them 
over  the  summer.  For  use  in  cool  and  cold  weather,  and  especially  for  the  dissection  of 
nerves,  it  holds  its  own." 

The  foregoing  statements  from  so  distinguished  an  anatomist  certainly  warrant  a  care- 
ful trial  of  chloral ;  our  own  experience  is  as  yet  too  limited  for  the  publication  of  the 
results. 

§  302.  Brine. — A  saturated  solution  of  rock  or  dairy  salt  is  sometimes  used  alone  for 
the  temporary  preservation  of  anatomical  material ;  it  is  said  to  be  more  efficacious  when 
the  specimen  is  previously  injected  with  a  saturated  solution  of  arseniate  of  soda.  In  one 
of  the  leading  medical  schools  of  this  country  this  plan  is  successfully  and  economically 
follow^ed  for  keeping  human  subjects  even  through  the  summer  months, 

§  303.  Exhibition  and  Storage  of  Alcoholic  Specimens. — As 
was  stated  in  §  262,  while  alcohol  is  a  perfectly  efficient  preservative 
so  far  a.s  concerns  all  vertebrates,  its  cost,  volatility,  and  corrosive 
action  necessitate  certain  measures  which  may  be  conveniently  dis- 
cussed in  connection  with  the  general  subject  of  the  storage  and 
exhibition  of  specimens. 

§  304.  Temporary  Storage. — For  this  purpose,  and  for  brief 
trans j)ortation,  alcoholic  specimens  may  be  placed  in  vessels  made 
of  wood  or  earthenware  or  any  kind  of  metal ;  but  vessels  so  cm- 
ployed  should  be  carefully  examined  as  often  as  once  a  month,  so 
as  to  guard  against  evaporation,  leakage,  or  rusting. 

Leakage  or  evaporation  are  readily  detected  from  the  diminution  of  alcohol  or  tho 
dampness  of  the  bottom  of  the  vessel  or  of  the  floor,  but  rustiafj  may  not  be  apparent  until 
loss  or  damage  has  occurred.  When  alcoholic  specimens  are  kept  in  tin  ware,  the  metal 
is  certain,  S3oner  or  later,  to  be  corroded  at  some  point  of  contact  with  a  specimen.  A 
mass  of  rust  is  formed  which  may  prevent  the  escape  of  the  alcohol  so  long  as  the  speci- 
mens are  undisturbed.  But  this  rust  is  liable  to  be  dislodged  by  any  movement,  or  even 
by  a  blow  upon  the  side  of  the  vessel,  and  thus  permit  the  escape  of  the  alcohol. 

§  305.  Leakage  from  Imperfect  Glass  Vessels. — Small  jars  and  vials  sometimes  have 
small  holes  or  cracks  which  escape  notice  at  the  time  of  filling,  but  which  permit  the  loss 
of  alcohol  and  the  damage  of  the  contents.  In  some  cases,  part  of  the  bottom  of  a  small 
jar  may  be  so  thin  that  it  is  pulled  off  by  simply  adhering  to  the  paint  of  a  shelf. 


126  A  NA  TOMICA  L     TECHNOLO  G  T. 

%  306.  Corks  should  be  used  only  for  brief  transportation  or  temporary  storage.  The 
bL'st  of  them  are  insufficient  barriers  against  either  evaporation  or  leakage,  and  the  poorer 
ones  should  not  be  used  at  all  with  specimens.  Corks  may  be  rendered  more  secure  by 
soaking  in  oil,  or  covering  over  with  vaseline,  or  with  a  solution  of  paraflfine  in  benzine, 
benzole,  or  turpentine.     Rubber  stoppers  are  sometimes  used. 

§  307.  Glass  Dishes  and  Boxes. — The  anatomist  has  use  for  glass  dishes  of  almost  every 
size.  A  few  sizes  are  kept  in  stock  by  Messrs.  Berge  (A,  No.  257),  and  Whitall,  Tatum  & 
Co.  (A,  No.  2265).  Covers  for  them  may  be  cut  from  window  glass,  or  these  or  other 
sizes  may  be  ordered  to  have  the  edges  ground  for  the  reception 
of  covers  ground  near  the  edge. 

The  covered  box  shown  in  Fig.  31  is  very  useful  for  the  hard- 
ening of  brains  and  other  small  specimens.  The  largest  size  ad- 
vertised by  the  firms  above  mentioned  (Nos.  202  and  2590)  has  a 
capacity  of  nearly  500  cc,  and  costs  $3.80  per  dozen. 

The  covers  of  these  boxes  and  dishes  do  not  fit  accurately,  and 
their  contents  should  be  under  constant  supervision. 

§  308.  Metal  Boxes. — As  the  name  implies,  the  box  usually 
differs  from  the  jar  or  the  can  in  its  relatively  greater  horizontal 

Fir     OH    rovFKFn    ^^*^^^*  ^^^  ^^  having  a  cover  which  is  coextensive  with  the  box, 

Glabs  Box  •    x  25  •    ^"^  ^^  readily  removed  and   replaced.     The  accessibility  of   the 
o  gQ/^^  '    contents  thus  compensates  partly  for  the  evaporation  of  the  alco- 

hol which  must  occur  in  some  degree.  The  cover  should  fit 
closely  and  have  a  wide  flange,  but  such  a  box  should  be  under  constant  supervision. 
Large  boxes  should  be  supported  by  an  outer  box  of  wood. 

For  the  preservation  of  cats  while  under  occasional  examination,  a  box  of  galvanized 
iron  may  be  60  cm.  long,  40  wide,  and  25  deep.  An  entire  cat  may  rest  in  it  lengthwise, 
and  either  the  cephalic  or  caudal  half  crosswise.  Around  the  inside,  half  way  from  the 
bottom,  extends  a  ledge  on  which  may  be  laid  a  metal  plate  perforated  with  holes  2-3 
cm.  in  diameter.  On  this  plate  may  be  placed  a  second  tier  of  specimens,  which  are  thus 
kept  from  pressing  upon  those  at  the  bottom.  If  preferred,  the  bottom  may  contain  only 
alcohol,  the  vapor  of  which  will  suffice  for  the  keeping  of  the  specimens  upon  the  plate, 
provided  they  have  been  already  thoroughly  saturated  with  alcohol.  The  box  may  be 
supported  upon  bosses  or  upon  short  movable  legs.     The  cost  of  such  a  box  is  $4-$5. 

§  309.  Exhibition  or  Permanent  Storage. — For  these  purposes, 
and  for  transportation  occupying  more  than  a  month,  alcoholic 
specimens  can  be  safely  entrusted  only  to  tightly  closing  vessels  of 
glass,  copper,  zinc  or  galvanized  iron.  Of  course,  glass  must  be 
used  for  exhibition  ;  it  is  also  cheaper  than  metal  for  tightly  closing 
vessels,  provided  the  risk  of  breakage  is  not  regarded. 

§  310.  Metal  Cans. — Three  kinds  of  metal  cans  are  useful  in  connection  with  alco- 
holic specimens.  For  bringing  alcohol  from  the  barrel,  and  for  containing  the  supply  for 
current  use,  the  ordinary  five-gallon  oil  can  is  well  adapted,  especially  if  provided  with  a 
faucet  from  which  the  alcohol  may  be  drawn  into  jars  without  lifting  or  tipping  the  can. 
The  small  gallon  or  half-gallon  can  is  desirable  for  pouring  the  alcohol  into  smAll  vials. 
These  cans  may  be  made  of  tin,  but  copper  is  more  secure. 

Screw-top  Cans. — For  the  permanent  storage  of  alcoholic  specimens,  especially  if  occa- 
sional moving  is  necessary,  copper  cans  with  screw-tops  are  desirable.     They  are  more 


EXHIBITION    OB    PERMANENT   STORAGE. 


127 


expensive  than  jars  of  the  same  capacity,  but  are  less  subject  to  injury,  especially  during 
transportation. 

A  convenient  size  has  the  following  dimensions  :  Height,  30  cm.  ;  diameter,  40  cm.  ; 
diameter  of  the  orifice,  26  cm. ;  capacity,  30-35  liters.  The  rings  of  the  screw-top  are  made 
of  brass,  and  should  not  weigh  over  1300  grams.  The  bottom  should  be  protected  from 
abrasion  by  bosses.  (At  the  Museum  of  Comp.  Zoology  in  Cambridge  each  can  is  enclosed 
in  a  wooden  case  which  facilitates  handling  and  may  be  used  in  transportation.)  The  edge 
of  the  cover-ring  is  notched  for  the  admission  of  the  iron  bar  with  which  it  is  screwed  or 
unscrewed.  Such  a  can  costs  Sl0-$13 ;  this  is  more  than  the  cost  of  a  glass  jar  of 
equal  capacity,  but  the  laiter  is  liable  to  break,  especially  during  transportation,  while  the 
can  is  practically  indestructible. 

§  311.  Glass  Jars. — With  the  exceptions  indicated  in  tlie  fore- 
going sections,  glass  is  to  be  preferred  for  all  alcoholic  specimens. 
Glass  jars  may  be  considered  in  five  groups  :  fruit  jars ;  specimen 
jars  with  covers ;  specimen  jars  with  neck  and  ground  glass  stop- 
pers ;  welted  jars  ;  compressed  jars. 

§  312.  Fruit  Jars. — There  are  many  styles  of  these,  but  most  of  them  are  made  of 
more  or  less  opaque  glass.  The  orifice  is  seldom  more  than'  5.5  cm.  in  diameter.  They 
are  thus  unsuited  for  exhibition  or  for  holding  wide  specimens  ;  but  their  cheapness  and 
strength  adapt  them  well  for  the  storage  and  transportation  of  such  specimens  as  they 
will  contain. 


% 


Fig.  32.— Wide  Mouthed  Spectmen  Jars  with  Cover;  §  312 


§  313.  Wide  Mouthed  Jars  with  Covers — (Fig.  32). — These  are  made  on  the  general 
pattern  of  the  "  Millville  "  fruit  jar,  but  are  of  clear  glass,  and  have  mouths  nearly  as 
wide  as  the  jars  ;  the  cover  has  a  7'ing  from  which  specimens  may  be  suspended.  Messrs. 
Whitall,  Tatum  &  Co.,  in  addition  to  what  is  said  in  their  catalogue  (A,  2600),  will  send  a 
price  list  of  13  sizes,  ranging  from  4x3  in.  to  23  x  9.  The  following  special  lengths  of 
standard  widths  have  been  made  by  the  same  firm  at  the  following  prices  for  each  jar : 
18  X  3  in.,  $1.15  ;  23  x  4,  $2.05  ;  32  x  4,  $3.30  ;  these  tall  jars  are  provided  with  a  "  foot." 

These  jars  arc  of  course  less  handsome  than  the  glass  stoppered  kind,  but  their  strength 
and  cheapness  well  adapt  them  for  museum  and  laboratory  use. 


128 


ANA  TOMICAL    TECHNOL  OGY. 


§  314.  Glass  Stoppered  Jar«.— These  are  made  to  order  by  any  extensive  glass  manu- 
factory. The  Dorflinger  Glass  Company,  White  Mills,  Wayne  Co.,  Pa.,  issue  a  price  list  of 
51  diflerent  sizes,  ranging  from  3  x  1  in.  to  23  x  7. 

§  315.  Welted  Jars— (Fig.  33). — With  the  specimen  jars  above  described,  the  neck  is 
strengthened  by  a  constriction.  This  involves  one  of  two  alternatives  :  either  the  speci- 
men must  be  more  or  less  compressed  in 
entering  or  leaving  the  jar,  or  the  body 
of  the  jar  is  needlessly  large.  With 
some  kinds  of  specimens  these  are  not 
very  serious  objections.  But  with  brains 
and  embryos  it  is  desirable  that  all  pres- 
sure should  be  avoided,  and  also  that 
they  should  be  close  to  the  side  of  the 
jar.  For  such  specimens  the  jars  should 
be  of  uniform  diameter  throughout,  and 
the  requisite  thickening  at  the  mouth 
may  be  gained  by  a  welt. 

The  size  represented  in  Fig.  33  is 
adapted  to  the  brain  or  the  heart  of  the 
cat.  Its  inside  measures  are  4  cm.  wide, 
and  6  cm.  to  the  lower  border  of  the  part 
which  is  ground  for  the  stopper.  A 
smaller  size  of  the  same  height,  but 
only  3  cm.  in  diameter,  is  adapted  for 
either  half  of  the  brain.  Both  sizes  are 
made  to  order  by  Messrs.  Whitall,  Ta- 
tum  &  Co.  for  $2.n0  per  dozen. 

§  316.  Compressed  Jars.— The  ordi- 
nary circular  jar  is  poorly  adapted  for  iha 
display  of  flat  specimens  like  frozen  sec- 
tions and  some  fishes.  Messrs.  Whitall, 
Tatum  &  Co.  have  molds  for  two  sizes  cf 
compressed  jars  similar  to  the  photog- 
raphers' "  bath."  They  are  15  cm.  high 
and  21  or  12  cm.  wide.  The  larger  cost 
$12  per  dozen,  and  the  smaller  $6.  The 
tops  are  level  and  ground  off  for  thin 
glass  covers,  which  may  be  cemented  on. 
The  covers  cost  a  small  sum  in  addition 
to  the  price  of  the  jars. 


Fig.  33.— Welted  Vial  for  the  Brain  or 

Heart  op  the  Cat  ;  slightly  reduced  ;  §  314 


§  317.  Cleaning  Jars.— When  large  enough,  jars  should  be 
washed  on  the  Inside  with  a  sponge.  If  they  will  not  admit  the 
hand,  the  washing  may  be  done  with  a  swab  made  by  tying  a 
sponge  upon  the  end  of  a  stick,  or  with  the  bottle  brushes,  one  of 
which  is  shown  in  Fig.  34.  For  long  jars  and  large  tubes  there  are 
bottle  brushes  with  long  handles  ;  or  a  wire  may  be  attached  to  the 
handle  of  a  short  brush  ;  or  the  ring  of  the  handle  may  be  cut  off, 


DISPLAY    OF    ALCOHOLIC    SPECIMENS.  129 

and  the  end  of  the  wire  let  into  a  hole  in  a  stick  of  the  desired  length. 
If  the  jar  is  greasy,  it  may  he  cleaned  perfectly  by  means  of  the 
liquid  soap  (§  248). 

After  washing,  glass  jars  should  be  well  rinsed  with  clean  water, 
and  dried  with  a  soft  but  not  linty  towel,  and  finally— if  for  the 
exhibition  of  specimens — polished  inside  and  out  with  a  bit  of  old 
silk  or  chamois  leather. 


Fig.  34 — Bottle  Brush  ;   reduced  ;  §  316. 

§  318.  Display  of  Alcoholic  Specimens.— Of  course  the  alco- 
hol should  be  clear  and  the  jar  clean ;  but  as  the  jars  are  commonly 
cylindrical  while  many  specimens  are  more  or  less  compressed,  the 
surface  of  the  specimen  is  sometimes  undesirably  distant  from  the 
side  of  the  jar,  and  the  image  is  distorted  by  the  intervening  liquid. 
When  the  compressed  jars  mentioned  in  §  315  are  not  available,  a 
smaller  bottle  or  jar  of  clear  glass  may  be  introduced  so  as  to  crowd 
the  specimen  against  one  side  of  the  jar.  The  inner  jar  must  be 
loaded  with  lead  or  filled  with  alcohol  or  water  to  such  an  extent  as 
to  just  sink  it  in  the  alcohol.  If  water  is  used,  the  smaller  jar  must 
be  very  tightly  closed.     See  Appendix,  §  1456. 

As  a  rule,  an  exhibition  jar  should  contain  only  one  specimen. 

§  319.  Packing  Alcoholic  Specimens  for  Transportation. — 
There  are  certain  precautions  of  general  application,  but  the  details 
vary  according  to  the  nature  of  the  specimens  and  the  conditions  of 
transportation. 

In  most  cases  the  specimens  should  be  packed  before  the  alcohol 
is  poured  in,  and  the  vessel  should  always  I^q  filled. 

Unless  a  pail  is  used,  or  a  box  or  basket  with  an  unmistakable 
handle,  and  ''This  side  up"  prominently  inscribed,  the  package 
should  be  prepared  for  any  position. 

In  respect  to  transportation,  specimens  may  be  grouped  as 
coarse^  delicate,  and  scaly. 

Coarse  Specimens. — Under  this  head  come  most  entire  examples 
of  the  larger  number  of  vertebrates.     These,  or  their  firmer  parts, 
may  be  packed  with  no  precaution  other  than  to  fill  the  vacancies 
with  hay  or  ''  excelsior"  before  introducing  the  alcohol. 
9 


130  ANATOMICAL    TECHNOLOGY. 

Scaly  Specimens,— Ko^i  ''fishes"  and  some  Reptiles  sliould  be 
wrapped  in  gauze  or  netting,  or  any  porous  cloth  or  soft  paper. 
The  wrapper  should  be  secured  with  a  string. 

Delicate  Specimens. — The  delicacy  may  be  due  to  smallness  or 
softness,  or  to  the  presence  of  projecting  parts  which  are  liable  to 
injury. 

Tlie  safest  way  is  to  put  each  specimen  in  a  separate  vial  or  jar 
quite  full  of  alcohol,  or  in  a  small  box  with  saturated  cotton  which 
may  be  immersed  in  a  larger  jar  or  can. 

When  several  delicate  specimens  are  to  be  packed  in  the  same 
vessel,  they  should  be  separated  by  layers  of  cotton  thoroughly 
saturated  with  alcohol.  After  the  alcohol  is  x>oured  in,  the  jar 
should  stand  for  an  hour  at  least  to  allow  time  for  settling.  If 
any  occur,  more  cotton  should  be  put  in. 

Packing  without  Alcohol. — When  the  time  of  transmission  by 
mail  or  express  is  short,  specimens  may  be  safely  sent  if  covered 
with  a  layer  of  alcoholic  cotton,  then  wrapped  in  rubber  sheeting, 
and  packed  in  a  wooden  or  metal  box,  or  in  a  vial  properly  pro- 
tected. 

Secure  Closure  of  Vessels. — Always  important  with  alcoholic 
specimens,  this  is  essential  before  transportation.  In  all  cases  the 
vessel  should  be  laid  on  its  side  or  stood  upon  tlie  upper  end  after 
closing,  so  as  to  determine  the  possibility  of  leakage. 

The  glass  stoppers  should  be  anointed  with  vaseline  or  fine  oil, 
or  a  solution  of  paraffine  in  benzine  or  turpentine,  and  pushed  in 
with  a  slight  screwing  motion.  The  jar  should  then  be  rolled  in 
cloth,  and  the  cloth  turned  tightly  over  the  upper  end  of  the  jar  and 
tied  down  so  as  to  secure  the  stopper. 

The  covers  of  fruit  jars  and  specimen  jars  should  be  screwed  down 
more  firmly  than  usual.  If  possible,  all  jars  should  stand  upriglit 
during  transportation,  and  be  well  packed  in  hay  or  other  soft 
material. 

Welted  Vials  may  be  let  through  holes  in  a  board  so  as  to  be 
supported  by  the  welt.     The  board  may  rest  on  cleets  in  a  box.    ^ 

Packing  boxes  of  tin  are  usually  closed  by  soldering. 

When  earthen  jars  are  used,  the  corks  should  be  pushed  below 
the  level  of  the  rim  of  the  mouth,  and  the  space  filled  up  with  a 
thick  paste  of  plaster  of  Paris. 

§  320.  Miscellaneous  Sug-g-estions.  —  Specimens  having  prominent  appendages, 
whether  arms,  legs,  wingB,  fins  or  spines,  especially  if  they  are  stiff  or  angular,  should 
be  put  into  jars  tail  first,  so  that  their  removal  may  be  unobstructed. 


FROZEN    SECTIONS.  131 

,  This  rule  may  sometimes  require  modification,  as  with  some  "  fishes"  with  delicate  caudal 
fins,  which  might  be  broken  by  the  pressure.  The  specimen  may  be  suspended  from  the 
cover  of  the  jar,  or  the  tail  may  rest  upon  cotton,  or,  finally,  the  jar  may  be  of  such  size  as 
to  permit  the  withdrawal  of  the  specimen  tail  first, 

§  321.  In  some  cases,  when  a  delicate  or  valuable  specimen  is  in  a  jar  or  vial  with  a 
mouth  too  small  for  its  easy  or  safe  extraction,  the  jar  should  be  sacrificed.  Place  itg, 
moulh  just  over  the  edge  of  a  waste  pail  or  box,  and  rap  it  smartly  with  a  hammer  so  aa 
to  break  o£E  the  top.  In  removing  the  specimen,  avoid  the  bits  of  glass  which  may  have 
fallen  into  the  jar. 

When  the  glass  stopper  of  a  jar  cannot  be  removed  in  the  ordinary  way,  tap  the  han- 
dle on  both  sides,  alternately,  with  a  piece  of  wood  or  the  edge  of  a  razor-strop.  If  this 
fails  to  loosen  the  stopper,  or  if  the  handle  breaks  off,  the  jar  may  be  broken  open  as 
directed  above. 

§  332.  In  removing  large  specimens  from  alcohol,  especially  if  the  hair  or  feathers 
remain,  squeeze  the  alcohol  out  with  the  hands,  then  suspend  the  specimen  for  a  sliort 
time  from  a  hook  over  the  jar  or  some  other  receptacle,  and  finally  rinse  it  off  with  a 
stream  of  water.  In  this  way  some  alcohol  is  saved,  dryinor  is  retarded,  and  the  dissector 
avoids  the  odor  and  stimulating  effect  of  the  va])or  of  the  alcohol. 

FROZEi>r  SECTIONS  AND  DISSECTIONS. 

§  323.  Frozen  Sections. — These  are  sections  of  desired  thick- 
ness made  of  a  specimen  which  has  been  frozen  liard  so  that  the 
parts  retain  their  natural  relative  positions. 

Such  preparations  have  been  made  in  Europe  since  1833,  and  in  some  cases  they  have 
been  preserved  as  permanent  preparations.  A  series  of  frozen  sections  of  the  head,  in  the 
museum  of  the  Medical  School  of  Maine,  were  made  by  Dr.  Thomas  Dwight,  and  formed 
the  basis  of  his  work  on  the  heid  (A).     See  also  his  more  recent  work  (B). 

Frozen  sections  of  a  cat  Avere  made  by  us  on  the  21st  of  Jan.,  1879,  and  were  briefly 
described  by  the  senior  author  in  21,     The  method  was  as  follows  : — 

§  324.  The  cat  was  killed  with  chloroform,  the  arteries  injected 
with  red  plaster  and  the  veins  with  blue.  It  was  then  carefully 
supported  in  a  natural  attitude  in  a  box  of  hay,  which  was  placed 
out  of  doors  for  three  days.  The  cat  was  then  perfectly  rigid,  and 
was  rapidly  cut  with  a  sharp  wide-bladed  saw  into  transections 
about  1  cm.  thick.  The  cutting  was  done  in  a  cool  room,  and  each 
section  Avhen  made  was  placed  upon  a  glass  plate,  held  under  a 
gentle  stream  of  water,  and  both  surfaces  freed  from  hair  and  fat 
particles  with  a  soft  nail  brush.  It  was  then  laid  on  one  side  in  a 
dish  of  95  per  cent,  alcohol,  and  put  in  a  cool  place. 

As  the  sections  thawed,  they  were  hardened  by  the  alcohol  so 
as  to  retain  their  form.  Each  was  then  mounted  in  a  compressed 
jar  (§  31 6).  In  some  cases  the  viscera  were  secured  from  falling 
out  by  means  of  insect  pins.  The  cavities  of  the  heart  were  better 
seen  after  the  removal  of  the  plaster. 


**32  ANATOMICAL     TECHNOLOGY, 

§  325.  The  foregoing  is  the  method  followed  in  making  the  transections  shown  in 
Fig.  99  and  100.     The  following  modifications  may  he  desirable  : — 

1.  The  animal  should  he  bled,  when  anaesthetized,  as  directed  in  §  279. 

2.  Prohahly  feawdust  would  ba  better  than  hay  for  support  during  the  freezing. 

3.  The  freezing  was  done  in  winter,  but  artificial  cold  might  be  produced  at  any  time, 

4.  More  satisfactory  results  might  be  reached  by  making  sections  of  only  part  of  a  sin- 
gle individual.  For  example,  the  thoracic  transections  would  be  more  true  to  nature  if 
the  lungs  had  been  filled  with  water  froin  the  trachea  ;  this,  however,  would  have  spoiled 
the  neck.  In  like  manner  the  stomach  and  intestine  or  other  hollow  organs  could  he 
distended  to  their  normal  size. 

5.  For  the  middle  region  of  ihe  abdomen,  including  the  intestines  and  part  of  the 
uterus  and  urocyst,  a  more  satisfactory  result  might  be  reached  by  filling  those  organs 
with  water,  and  keej^ing  up  the  pressure  during  the  freezing.  A  sharp  broad-bladed  knife 
could  be  used  to  transect  the  abdomen  ventre- dorsad,  and  a  narrow-bladed  saw  used  for 
dividing  the  vertebrae. 

§  326.  Frozen  Dissections. — While  frozen  sections  display  the  actual  relative  posi- 
tion of  organs  which  lie  in  a  given  plane,  they  are  unsatisfactory  for  the  same  reason  that 
microscopic  sections  often  are  :  it  is  rare  that  a  complete  view  is  afforded  of  any  aspect  of 
an  organ.  Hence  we  believe  that  for  many  purposes  there  should  be  a  combination  of 
freezing  with  ordinary  dissection.  For  example,  with  a  frozen  cat,  most  of  the  thorax 
could  be  removed  with  the  saw.  Then,  before  thawing  took  place,  all  the  rest  of  the  tho- 
rax could  be  cut  or  nipped  away  so  as  to  expose  the  entire  cephalic  surface  of  the  dia- 
phragm, with  the  cesophagus,  great  vessels  and  nerves  projecting  for  a  short  distance. 
The  pelvic  region  could  then  be  removed,  and  the  preparation  mounted  in  strong  alcohol 
so  as  to  retain  it«  form. 

§  327.  Flexible  Preparations  of  Muscles. — Dr.  Thomas  Dwight  has  published  (7)  the 
results  of  experiments  by  himself  and  others.  We  are  unable  to  contribute  anything  to 
the  subject. 

§  328.  Preparation  of  Hollovr  Viscera. — Aside  from  preserva- 
tion like  other  soft  parts,  the  stomach  and  caecum,  the  lungs,  the 
urocyst  (urinary  bladder),  and  cholecyst  (gall  bladder)  may  be  pre- 
pared by  permanent  inflation  with  air  or  alcohol  so  as  to  display 
their  size,  form  and  subdivisions  with  more  or  less  of  their  texture. 

Since  the  stomach  is  most  frequently  prepared  in  this  way,  the 
following  directions  apply  more  directly  to  it,  but  they  may  be 
readily  modified  for  the  other  organs  named.  The  parts  of  the 
stomach  are  shown  in  Fig.  81. 

§  329.  Removal, — The  viscus  should  be  removed  from  the  body 
as  soon  as  possible  after  death.  If,  however,  the  stomach  or  csb- 
cum  has  been  freed  from  its  contents  as  described  in  §  283,  the 
removal  may  be  longer  delayed. 

There  should  be  left  attached  to  the  viscus  a  portion  of  each 
canal  continuous  therewith,  about  5  cm.  long  if  possible.  With 
large  specimens  this  length  may  be  greater,  and  with  small  ones  it 
must  sometimes  be  less.     To  secure  so  much  of  the  oesophagus  of 


PREPARATION    OF    HOLLOW     VISCERA.  133 

the  cat,  tlie  diaphragm  must  be  cut  through ;  after  division  of  the 
tube,  a  circlet  of  the  diaphragm  may  be  left  attached  thereto. 

§  330.  Cleansing. — The  organ  should  be  manipulated  in  water 
so  as  to  expel  the  contents  and  dislodge  the  mucus  from  the  ental 
surface.  When  possible,  as  with  the  caecum  and  with  the  stomachs 
of  some  of  the  lower  vertebrates,  the  organ  should  be  everted.  In 
any  case  the  ental  surface  should  be  thoroughly  cleansed  with  a 
stream  of  water  from  a  faucet  or  syringe. 

If  desired,  the  capacity  of  the  viscus  may  be  measured  as  di- 
rected in  §  384. 

Normal  salt  solution  should  then  be  thrown  into  the  organ,  and 
it  should  be  allowed  to  soak  in  the  same  for  a  few  hours,  or  until 
the  blood  is  removed.  If  any  part  projects  above  the  surface,  it 
should  be  covered  with  a  layer  of  absorbent  cotton. 

§  331.  Trimming, — After  sufficient  soaking,  expel  the  n.  s.  s., 
and  place  the  organ  upon  a  clean  tray  or  dish.  Provide  two  coni- 
pressors  or  some  linen  thread,  blowpipe,  coarse  forceps  and  coarse 
scissors  curved  flatwise. 

Close  the  free  end  of  the  oesoi3hagus  with  a  compressor  or  liga- 
ture. Into  the  duodenum  introduce  the  blowpipe,  inflate  the  organ 
to  a  moderate  degree,  and  close  the  orifice  with  a  compressor  or  liga- 
ture. If  the  latter  is  employed,  the  orifice  may  be  controlled  by 
the  fingers  of  the  operator  or  of  an  assistant  while  the  thread  is 
applied. 

In  trimming,  the  fat  and  vessels  and  connective  tissue  are  to  be 
grasped  with  the  forceps,  and  cut  off  close  to  the  viscus.  The  con- 
vexity of  the  scissors  must  be  kept  toward  the  organ,  and  care 
taken  not  to  wound  it  with  the  point  of  the  forceps. 

The  subsequent  steps  in  the  operation  vary  according  to  the 
agent — air  or  alcohol — to  be  used  for  the  permanent  inflation. 

§  332.  Distention  with  Alcohol, — This  is  better  adapted  to  the 
lungs,  and  to  delicate  specimens  which  might  not  withstand  the 
pressure  and  manipulation  involved  when  air  is  employed. 

Place  the  organ  in  55-75  per  cent,  alcohol,  in  a  dish,  or  better  in 
the  jar  in  which  it  is  to  be  preserved.  Cut  off  the  ligatured  smaller 
end,  and  secure  in  the  orifice  the  canula  of  a  syringe,  or  a  canula 
connected  by  a  rubber  tube  with  the  canula  of  a  syringe  ;  place  a 
ligature  at  the  orifice  ;  then  distend  the  organ  with  the  same  per 
cent,  of  alcohol.  If  a  bulb  syringe  is  used,  or  if  the  injecting  syr- 
inge is  provided  with  a  cock,  it  is  only  necessary  to  tighten  the  lig- 


134  ANATOMICAL    TECHNOLOGY. 

atnre  at  the  time  of  desired  distension  ;  otherwise,  the  reflux  of  the 
alcohol  may  be  prevented  by  a  small  compressor. 

The  jar  selected  should  be  so  large  that  the  inflated  organ  may 
swim  without  pressure  against  the  sides.  It  may  be  kept  from  the 
bottom  either  by  suspending  it  by  a  thread  from  the  loop  on  the 
jar  cover,  or  by  attaching  a  piece  of  cork  or  a  bulb  of  thin  glass. 

§  333.  Inflation  with  Air,  and  Drying.— This  method  is  less 
expensive,  but  more  complicated : — 

After  trimming,  cleansing,  soaking,  and  trimming  as  above  di- 
rected (§§  330,  331),  the  organ  is  to  be  partly  filled  with  a  saturated 
solution  of  arseniate  of  soda  (§  259),  and  placed  in  tlie  same.  The 
projecting  part  should  be  covered  with  absorbent  cotton,  and  the 
whole  should  be  turned  at  least  once.  According  to  size,  it  should 
remain  in  the  solution  for  from  3-12  hours.  If  left  too  long,  the 
tissues  are  gelatinized  and  rendered  incapable  of  withstanding 
pressure  and  manipulation. 

Exp^l  an}^  liquid  contents  as  completely  as  possible,  and  let  the 
organ  drain  from  a  clean  smooth  surface. 

Select  two  fine-grained  corks  adapted  respectively  to  the  two  ori- 
fices. With  a  rat-tailed  file  girdle  each  with  a  furrow  at  about  the 
middle  of  the  length.  Perforate  the  larger,  and  fit  very  closely  into 
it  a  piece  of  glass  tube  projecting  about  3  cm.  from  the  larger  end. 
Fill  the  grooves  with  mucilage,  and  secure  each  cork  by  winding 
about  it  at  the  level  of  the  groove  a  string  or  rubber  band. 

To  the  glass  tube  attach  a  rubber  tube.  Infiate  the  organ,  and 
apply  a  compressor  near  the  glass  tube.  Put  a  tack  or  a  small 
screw-eye  into  each  cork,  and  suspend  the  organ  from  screw-hooks 
in  a  natural  position,  in  a  warm  but  not  dusty  place.  If  the  organ 
is  large,  or  drags  too  heavily  upon  the  slender  oesophagus  and 
intestine,  support  it  by  bands  of  parchment  or  oiled  paper. 

Connect  the  rubber  tube  with  a  gas  jet,  or  with  the  outlet  of  a 
gasometer,  or  other  apparatus  by  which  continuous  pressure  may 
be  made.  Remove  the  compressor,  and  turn  the  gas  on  cautiously, 
so  as  not  to  distend  the  organ  unduly. 

The  escape  of  gas  will  be  slight,  but  its  accumulation  should 
be  avoided,  and  the  place  well  ventilated. 

If  no  artificial  means  of  inflation  are  available,  air  may  be  blown 
in  from  the  mouth,  or  injected  with  a  syringe,  but  in  these  cases 
constant  attention  is  required  to  prevent  collapse. 


TO   MEASURE   THE   CAPACITY  OF  AN   ORGAN,  135 

When  the  organ  is  perfectly  dry,  the  ends  containing  the  corks 
may  be  cut  off,  and  fresh  corks  secured  with  mucilage  only.  In  at 
least  one  of  the  corks  should  be  a  screw-eye  to  which  the  label  may 
be  attached,  and  by  which  the  specimen  may  be  suspended  from  a 
screw-hook. 

Finally,  by  excising  one  or  more  pieces  of  the  wall  with  a  keen 
scalpel,  the  position  and  shape  of  the  orifices  may  be  displayed. 

A.  Dried  inflated  specimens  should  be  kept  free  from  dust  and  moisture,  in  close  cases, 
or  boxes  or  jars.     They  shoiUd  not  be  Tarnished. 

B.  Inflated  preparations  which  have  been  dried  without  poisoning,  or  have  been  insuf- 
ficiently poisoned,  may  be  sprayed  with  the  solution  of  arseniate  of  soda  by  means  of  an 
atomizer.  This  should  be  done  cautiously  and  over  a  small  area  at  a  time,  lest  the  entire 
organ  collapse. 

■    C.  According  to  a  paragraph  in  the  **  American  Naturalist  "  for  March,  1881,  page  282, 
**  Dry  specimans  may  be  freed  from  parasites  by  spraying  with  anhydrous  sulphurous  acid." 

§  334.  To  measure  the  Capacity  of  an  Organ.— This  may  be 
done  in  either  of  two  ways : — 

1.  The  organ  may  be  filled  with  water  from  a  vessel  of  known 
capacity,  and  the  amount  measured. 

2.  The  organ  may  be  filled,  and  its  contents  allowed  to  escape 
into  a  vessel  and  then  measured. 

In  employing  either  method,  certain  precautions  should  be  ob- 
served : — 

1.  The  organ  should  be  completely  emptied  of  its  contents. 

2.  It  should  not  be  measured  until  after  the  cessation  of  any 
contraction  which  may  exist  at  or  soon  after  death. 

3.  If  possible,  it  should  be  held  by  an  assistant. 

4.  It  should  rest  in  a  dish  of  water  so  that  the  water  used  in 
measuring  may  not  exert  undue  pressure. 

5.  Since  only  the  capacity  of  the  organ  itself  is  desired,  care 
must  be  taken  to  let  the  water  go  no  farther  than  the  outlets.  With 
the  stomach,  for  example,  the  pylorus  should  be  closed,  and  the 
introduced  water  should  not  rise  into  the  oesophagus. 

6.  If  the  organ  is  not  to  be  preserved,  the  pylorus  may  be  tied. 
But  as  tying  injures  the  parts,  a  specimen  which  is  to  be  preserved 
may  have  the  outlet  held  by  an  assistant  or  closed  by  a  compressor 
or  by  other  mechanical  means. 

7.  If  the  cardiac  orifice  is  large,  the  water  may  be  poured  in. 
If  small,  it  may  be  introduced  through  a  tunnel  or  through  a  can- 

.  ula  connected  with  a  syringe.    In  the  one  case  hydrostatic  pressure 


136  ANATOMICAL    TECHNOLOGY. 

must  be  avoided,  and  in  the  other  no  more  force  should  be  used 
than  will  suffice  to  propel  the  water  very  gently. 

8.  If  the  contained  water  is  to  be  measured,  the  organ  should  be 
brought  to  the  edge  of  the  vessel,  and  the  latter  filled  so  that  the 
outlet  of  the  organ  may  be  carried  over  its  edge.  Then  the  contents 
are  to  be  carefully  expressed  into  another  vessel.  In  no  case  must 
the  organ  be  made  to  support  the  weight  of  the  contained  water. 

9.  While  full,  the  organ  should  be  measured  as  to  length,  width 
and  height,  and  as  to  its  girth  at  one  or  more  points. 

§  335.  To  measure  the  Volume  of  an  Organ. — The  following 
method  is  proposed  by  Dr.  H.  P.  Bowditch  (/,  149) :  "  Plunge  the 
organ  into  a  vessel  already  full,  and  measure  the  overflow." 

Of  course  the  full  vessel  must  stand  in  a  dish  from  which  the 
overflow  may  be  collected,  and  the  ordinary  anatomical  tray  will 
not  answer.  In  some  cases,  therefore,  the  following  method,  though 
less  simple,  may  be  more  easily  adopted,  and  the  result  will  be 
almost  equally  exact : — 

Attach  a  cord  securely  to  some  part  of  the  organ.  Place  it  in  a 
vessel,  and  fill  the  latter  with  water.  Then  remove  the  organ  b}^ 
means  of  the  cord,  and  the  amount  required  to  fill  the  vessel  will 
represent  the  volume  of  the  organ.  In  most  cases,  the  space  occu- 
pied by  the  cord  may  be  disregarded. 

General  References  to  the  Preservation  of  Soft  Parts.— The  following  are  in  addi- 
tion to  the  references  given  on  p.  Ill  :— U.  S.  Dispensatory,  13th  ed.,  Art.  Alcohol  ; 
Watts,  A ;  Baley,  A  ;  Gunther,  A,  Appendix  ;  Keen,  1,  2  ;  Dwight,  A,  B,  and  1  ; 
Reeves,  A  ;  Highley,  1 ;  Hyrtl,  A  ;  Mojsisovics,  A,  36-37. 


CHAPTER    IV. 

COARSE      INJECTIONS. 

§  336.  Special  Apparatus  and  Material  : — Acid,  Acetic,  No.  8,  mixed  with  an 
equal  volume  of  water — Aniline  Red  (Magenta)— Aniline  Blue — Beeswax — Berlin  Blue 
(see  §  1449) — Carmine  No.  40 — Chrome  Yellow — Chrome  Green — Cobalt  Blue — Dishes 
(2)  of  100  cc.  capacity — Magenta  or  Aniline  Red — Mixing  Dish,  400  cc.  capacity — Pestle  of 
Wood  or  Porcelain — Pins — Plaster  of  Paris,  Finest  Dental — Red  Lead — Sponge — Syringe 
with  assorted  Canulse — Thread,  Linen  No.  25-35,  Cotton  No.  20 —Turpentine,   Oil  of — 

Iarnish,  Copal — Vermilion,  American  or  Chinese. 
11 


I 


§  337.   The  object  of  injections  is  to  render  the  blood  vessels 
ore  apparent,  and  thus  to  facilitate  their  detection.    The  impor- 
nce  of  a  perfect  familiarity  with  their  position  and  relations  cannot 
be  overestimated  from  the  surgical  and  experimental  standpoints. 


§  338.  Syringe. — A  syringe  is  usually  employed  to  force  the  injecting  mass  into  the 
ood  vessels.  It  should  have  the  following  featurc-s  : — (A)  Ample  capacity,  so  that  one 
ringe  full  will  fill  the  entire  arterial  or  venous  system  of  the  animal  to  he  injected.  Of 
course  this  does  not  apply  to  large  animals  like  horses.  One  of  200  cc.  is  adapted  to  cats. 
(B)  The  piston  of  the  syringe  should  fit  well  and  be  leather  packed  (Fig.  35).  (C)  There 
should  be  canulje  of  various  sizes  corresponding  to  the  different  vessels  to  be  injected. 
The  brass  anatomical  syringes  (Fig.  37,  38)  are  best,  but  quite  expensive. 

Care  of  the  Syringe. — As  soon  as  an  injection  is  finished,  expel  any  remaining 
plaster  into  the  waste  pail.  Then  fill  the  syringe  several  times  with  clean  water  and 
expel  it.  Force  a  part  of  a  syringe  full  through  the  canula,  so  it  may  be  entirely  emptied. 
Finally,  it  is  best  to  unscrew  the  top  of  the  barrel  and  remove  the  piston,  so  that  the  bar- 
rel may  be  entirely  emptied.  Wipe  the  piston  with  an  old  towel  and  oil  the  leather 
packing  before  returning  the  piston  to  the  barrel. 

If  glue  or  wax  mass  is  employed,  the  syringe  should  be  cleaned  with  hot  water. 

If  the  piston  becomes  so  loose  that  the  mass  passes  it  instead  of  being  forced  out 
through  the  canula,  remove  the  piston,  and  make  the  leather  packing  flare  slightly  (Fig.  35). 

If  the  canula  becomes  clogged,  it  may  be  easily  opened  by  using  a  small  knitting 
needle. 

§  339.  White-Metal  Syringe  (Fig.  35). — Syringes  of  this  kind  are  cheap  and  answer 
very  well  for  both  coarse  and  fine  injections.  The  metal  canula  is  much  too  large  to  insert 
in  an  ordin-ary  vessel,  but  that  difficulty  may  be  easily  overcome  by  the  use  of  glass  can- 
ulse (Fig.  36)  and  a  rubber  tube  for  connection  (Fig.  42). 


138 


ANATOMICAL    TECHNOLOGY. 


Barrel. — The  barrel  of  the  syringe  is  the  large  cylindrical  part  in  which  the  piston  fits. 
The  injecting  mass  is  drawn  into  it  by  pulling  the  piston  in  the  direction  of  the  handle. 


Canulcu 


B 


Fig.  35. — White-Metal  Syringe  with  Top  Unscrewed  and  Piston 

Removed  ;    x  .3. 

Canula. — The  canula  is  the  smaller  part  which  serves  to  connect  the  syringe  with  the 
object  to  be  injected. 

Handle. — The  handle  is  a  continuation  of  the  piston.     It  projects  from  the  barrel,  and 
by  it  the  piston  is  moved. 

Piston. — Tiie  piston  of  a  syringe  is  within  the  barrel.     Its  end  should  be  packed  with 
leather,  as  shown  in  the  figure,  so  that  it  will  fit  very  closely. 

Canula  or  Nozzle. — The  canula  serves  to 
connect  the  syringe  with  the  object  to  be  in- 
jected. The  end  should  be  cut  off  obliquely. 
U  It  is  then  like  a  wedge,  and  may  be  inserted 
into  the  vessel  much  more  easily  than  one 
cut  squarely  off. 

eThe  caliber  of  the  canula  should  be  as 
great  as  can  be  put  into  the  vessel  to  be  in- 
jected. For  plaster  injections  (§  341)  the 
canula  should  not  be  less  than  1  mm.  at  its 
narrowest  point, 
A. — Metal  canula  with  lateral  arms  at  the  end  next  the  syringe,  and  a  slight  shoulder 
at  the  small  end. 

B. — A  glass  canula  cut  off  obliquely  at  its  small  end. 
C. — A  glass  tube  drawn  out  for  two  canulae. 

§  340.  To  prepare  glass  canulse,  take  a  glass  tube  about  6  mm. 
in  diameter  and  from  8-10  cm.  in  length,  and  heat  its  middle  evenly 
in  a  Bunsen  flame.  When  the  glass  is  softened,  draw  the  two  ends 
apart  until  the  tube  is  sufliciently  reduced  in  caliber  in  the  middle  ; 
then  after  cooling  make  a  fine  scratch  with  a  file  as  shown  in  C,  and 
the  two  may  be  broken  apart.  AVhen  separated,  grind  the  end  flrst 
on  a  fine  file  with  water  to  make  it  oblique  as  in  A  and  B,  and 
finally  on  the  fine  oil  stone  to  make  it  smooth.  Heat  the  larger  end 
in  the  flame  to  round  the  sharp  edges. 


Fig.  36.— Canula  ;   x  .6. 


INJECTION   31  ASSES. 


139 


In  this  figure  (Fig.  37)  of  the  regular  brass  anatomical  syringe,  are  shown  four  canulae 
of  various  sizes  and  a  separable  stop-cock.     The  stop-cock  fits  upon  the  end  of  the  short 


CODMAN  &  SHURTLEFF. 

BOSTON. 


Fig.  37. — Brass  Sybinge  :  x  .5. 


canula  of  the  syringe,  and  the  canulae  for  insertion  in  the  vessels  fit  upon  the  end  of  the 
stop-cock.  In  most  syringes  of  this  kind  the  stop-cock  may  be  dispensed  with  and  the 
canulae  fitted  directly  to  the  syringe  if  desired. 


I 


INJECTION  MASSES. 


w- — 


Fig.  38.— Small  Brass  Syringe  with 
Removable  Stop-cock  and  Canula 
FOR  Fine  Injections  ;   x  .3. 


§  341.   Plaster  of  Paris  Mass.— The  most  convenient  mass  is 
composed  of  the  finest  plaster  of  Paris  stained  with  carmine  solu- 
tion for  arteries  and  with  Berlin 
I  blue  for  veins.    To  facilitate  the 
Preparation  of  the  mass,  a  quan- 
pty  of  both  colors  should  be  kept 
pa  stock. 
^     §  342.    Carmine    Solution.— 
This  is  prepared  by  grinding  to  a 
paste  4-5  grams  of  carmine  No. 
40  in  20  cc.  of  water  and  then 

dissolving  it  in  50  cc.  of  strong  ammonia.  To  this  solution  is  then 
added  75  cc.  of  glycerin  and  500  cc.  of  water.  After  shaking  well, 
filter  through  fine  flannel  or  absorbent  cotton. 

§  343.  Blue. — Berlin  blue  (§  1449),  a  saturated  aqueous  solution, 
500  cc,  glycerin,  75  cc.  Mix  the  glycerin  and  the  blue,  and  filter 
as  for  red.  The  glycerin  preserves  the  solutions  and  retards  the 
setting  of  the  plaster  (Gage,  1,  717). 

§  344.  Various  Colors— A.  Bed. — Plaster  mass  may  be  well 
colored  by  American  or  Chinese  vermilion,  red  lead  or  a  solution  of 
aniline  red  (magenta) :  Magenta,  2.5  grams  ;  50  per  cent,  alcohol, 

100  cc. 


140  ANATOMICAL     TECHNOLOGY. 

B.  Blue. — The  plaster  mass  may  be  colored  blue  by  cobalt  or 
ultramarine  blue  or  a  solution  of  aniline  blue :  Aniline  blue,  2.5 
grams  ;  50  per  cent,  alcohol,  100  cc. 

O.  Yellow  or  Green. — Employ  chrome  yellow  or  green. 

Permanent  preparations  should  not  be  made  of  an  animal  in- 
jected with  a  mass  colored  by  one  of  the  aniline  dyes,  for  they  are 
soluble  in  alcohol  and  fade  in  the  light.  The  vermilion  and  cobalt 
blue  are  the  most  permanent,  but  the  carmine  and  Berlin  blue  last 
many  years. 

§  345.  Preparation  of  Plaster  Injection  Masses. — The  masses 
should  be  used  immediately  after  preparation,  and  before  the  plaster 
has  time  to  set. 

Approximately  the  same  volume  of  plaster  and  liquid  should  be 
employed  for  ordinary  injections.  If,  however,  one  wishes  the  mass 
to  fill  the  smallest  vessels,  the  liquid  should  be  increased  so  that 
the  ratio  is  as  1-3  or  even  1-3. 

A.  Mass  Colored  with  Carmine. — Measure  out  100  cc.  of  the 
finest  plaster  of  Paris  and  put  it  into  a  mixing  dish,  a  tea  or  coffee 
cup,  that  will  hold  about  400  cc.  Add  to  this^  plaster  about  100  cc. 
of  the  carmine  solution  (§  343),  and  mix  thoroughly  with  a  wooden 
or  porcelain  pestle.  Finally,  add  slowly  and  with  constant  stirring 
the  50  per  cent,  acetic  acid.  Add  the  acid  till  the  color  changes  to 
bright  red  and  the  odor  of  the  acid  in  the  mass  is  quite  perceptible. 
An  excess  of  acid  is  less  injurious  than  a  deficiency. 

B.  Mass  Colored  with  Berlin  Blue. — Plaster  same  as  for  car- 
mine. Add  100  cc.  of  the  Berlin  blue  solution  (§  343),  and  stir  well. 
No  acid  is  necessary. 

C.  Masses  Stained  with  Aniline. — Measure  out  100  cc.  of  plas- 
ter and  put  it  into  the  mixing  dish  as  directed  above;  then  add,  for 
red,  20  cc.  of  the  magenta  solution  and  100  cc.  of  the  undiluted 
glycerin  solution  (§  171).  Stir  thoroughly.  For  blue,  add  50  cc.  of 
the  blue  aniline  solution  and  75  cc.  of  the  15  per  cent,  glycerin. 

D.  Mass  Colored  with  Vermilion  or  Bed  Lead.— Put  25  grams 
of  the  dry  color  into  the  mixing  dish  and  add  25  cc.  of  15  per  cent, 
glycerin.  Grind  the  color  thoroughly  to  crush  all  the  lumps. 
Finally,  add  100  cc.  of  plaster  and  100  cc.  of  15  per  cent,  glycerin, 
and  mix  very  thoroughly. 

E.  Masses  Colored  with  Cobalt  or  Ultramarine  Blue,  Chrome 
Yellow  or  Green.— Emi^^oj  15  cc.  of  the  color,  and  prepare  as 
directed  for  the  vermilion  (§  345,  D). 


WAX    AND    TALLOW   INJECTIONS.  141 

§  346.   Wax   and  Tallow  Masses. —  Wax  Mass. — Beeswax,  2 

parts  ;  Canada  balsam,  2  parts  ;  Vermilion,  2  parts. 

Mix  the  wax  and  Canada  balsam  and  melt  over  a  water  batb. 
Then  grind  the  vermilion  thoroughly  in  a  small  amount  of  mastic 
varnish,  and  add  it  to  the  mixture.  Heat  over  the  water  bath  for 
half  an  hour  or  more.     This  mass  Hows  very  finely.     Hyrtl,  A,  616. 

Tallow  Mass. — Tallow,  900  grams ;  Magnesia  usta  (calcined 
magnesia),  15  grams  ;  Vermilion,  30  grams. 

Grind  the  magnesia  and  vermilion  in  a  small  amount  of  mastic 
varnish  or  turpentine,  before  adding  to  the  melted  tallow.  Harri- 
son, A,  II.,  866. 

§  347.    Practical  Working  of  Wax  and  Tallow  Injections.^ 

First.  The  animal  must  be  warmed  to  38-40°  C.  This  is  best  done 
in  a  large  galvanized  iron  dish  that  may  be  covered  and  the 
water  kept  hot  by  means  of  a  Bunsen  burner  or  in  some  other 
way.  All  the  heating  should  be  done  in  a  water  bath  so  that  no 
burning  may  occur. 

When  the  animal  is  warmed  through  (the  time  required  de- 
pends on  the  size  of  the  animal),  the  canula  should  be  put  in  posi- 
tion (§  358).  Warm  the  syringe  thoroughly  by  filling  it  with  hot 
water  and  slowly  emptying  it.  Warm  the  mass  till  it  is  quite 
fluid,  and  stir  it  well.  If  it  is  not  heated  above  50°  C,  it  will  not 
burn  most  mammalian  tissues.  Fill  the  syringe  with  the  mass  and 
force  it  out,  to  make  sure  the  mass  is  thoroughly  mixed.  Then  lill 
the  syringe,  connect  it  with  the  canula  in  the  vessel,  and  force  the 
mass  in  rather  more  rapidly  than  directed  for  plaster  (§  359),  but 
the  operation  should  not  be  so  long  continued. 

One  cannot  inject  Fislies  or  Amphibia  with  wax  mass,  as  Hyrtl  has  well  said,  for  the 
heat  required  to  warm  the  subject  and  the  mass  would  cook  the  tissues.  For  them,  starch 
or  some  other  cold  flowing  mass,  or  gl  ue  which  remains  liquid  at  a  low  temperature,  must 
be  us3d. 

After  the  injection  is  finished,  the  animal  should  remain  in  a 
cool  i)lace  for  at  least  three  or  four  hours  before  the  dissection  is 
commenced. 

§  348.  Choice  of  Specimen  for  Injection. — A  young  adult  and 
lean  cat  is  best.     It  should  be  fasting  except  for  special  purposes. 

§  349.  Time  of  Injection. — Inject  before  the  rigor  mortis  comes 
on.  If  that  is  impossible,  it  is  better  to  put  it  into  warm  water 
(35°  C.)  for  an  hour  to  make  the  muscles  flexible.    This  is  not  abso- 


142 


ANATOMICAL    TECHNOLOGY. 


lutely  necessary,  "but  the  smaller  vessels  will  be  more  likely  to  be 
injected  if  the  muscles  are  flexible. 

§  350.  Arteries  to  Inject  for  a  Complete  Injection  of  the  Ani- 
mal, named  in  order  of  Desirability :  A.  femoralis,  A.  carotidea, 
Aorta  (Fig.  39,  101). 


Fig.  39.— Femoeal  Vessels;    x.5. 

§  351.   Veins  to  Inject:   V.  femoralis,  V.  jugularis  externa, 
Postcava  (Fig.  101).     As  to  Cleanliness,  see  §  199. 

EJECTION  OF  THE  FEMOEAL  VESSELS. 


§  352.   Posture. — Place  the  cat  dorsicumbent,  as  in  Fig.  76. 
§  353.   Exposure.— Grrasp  the  meros  close  to  the  trunk  with  the 
pollex  and  index,  and  the  femur  will  be  felt  in  an  interval  between 


t 


DISSECTION,  143 

the  muscles  on  the  cephalic  side  (upper  side  in  the  present  posture). 
The  femoral  vessels  are  just  entad  of  the  skin  and  connective  tissue, 
and  parallel  with  the  femur  in  the  proximal  third  of  the  meros. 
To  expose  the  vessels,  lift  a  triangular  flap  of  skin  (Fig.  39). 

§  354.  Parting  the  Hair. — Before  making  the  incisions,  wet  the 
hair  well  with  a  sponge,  and  with  a  comb  part  it  along  the  lines 
where  the  incisions  are  to  be  made.  Incisions  can  be  very  much 
more  neatly  and  easily  made  after  the  skin  is  thus  exposed. 

Fig.  39. — Preparation. — The  arteries  were  injected  caudad  from  the  aorta  abdoiuinalis 
(§  101) ;  then  the  veins  were  injected  from  the  V.  poplitaea  in  the  popliteal  space,  in  the 
concavity  of  the  knee  (Fig  30),  After  half  an  hour  the  triangular  flap  of  skin  was  dis- 
sected  free  and  turned  to  the  left  and  secured  by  a  pin  passing  throujrh  its  tip  into  the 
muscles  of  the  left  meros.  All  the  fat  and  connective  tissue  were  then  removed  with  the 
tracer,  fine  forceps  and  scissors. 

A.  (Arteria)  femoralis — Femoral  artery.— This  is  the  continuation  of  the  A.  iliaca 
extorna  (S^  101  \     It  is  between  the  vein  and  nerve, 

Ann.  abd.  ext.  Annulus  abdominalis  exterior  s.  ectalis — External  (ectal)  ingui- 
nal ring. — This  is  the  ectal  opening  of  the  inguinal  canal  through  which  the  chorda  sper- 
matica  passes  into  the  abdominal  cavity. 

C.  sp.  Chorda  spermatica — Speraiatic  cord. — This  is  a  bundle  of  structures  passing 
from  the  testis  to  the  abdominal  cavity.  It  is  composed  mainly  of  the  spermatic  artery 
nd  vein  and  the  vas  deferens. 

Lg.  P.  Ligamentum  Poupartii  (Poupart's  ligament.  Crural  arch). — This  is  a  liga- 
mentous or  aponeurotic  arch  dorsad  of  which  pass  the  femoral  vessels, 

N.  (Nervus)  cruralis  anterior  (Anterior  crural  nerve).— This  is  the  largest  branch 
f  the  lumbar  plexus  of  nerves.  It  is  both  muscular  and  cutaneous  in  distribution. 
Quain,  A,  I,  604. 

Scarpa's  Triangle. — This  is  the  triangular  depression  on  the  cephalic  side  of  the 
meros  in  which  the  femoral  vessels  are  found.     Quain,  A,  I,  454 ;  Gray,  A,  546. 

V.  (Vena)  femoralis — Femoral  vein. — The  femoral  vein  is  continued  by  the  V.  iliaca 
mmunis  as  it  passes  into  the  abdomen.  It  is  caudad  of  the  artery  as  the  two  pass  dorsad 
the  Ligamentum  Poupartii,  but  ventrad  of  it  in  the  meros. 


m 


§  355.   Dissection. — With  the  tracer  and  fine  forceps,  very  care- 
fully dissect  the  artery  free  from  the  vein,  nerve  and  connective  tis- 
ue  for  about  2  cm.  from  the  abdominal  wall.    Be  very  careful  not 
:o  stretch  the  artery.     It  seems  only  about  half  the  diameter  of  the 
vein. 

§  356.  Incisions  in  the  Vessel. — When  the  artery  is  free,  put 
the  handle  of  a  scalpel  wet  in  15  per  cent,  glycerin  entad  of  it  (Fig. 
40) ;  with  a  Cliarriere  scalpel  then  make  a  V-shaped  incision  that 
will  include  about  one  third  the  width  of  the  vessel  as  it  is  flattened 
on  the  scalpel  handle.  Cut  entirely  through  to  the  scalpel  handle 
on  which  the  vessel  rests.  The  Charriere  should  be  held  pen-like 
(Fig.  63),  and  so  that  the  apex  of  the  V  (Fig.  40)  shall  point  periph- 


144 


ANATOMICAL    TECHNOLOGY. 


erad.    A  more  convenient,  but  less  safe  way  for  beginners,  is  to 

employ  scissors  as  sliown  in  Fig.  40.     It  is 
Vessel.  sometimes  desirable  also  to  cut  the  Ffrom 

apex  to  base  as  shown  in  Fig.  42.  Enlarge 
the  opening  in  the  vessel  by  inserting  the 
probe  wet  with  15  per  cent,  glycerin. 

§  357.  Ligatures. — AVhile  the  probe  is 
still  in  the  vessel,  with  the  fine  forceps 
grasp  the  middle  of  a  thread  30-40  cm. 
long  and  push  the  loop  through  entad  of 
the  vessel,  and  at  a  point  centrad  of  the 
incision  (Fig.  40).  The  loop  .may  then  b(? 
grasped  by  the  fingers  or  forceps  and 
drawn  through  as  far  as  desired. 

Instead  of  pushing  the  thread  through 
as  directed  above,  one  may  put  the  forceps 
entad  of  the  vessel  first  and  grasp  the  looj) 
and  pull  it  through.     Bernard,  A,  263. 

When  the  thread  is  through  as  far  as 
desired,  cut  the  loop.  The  thread  nearest 
the  incision  is  for  tying  the  canula  in  the 
vessel ;  the  other  is  for  ligaturing  the  ves- 
sel when  the  injection  is  finished.  Both 
threads  should  be  loosely  tied  in  a  sur- 
geon's knot  (Fig.  41),  so  that  they  may 
be  quickly  tightened. 

§  358.  Introduction  of  the  Canula. — 
When  the  threads  are  prepared,  remove 
the  probe  from  the  vessel,  select  a  canula 
of  the  proper  size,  that  is,  as  large  as  can 
be  put  into  the  vessel,  and  make  sure  that 
it  is  open  by  blowing  into  it  or  forcing 
water  through  it  with  the  syringe.  Hav- 
ing wet  its  small  end,  put  it  into  the  ves- 
sel so  that  the  injection  will  be  centrad. 
To  insert  the  canula,  grasp  one  edge  of 
the  V-shaped  incision  with  the  fine  for- 
ceps and  pull  it  open.      Now  introduce 

the  canula  and  push  gently  with  a  slight  twisting  motion.    At  the 
same  time  pull  with  an  equal  force  in  the  opposite  direction  with  the 


Fig.  40.— Incisions  and  Prep 
aration  for  ligaturing 

X.5. 


Fig.  41.— Double  Ligature 
xL 


MAKING    THE    INJECTION. 


145 


VtfssfiL 


fine  forceps  by  which  the  edge  of  the  incision  is  grasped.  As  soon 
as  the  canula  is  in  the  vessel,  let  go  the  edge  of  the  slit  and  grasp 
the  whole  vessel  where  it  sheaths  the  canula.  Pinch  quite  firmly, 
and  pull  while  the  canula  is  pushed  into  the  vessel  for  about  1  cm. 
Tiie  canula  being  smooth  slips  into  the  vessel  notwithstanding  the 
j)ressui'e  of  the  forceps.  Rest  the  elbows  on  the  table  to  steady 
the  hands. 

The  canula  should  be  very  smooth,  and  the  serrations  on  the  for- 
ceps must  not  be  too  deep  or  they  will  cut  the  vessel.  The  canula 
may  be  polished  as  directed  for  instruments 
(§  183),  and  any  roughness  may  be  removed 
by  the  oil  stone. 

As  soon  as  the  canula  is  properly  in- 
serted, put  the  thread  nearest  the  incision 
(Fig.  40)  so  that  it  will  press  on  the  canula 
within  the  vessel,  and  then  tighten  ihQ  knot. 
If  the  canula  has  an  enlargement  near  the 
end  (Fig.  36,  A),  it  cannot  escape  when  tied  as 
in  Fig.  42.  If  there  is  no  enlargement  or  a 
glass  canula  is  used,  the  thread  must  be  tied 
to  some  part  of  the  canula  outside  the  vessel. 
If  there  are  transverse  projections  (Fig.  36, 
A),  the  thread  should  be  tied  around  one  of 
them.  If  a  glass  canula  is  used,  tie  as  shown 
in  Fig,  42.  All  the  threads  should  be  knot- 
ted in  a  hard  knot  finally,  and  the  ends 
should  be  cut  within  a  centimeter  of  the  last 
knot. 

§  359.  Making  the  Injection. — As  soon 
as  the  canula  is  secured  in  the  vessel,  fill  the 
syringe  partly  with  water  or  normal  salt  solu- 
tion, connect  it  with  the  canula  in  the  vessel,  and  force  a  little  of 
the  liquid  in  to  make  sure  the  canula  is  open  and  properly  inserted. 
In  connecting  the  canula  and  syringe,  grasp  the  canula  with  one 
hand  and  hold  it  firmly  while  making  the  connection.  Bo  the  same 
in  separating  tbem. 

After  forcing  a  small  amount  of  water  into  the  vessel,  separate 

the  canula  and  syringe,  expel  the  water,  and  then  prepare  the  mass 

as  directed  above  (§  345).     Stir  the  mass  thoroughly,  and  then  fill 

t!ie  syringe,  beimr  sure  to  lower  the  syringe  as  the  mass  is  drawn 

10 


Liqa^ures- 


Canula  of 
smnoe/ 


Fig.  42. — Inserting 
Securing  Canula  : 


AND 

<5. 


146  ANATOMICAL    TECHNOLOGY. 

into  it,  so  that  no  air  may  get  into  the  syringe.  Connect  the  syr- 
inge with  the  canula  which  is  in  the  vessel  (§  358).  Hold  the  canula 
firmly  with  one  hand  and  pull  toward  the  syringe  as  the  mass  is 
forced  into  the  vessel.  Be  sure  that  the  vessel  is  not  looped  or 
twisted  in  the  least,  but  drawn  peripherad  just  enough  to  straighten 
it.  Force  the  piston  down  steadily  and  continuously  ;  do  not  allow 
it  to  stop  until  the  injection  is  finished.  If  the  canula  becomes 
clogged,  the  resistance  will  be  complete,  and  there  will  be  an 
entire  absence  of  the  elastic  feeling  which  comes  from  the  distended 
arteries.  Very  often  the  canula  may  be  opened  by  pulling  the  pis- 
ton back  a  little  and  then  forcing  it  down  quickly. 

One  can  tell  only  by  experience  when  the  injection  is  finished. 
The  vessels  are  usually  filled,  however,  when  the  piston  returns 
slightly  on  remitting  the  pressure.  If  the  injection  is  carried  too 
far  or  the  pressure  is  too  great,  the  semilunar  valves  (Fig.  102)  are 
liable  to  be  ruptured  and  the  heart  filled,  or  some  vessel  may  give 
way. 

§  360.  Tying  the  Vessel. — As  soon  as  the  injection  is  finished, 
tie  the  vessel  with  the  thread  provided  for  the  purpose  (Fig.  42), 
draw  back  the  piston  slightly,  and  then  cut  the  string  holding  the 
canula  in  the  vessel  and  remove  the  canula. 

§  361.  Cleaning  the  Canula,  Syringe  and  Mixing  Dish. — Do 
this  immediately  after  the  injection  is  finished  before  the  plaster  has 
time  to  set.  Expel  the  plaster  remaining  in  the  syringe  into  the 
waste  pail ;  then  fill  the  syringe  with  water  and  empty  it.  Do  this 
several  times,  and  then  force  some  clean  water  through  the  canula. 
Finally,  it  is  best  to  unscrew  the  top  of  the  syringe  and  pour  out 
any  liquid  that  has  passed  the  piston. 

Throw  any  plaster  remaining  in  the  mixing  dish  into  the  waste 
pail  and  clean  out  the  dish  very  thoroughly.  The  plaster  must  not 
be  thrown  into  the  sink  lest  it  should  set  and  clog  the  waste  pipe. 
The  dissection  may  commence  in  half  an  hour  after  the  injection  is 
finished. 

§  362.  Injection  of  the  Femoral  Vein— Fig.  39. — ^Dissect  the 
vein  free  for  2  or  3  cm.  from  the  abdominal  wall  as  described  for 
the  artery  (§  353).  Compress  the  vein  and  force  the  blood  centrad. 
It  will  pass  verj  readily  and  leave  the  vein  nearly  empty.  Now 
press  on  the  vein  just  as  it  enters  the  abdomen  and  try  to  force  the 
blood  peripherad.  There  will  be  seen  a  bulging  in  the  vessel  ex- 
tending about  .5  cm.  from  the  body  wall.     There  are  two  valves  at 


INJECTION    OF    THE     VARIOUS     VESSELS.  147 

the  peripheral  end  of  the  enlargement  which  prevent  the  flow  of 
blood  in  this  direction.  Make  a  V-sliaped  incision  in  the  vein  cen- 
trad  of  the  valves  in  the  same  manner  as  directed  for  the  artery 
(§  356).  Compress  the  thorax  and  hold  the  cat  upright  to  facilitate 
tlie  flow  of  blood. 

When  as  much  blood  as  possible  is  removed,  insert  the  canula 
(Fig.  42),  and  inject  plaster  prepared  as  directed  (§  359).  ^ 

The  injection  should  be  made  as  directed  for  the  arteries,  but  it 
should  be  remembered  that  the  walls  of  the  veins  are  thinner  than 
those  of  the  arteries,  and  hence  the  pressure  must  be  more  moderate. 

On  account  of  the  valves  in  the  systemic  veins  (Fig.  102),  it  is  necessary  to  inject  cen- 
trad.  The  injection  may  be  made  to  pass  the  valves  sometimes,  however,  by  manipulating 
the  part  while  the  mass  is  forced  in. 

§  363.  Injection  of  the  Aorta  Abdominalis. — Posture  and 
Exjposure, — Place  the  cat  dorsicumbent,  and  then  expose  the  ab- 
dominal viscera  as  shown  in  Fig.  76,  and  directed  hereafter. 

Turn  the  four  flaps  aside,  and  then  turn  the  intestines  to  the  left. 
The  right  kidney  will  be  seen  on  the  right  side,  and  in  the  middle 
line  i\\Q  postcava  (Fig.  101). 

§  364.  Dissection,  and  Insertion  of  Canula,— W\i\i  the  tracer 
tear  away  the  mesentery  (Fig.  80)  and  connective  tissue  in  the  middle 
line  opposite  the  caudal  margin  of  the  right  kidney.  The  aorta  is 
dorsad  and  sinistrad  of  the  postcava  in  this  region,  and  between 
the  two  great  psoas  muscles.  Free  it  fcr  2-3  cm.  Make  a  V-shaped 
incision  with  scissors  (Fig.  40),  insert  and  fasten  the  canula,  and 
inject  as  directed  above  (§  359). 

If  only  the  cephalic  part  of  the  body  is  to  be  studied,  it  is  necessary  to  inject  cephalad 
only,  but  if  the  entire  animal  is  to  be  studied,  one  should  inject  first  cephalad  and  then 
caudad.     The  second  injection  should  be  made  as  soon  as  possible  after  the  first. 

As  soon  as  the  injection  is  made,  the  postcava  should  bo  opened  to  allov/  the  blood  to 
escape. 

§  365.  Injection  of  the  Postcava.— The  exposure  is  the  same  as 
for  the  Aorta  abdominalis.  Inject  as  directed  for  the  V.  femoralis 
(§  362) 

§  366.  Injection  of  the  V.  Jugularis  Externa. — Posture. — Place 
the  cat  dorsicumbent  and  a  block  flatwise  under  the  neck  and 
shoulders.  Rotate  the  head  so  that  the  nose  points  away  from  the 
side  to  be  injected. 

Exposure. — Press  upon  the  throat  and  find  the  larynx  (Fig.  30, 


1^8  A  NA  TOMICA  L     TECHNOL  OGT. 

§  234).  Then  press  upon  the  side  of  the  neck  near  the  head  and  de- 
termine the  position  of  the  wing  of  the  atlas,  diapophysis  atlantalis 
(Fig.  52,  §  229) .  Part  the  hair  along  a  caudo-cephalic  line  from  about 
midway  between  the  wing  of  the  atlas  and  the  larynx,  and  then 
commencing  opposite  the  cephalic  edge  of  the  wing  of  the  atlas, 
carry  an  incision  directly  candad  for  3-5  cm.  Divaricate  the  skin, 
and  the  external  jugular  vein  will  appear,  full  of  blood. 

Injection, — Dissect  the  vein  free  as  directed  for  the  A.  femoralis, 
make  a  Y-shaped  incision,  insert  the  canula,  and  then  remove  as 
much  blood  as  possible,  as  directed  (§  362).  Finally,  inject  with 
blue  plaster  (§  343). 

It  is  impossible  to  fill  the  small  vessels  with  plaster  on  account  of  the  valves  (Fig.  103). 
If  one  wishes  to  inject  the  venous  system  of  the  cat,  it  may  be  done  successfully  in  most 
cases  by  injecting  blue  gelatin  into  the  jugular  or  femoral  vein.    See  Appendix,  §  1450. 

§  367.  Injection  of  the  Arteria  Carotidea. — Posture. — The  pos- 
ture should  be  the  same  as  for  the  V.  jugularis  externa  (§  366). 

Exposure,— Wak.e  an  incision  through  the  skin  as  directed  for 
the  external  jugular  vein  (§  366).  Dissect  up  the  mesal  edge  of  the 
skin  to  the  ventrimeson.  Determine  the  position  of  the  larynx,  and 
then  make  an  incision  2-3  cm.  long  just  laterad  of  the  larynx  and 
through  the  sterno-mastoid  muscle.  Divaricate  the  cut  edges  of  the 
muscle,  and  there  will  be  seen  extending  parallel  with  the  trachea 
the  carotid  artery,  the  vagus  and  sympathic  nerves,  and  the  Y. 
jugularis  interna  (Fig.  101). 

Dissection. — With  the  tracer  and  forceps,  dissect  the  artery  free 
from  the  nerve  and  vein.  Make  a  V-shaped  incision,  insert  the 
canula,  and  inject  centrad  as  directed  for  the  A.  femoralis  (§  359). 

All  the  arteries  of  the  body  will  be  filled  excepting  those  cephalad  of  the  place  of 
injection  on  the  side  injected.  To  fill  those,  one  must  inject  cephalad  after  the  general 
injection  is  made. 

References  to  Coarse  Injections.— Bernard,  A,  191,  262;  Gage,  1,111;  Harrison, 
A,  II,  865  ;  Heath,  A,  547 ;  Hyrtl,  A,  615  ;  Straus-Durckheim,  B,  I,  90;  Mojsisovics,  A. 
15-24. 


CHAPTER    V. 

OSTEOLOGY— THE  STUDY  OP  THE  BONES. 

THE  DETERMINATION  OF  THE  RIGHT  AND  LEFT  WITH  CERTAIN  BONES — SPECIAL  MNH- 
MONICS  OF  THE  HUMERUS — DETALIED  DESCRIPTION  OP  THE  SCAPULA,  HUMERUS, 
CARPALIA,   CLAVICULA,  STERNUM,  COST^,  PELVIS,  VERTEBRA  AND  SKULL. 

I 

§  368.  A  general  description  of  the  whole  skeleton  has  been 
given  on  pp.  87-95.  In  accordance  with  the  general  plan  of  this  work 
as  stated  in  §  1 28,  certain  parts  of  the  skeleton  are  also  described 
somewhat  in  detail,  while  others  are  mentioned  only  incidentally  or 
not  at  all. 

Sooner  or  later,  of  course,  the  student  will  consult  some  complete 
treatise  upon  Human,  Veterinary  or  Comparative  Anatomy,  and  thus 
acquire  the  information  here  omitted.  We  believe,  however,  that 
he  will  do  well  to  make  for  himself  drawings  and  descriptions  of  the 
bones  not  fully  described  here  ;  the  drawings  should  be  in  outline 
or  but  slightly  shaded ;  the  descriptions  should  be  in  two  parts, 
general  and  brief,  and  special  and  detailed. 

DETERMINATION   OF  RIGHT   AND   LEFT. 

§  369.  The  right  and  left  of  paired  bones  may  be  determined 
by  reference  to  a  mounted  skeleton  or  figure.  The  longer  membral 
bones  and  the  parts  of  the  shoulder  and  pelvic  girdles  may  also  be 
distinguished  by  means  of  the  following  special  formulae  : — 

In  all  cases,  except  with  the  scapula,  innominatum  and  fibula, 
the  long  axis  of  the  given  bone  is  placed  Jiorizontally  from  the  left 
to  the  right  of  the  observer,  and  the  distal  end  is  made  to  point  to 

^^e  side  to  icMcTi  the  given  hone  belongs. 

^P  At  the  end  of  the  formula  for  detenuining  the  side  of  the  body 
to  which  a  long  bone  belongs,  are  placed  directions  for  the  recogni- 
tion of  one  of  the  extremities  and  two  of  the  sides  or  aspects  which 
are  not  opposite.  The  end  and  the  sides  not  given  may  then  be 
readily  ascertained.     Finally,  there  are  directions  for  determining 


150  ANATOMICAL    TECHNOLOGY. 

the  aspects  of  the  limbs  as  wholes,  together  with  some  special  mne- 
monics for  the  humerus. 

§  370.  Clavicula — Clamcle,  collar  hone  (Fig.  48). — ^A.  Man. — 
It  should  be  placed  with  the  greater  concavity  up,  the  projecting 
part  of  the  thick,  mesal  or  sternal  end  toward  the  observer ;  then 
the  flattened  lateral  end  will  point  to  the  side  to  which  the  bone 
belongs. 

B.  Cat. — It  should  be  held  with  the  subcylindrical  end  mesad 
and  curving  downward,  the  great  concavity  toward  the  observer ; 
the  flattened  end  will  then  point  to  the  side  to  which  the  bone  be- 
longs. In  young  cats  the  two  ends  are  so  nearly  alike  that  it  is 
difficult  to  determine  right  and  left. 

§  371.  Scapula— Shoulder  blade  (Fig.  43-45).— The  gleno-ver- 
tebral  angle  (§  383)  should  be  held  toward  the  observer  and  the 
glenoid  fossa  down ;  then  the  mesoscapula  will  be  on  the  side  to 
which  the  bone  belongs. 

§  372.  Humerus— (Fig.  46).— The  bone  should  be  held  with  the 
olecranon  fossa  (Fig.  71)  up,  the  epitrochlea  toward  the  observer 
(the  musculo-spiral  groove  in  man  away  from  him).  In  the  cat  and 
many  other  animals,  rarely  in  man  also,  there  is  a  foramen  {Fm. 
epitrocJileare,  Fig.  46),  near  the  caudal  border  of  the  distal  end 
(§  417). 

The  olecranon  fossa,  the  deepest  of  the  distal  fossse  (Fig.  71)  is 
on  the  dorsal  aspect.  The  Foramen  epitrochleare  in  the  cat  and  the 
most  prominent  apophysis  (epitrocTilea)  of  the  distal  end  are  on  the 
caudal  side  in  both  cat  and  man. 

§  373.  Radius— (Fig.  30).— The  bicipital  tuberosity  should  be 
held  down,  the  styloid  process  on  the  side  away  from  the  observer. 
The  styloid  process  is  the  most  distal  part  of  the  bone.  It  is  on  the 
cephalic  side,  while  the  bicipital  tuberosity,  which  is  near  the  prox- 
imal end,  is  mostly  on  the  ventral  side.     The  distal  end  is  the  larger. 

§  374.  Ulna — (Fig.  30). — The  great  sigmoid  cavity  should  be 
held  down,  the  lesser  sigmoid  cavity  from  the  observer ;  then  the 
smaller  end  points  to  the  side. 

The  great  sigmoid  cavity  is  on  the  ventral  aspect  at  the  proximal 
end;  the  lesser  one  is  on  the  cephalic  aspect  just  distad  of  the 
greater  one  and  continuous  with  it. 

§  375.  Innominatum— Pelvic  bone  (Fig.  30,  51). — It  should  be 
•held  with  the  ischiatic  tuberosity  toward  the  observer,  the  pubic 


DETERMINATIOX    OF    EIGHT    AND    LEFT.  .  151 

artliral  facet  down,  the  cotyloid  fossa  looking  to  one  side  ;  the  fossa 
will  be  on  the  side  to  which  the  bone  belongs. 

§  376.  Femur— (Fig.  30).  -The  bone  should  be  placed  with  the 
head  pointing  away  from  the  observer,  the  intercondylar  fossa  or 
notch  down. 

The  nearl}^  spherical  arthral  head  is  situated  at  the  proximal 
extremity  ;  it  faces  approximately  cephalad.  The  longitudinal  con- 
cavity of  the  whole  bone  and  the  intercondylar  fossa  or  notch  are 
on  the  ventral  aspect. 

§  377.  Tibia— (Fig.  30).— It  should  be  held  with  the  tuberosity 
for  the  patellar  ligament  up,  the  malleolus  facing  away  from  the  ob- 
server ;  the  end  bearing  the  malleolus  will  point  to  the  side  to 
which  the  bon^^  belongs. 

The  most  distal  part  (malleolus)  is  on  the  cephalic,  and  the  lon- 
gitudinal concavity  on  the  ventral  aspect. 

§  378.  Fibula— (Fig.  30). — If  the  bone  be  placed  horizontally, 
with  its  distal  extremity  toward  the  observer,  and  the  distal  arthral 
surface  up,  then  the  deep  rough  depression  at  the  latero-distal  mar- 
I  gin  of  the  arthral  surface  will  be  on  the  side  to  which  the  bone  be- 
longs ;  or,  in  grasping  tliis  end  with  the  pollex  and  index,  the  pollex 
of  the  side  to  which  the  bone  belongs  may  be  easily  put  into  this 
depression. 

This  method,  so  far  as  we  know,  was  first  devised  by  G.  S.  Shep- 
pard,  a  student  in  the  anatomical  laboratory  of  Cornell  University. 

The  distal  arthral  surface  is  on  the  cephalic  aspect,  and  the 
depression  for  the  ligament  spoken  of  below  is  at  the  ventro-distal 
edge  of  this  surface. 

The  arthral  surface  of  the  distal  extremity  is  on  the  side,  while 
that  of  the  proximal  extremity  is  nearly  on  the  end.  The  depres- 
sion spoken  of  at  the  distal  end  is  for  the  attachment  of  the  *'  pos- 
terior fasciculus  of  the  external  lateral  ligament"  of  the  anlde. 

§  379.  Determination  of  the  Right  and  Left  with  the  Entire 
Limbs. — The  sides  of  the  whole  arm  may  be  recognized  by  remem- 
bering that  the  capitellum,  radius  and  pollex  (thumb)  are  on  the 
^^cephalic  side,  while  the  olecranon  process  and  fossa  are  on  the 
^fcorsal  side,  and  the  convexity  of  the  elbow  points  dorsad. 
^m  The  sides  of  the  whole  leg  may  be  determined,  since  the  tibia  and 
^Rrimus  (great  toe)  are  on  the  cephalic  aspect,  and  the  convexity  of 
^Bie  knee  faces  dorsad.  (§  80,  219), 


152  ANATOMICAL    TECHNOLOGY. 

%  380.  Special  Mnemonics  of  the  Humerus. — AVith  a  bone* 
having  sucli  numerous  and  important  anatomical  relations,  so  vari- 
ously placed  in  different  animals  and  in  the  same  animal  at  differ- 
ent times,  so  frequently  involved  in  surgery,  and  so  generally  rep- 
resented in  painting  and  statuary,  it  is  very  desirable  that  the  names 
and  relative  positions  of  the  parts  should  be  promptly  remembered. 
The  following  mnemonic  suggestions  may  prove  useful  to  some : — 

Of  the  two  ends  of  the  bone,  proximal  and  distal^  the  former  is 
the  larger  and  has  the  longer  name. 

The  cepJialic  side  is  also  called  radial,  and  both  these  names  ar(^ 
longer  than  the  corresponding  words  caudal  and  ulnar^  whicli 
apply  to  the  opposite  side. 

With  one  exception,  the  principal  features  of  the  cephalic  side 
have  longer  names  than  the  similar  parts  upon  the  caudal  side. 
TrocJiiter,  capitelhtm  and  Fs.  radialis  are  longer  than  irocliin, 
troclilea  and  Fs.  ulnar  is.  The  trochiter  itself  also  is  larger  than 
the  trochin. 

Epicondylus  equals  epitrocMea  in  length,  but  the  latter  is  read- 
ily associated  with  trochlea,  and  itself  suggests  the  name  of  the  Fm. 
epitrochleare. 

In  the  normal  position  of  the  arm,  the  deep  olecranon  fossa 
(Fig.  71)  is  uppermost  with  both  man  and  cat.  With  the  cat  also, 
the  longer  and  more  decided  dorsal  concavity  of  the  bone  as  a 
whole  may  be,  though  somewhat  remotely,  associated  with  the  back 
of  a  saddle  horse. 

§  381.  The  selected  portions  of  the  skeleton  are  here  described 
in  the  following  order,  which  is  mainly  that  of  their  simplicity  : — 

Scapula,  humerus,  ulna,  radius,  carpus,  clavicula,  sternum, 
costse  (ribs),  pelvis,  vertebrae,  and  skull.  The  other  raembral  bones 
and  the  Os  Tiyoides  have  been  briefly  described  in  §§  220-224. 

THE  SCAPULA  (Fig.  30,  43,  44,  45,  67,  74,  75). 

References.— Straus-Durcklieim,  A,  I,  507-509  ;  Parker,  A,  215,  PI.  xxx.  ;  Owen,  A, 
II,  488 ;  Gray,  A,  218-223 ;  Quain,  A,  I,  81 ;  Chauvean,  A,  81  ;  Chauveau  (Fleming),  A, 
72  ;  Flower,  A,  221  and  229  ;  Humphrey,  A,  363-370  ;  Mivart,  B,  89-91  ;  Leyli,  A,  170, 171. 

§  382.  General  Description.— The  scapula  (shoulder  blade  or 
blade  bone)  is  a  flat  irregular  bone  imbedded  in  the  muscles  on  the 
lateral  aspect  of  th3  cephalic  region  of  the  thorax  (Fig.  30,  67,  74, 
75),  and  articulating  with  the  humerus  to  form  the  shoulder  joint. 

As  seen  from  its  ental  or  ectal  aspect  (Fig.  43  and  44),  the  out- 


THE    MARGINS    AND    ANGLES    OF  THE   SCAPULA.  153 

line  of  the  scapula  may  be  characterized  as  either  subtriangular  or 
approximately  semicircular.  The  former  term  is  more  commonly 
employed,  perhaps  because  it  is  more  applicable  to  the  human 
scapula.  But  if  the  two  scapulae  of  the  cat  are  placed  with  their 
straighter  sides  in  apposition,  they  will  be  seen  to  cover  an  area 
w^iich  is  approximately  circular,  although  the  borders  are  more  or 
less  undulating. 

§  383.  The  Margins  and  Angles  of  the  Scapula.— It  is  at  least 
convenient  to  regard  the  scapula  as  triangular,  and  as  presenting 
therefore  three  sides  (margines)  and  three  angles  (anguli). 

The  thicker  (glenoid  or  arthral)  angle  articulates  with  the  hu- 
merus, and  presents  several  elevations  and  depressions  which  will 
be  described  separately.  Its  larger  part  is  occupied  by  a  concave 
surface,  the  F'ossa  glenoidea^  for  articulation  with  the  humerus; 
hence  that  border  of  the  bone  which  is  separated  from  the  fossa  only 
by  its  Up  is  called  the  Mar  go  glenoideus.  Between  the  fossa  and 
the  other  border  springs  a  hook-shaped  projection,  the  Pre.  cora- 
coldeus^  and  the  border  is  thence  named  Mrg.  coracoideus.  The 
intermediate  border  is  called  the  Mrg.  vertebralis  from  its  proxim- 
ity to  the  Coliimna  vertehralis. 

Of  the  borders,  the  glenoid  is  the  longest  and  straightest.  The 
coracoid  is  the  shortest  and  least  regular,  and  its  outline  varies  in 
different  individuals.  According  to  the  observations  of  Parker  (A, 
215,  PI.  XXX.,  Fig.  1-3),  in  the  cat  and  in  some  other  Carnivora  this 
margin  ossifies  from  an  independent  center  and  remains  for  some 
time  separate  from  the  rest  of  the  bone.  The  vertebral  border  is 
intermediate  in  length,  and  presents  a  nearly  regular  curvature. 
With  young  individuals  this  margin  is  cartilaginous,  representing  a 

(suprascapular  but  later  it  becomes  coossilied  with  the  rest. 
I     The  angles^  respectively  more  and  less  obtuse,  formed  by  the 
junction  of  the  vertebral  margin  with  the  other  two,  are  called  coraco- 
vertebral  and  gleno-vertebral. 

The  emargination  of  the  coracoid  border  near  the  neck  of  the 
bone  (at  the  lower  end  of  the  dotted  space  in  Fig.  43)  is  known  as 
the  Inclsura  cor  aco- scapular  is  (Flower,  A,  223).  In  the  human 
scapula  it  is  deeper  and  commonly  called  the  suprascapular  notch, 

^  o84.    Description  of  Fig.  43. — The  ental  aspect  of  an  adult  left  scapula. 
Acromion. — This  is  more  distinctly  seen  in  Fig.  44  and  45, 

§  385.    Arem  Mvsculares— Arena  of  the  attachment  of  muscles. — Upon  these  two  fig- 
ures of  the  scapula  and  upon  four  views  of  the  humerus  (Fig.  68-71),  the  areas  of  muscular 


154 


ANATOMICAL    TECHNOLOG  F. 


attacliment  are  enclosed  by  interrupted  lines.  Following  tlie  method  of  Gray  (A)  and 
H.  S.  Williams  (I),  the  origins  are  indicated  by  dots  and  the  insertions  by  short  lines.  It  is 
easy  to  associate  these  two  marks  with  the  letters  o  and  i,  which  form  respectively  the 
initials  of  origin  and  insertion. 

The  scapula  affords  origin  to  the  following  10  muscles  :  8iibsmpularis,  swpraspinatus, 
infraspinatus,  medliriceps,  spina -deltoideus,   acromio-deltoideus,    teres    (major),  micoftnlis 

(teres  minor),  biceps  and  cora- 

\.\,5 ^^  coideus.     Upon  it  are  inserted 

v^Vf^  ,    .    ,  "^^  the     following     7     muscles: 

■iO      ^.^(^J^^^S^ — |T7^^^4^      ^  Acromio-trapezius,    spino-tror 

pezius,  rhomhoideus,  serratus, 
levator  anguli  scapulae,  lecator 
daviculoe  and  occipito-scapu- 
laris.  On  the  figure  the  in- 
sertion area  of  the  last  named 
muscle  is  represented  as  "too 
near  the  coraco-vertebral  an- 
gle. 

§  386.  Collvm  —  Neck.  — 
This  is  the  thickened  and 
slightly  constricted  portion  of 
the  scapula  connecting  the 
glenoid  end  or  angle  with  the 
body  of  the  bone.  According 
to  Quain  (A,  II,  83),  its  limits 
are  differently  assigned  by 
anatomists  and  surgeons. 

§387.  Foramen  Nutrieus — 
The  vascular  foramen. — There 
may  be  1,  2  or  3  of  these  fora- 
mina upon  the  ental  aspect, 
and  their  location  is  quite 
variable.  They  always  enfer 
obliquely  so  as  to  point  toward 
the  glenoid  end  of  the  bone,  and  at  least  one  of  them  is  traceable  to  the  base  of  the 
mesoscapula. 

Fossa  Glenoidea. — See  description  of  Fig.  45,  §  399. 

§  388.  Fossa  SuhscapulariH. — This  name  is  applied  to  the  entire  ental  surface  of  the 
boiie ;  as  shown  upon  the  figure,  however,  the  muscle  of  the  same  name  does  not  arise 
from  the  whole  area.  Most  of  the  margin  of  the  fossa  is  more  or  less  raised.  The  shaded 
area  represents  a  shallow  longitudinal  furrow  which  coincides  nearly  with  the  mesoscap- 
ula  (Fig.  44). 

Between  the  furrow  and  the  coracoid  margin  ars  two  well  marked  ridges  for  the  attach- 
ment of  tendinous  intersections  of  the  M.  subscapula7i,s  ;  there  are  usually  other  ridges 
which  are  most  distinct  in  old  individuals.  Near  the  glenoid  margin  is  a  prominent  ridgo 
which  separates  the  Fs.  suhscnpiilaris  proper  from  the  shallow  furrow  which  gives  origin 
to  the  31.  tere^.  The  M.  nncostalis  arises  from  the  middle  two  fifths  of  the  Mrg.  glenoi- 
devs,  and  its  glenoid  third  gives  ori<rin  to  the  M.  meditriceps. 
Meti acromion. — This  is  better  shown  in  Fig.  44  and  45. 
§  389.   Process  IS  Coracoideus—The  coracoid  process. — This,  as  better  seen  in  Fig.  45, 


1^^^''\,>*S'^^>; 


*»■' 


,U' 


Fig.  48. — ^The  Ental  Aspect  op  an  Adult  Left 
Scapula  ;   x  1. 


THE    ECTAL    ASPECT    OF    THE    SCAPULA, 


155 


^^^^ 


projects  sharply  entad  between  the  Fs.  glenoidea  and  the  Mrg.  coracoideus.    From  ita 
extremity  arises  the  M.  coracoideus  (Fig.  75). 

liidges. — See  Fs.  subscapular  is. 

Taberculum  Bicipitak.—Siee  Fig.  45. 

§  390.  Description 
of.  Fig.  44. — The  ectal 
aspect  of  the  scapula. 

The  principal  feature 
of  this  surface  is  the  sub- 
triangular  lamina  which 
projects  therefrom;  its 
direction  is  approximately 
longitudinal,  but  it  is 
more  nearly  parallel  with 
the  longer  part  of  the 
coracoid  border,  and  it 
inclines  in  the  opposite 
direction.  It  begins  as 
a  triangular  elevation  at 
the  vertebral  border  of 
the  scapula,  and  rises 
rapidly  to  about  the  mid- 
dle of  the  length  of  the 
bone,  where  its  edge  is 
thickened  and  roughened. 
From  this  point  toward 
the  glenoid  end  its  eleva- 
tion remains  nearly  uni- 
form, but  there  are  pro- 
jections which  will  be 
described  presently.  This 
ectal  ridge  is  the  mesoscapula  or  spine  of  the  scapula. 

§  391.  In  the  light  of  Embryology  and  Comparative  Anatomy,  the  entire  scapula  may- 
be regarded  as  essentially  a  subcylindrical  bar.  With  most  Mammals  the  sides  are  pro- 
duced in  three  directions  so  that  a  transection  is  irregularly  T-shaped ;  the  upright  of  the 
T  represents  the  ectal  ridge  just  described,  and  the  two  arms  of  the  cross-piece  represent 
the  two  laminae  at  right  angles  therewith  which  constitute  the  principal  part  of  the  bone, 
and  whose  borders  are  respectively  glenoid  and  coracoid.  By  Parker  (A,  215),  these  three 
regions  are  called  respectively  mesoscapula,  postscapula  and  prcescapula. 

Consistently  with  these  names,  the  glenoid  border  should  be  called  Mrg.  postscapularis, 
and  the  coracoid  Mrg.  proiscapvlaris  ;  the  fossse  between  them  and  the  mesoscapula  should 
also  be  similarly  designated.  Since,  however,  the  anthropotomical  name  for  mesoscapula 
is  spiyie,  and  in  the  natural  attitude  of  man  its  direction  is  approximately  horizontal,  these 
fossa}  have  been  named  vifraspimms  and  supraspinous,  while  the  muscles  arising  there- 
from are  called  infraspinatus  and  supraspinatus.  Until  it  shall  be  agreed  to  change  the 
names  of  these  muscles,  it  will  probably  be  more  convenient  to  retain  the  anthropotomical 
names  for  the  fossae. 

§  392.  Acromion — Pre.  acromialis — Acromion  process  (Fig.  30,  43,  46,  47). — This  forms 
the  free  extremity  of  the  mesoscapula.  Its  ectal  border  is  deflected  slightly  from  the  line 
of  the  mesoscapula  toward  the  coracoid  border.  In  man  it  articulates  witii  the  clavicle, 
but  in  the  cat  it  is  connected  therewith  by  only  a  slender  ligament  or  strip  of  fascia. 


Glenoid  angle'. 
Fig.  44. 


The  Ectal  Aspect  op  an  Adult  Left  Scap- 
ula :   X  1. 


156 


ANATOMICAL    TECHNOLOGY. 


%  393.  Delta  MeaoscapulcR — The  delta  of  the  mesoscapula  (Fig.  44). — We  suggest  this 
as  a  suitable  designation  of  the  slightly  elevated  triangular  rough  surface  at  the  vertebra] 
end  of  the  mesoscapula. 

§  394.  Fussa  Infraspinata — The  infraspinous  fossa. — This  is  the  larger  of  the  two  ectal 
fossae,  and  is  distinctly  triangular  in  shape.  It  is  overhung  by  the  mesoscapula  and 
metacromion. 

§  395.  Fossa  Supraspinata — The  supraspinous  fossa. — This  is  less  regular  in  form  than 
the  infraspinous  fossa,  and  its  area  is  less  extensive  ;  but  the  muscle  which  occupies  it  is 
larger  than  might  be  inferred,  both  on  account  of  the  inclination  of  the  mesoscapula  and 
its  own  projection  beyond  the  coracoid  border  of  the  scapula. 
Mesoscapula — Spine  of  the  scapula. — See  above  (§  390). 

§  396.  Metacromion — (Fig.  43,  67). — At  its  greatest  elevation,  near  the  glenoid  end,  the 
mesoscapula  is  produced  over  the  infraspinous  fossa  as  a  quadrate  or  subtriangular  pro- 
cess, the  metacromion.     Its  ectal  surface  and  free  border  are  rough  for  the  insertion  of  the 

MM.  levator    clamculce   and   acromio- 
A.  GUno'id    ^nd  oj  rl^ht   acapula. 
TIxlI.  LiclpLtale 
Acromion. 


MeCacromion.    ** 


PrxL  Cora  CO  icLtu.& . 
-/basa  ^lanoliUa 


Cajjut  xriituCldre 


trocUtfrtana— .CHH 

m^  Trochin 

>^H 

m\ 

^"^ 
^%^ 

'  \. 

B.    Head    o-f    V-l^kt    fiumt>ruS, 
Fig.  45. — The  Glenoid  End  op  an  Adult 
Right  Scapula  (A),  and  the  Proximal 
END  OP  AN  Adult  Right  Humerus  (B); 
slightly  reduced. 


trapezius. 

§  397.  Tuberositas  (Mesoscapulce) — 
The  tuberosity  of  the  spine  of  the 
scapula. — At  about  midway  between 
the  tip  of  the  acromion  and  the  delta 
the  mesoscapula  is  thickened  and 
roughened,  constituting  the  tuberosity/. 

§  398.  Explanation  of  Fig.  45, 
A. — This  shows  the  glenoid  end  of  a 
right  scapula.  The  bone  is  so  placed 
that  the  acromion  appears  less  pointed 
than  the  metacromion,  the  infraspi- 
nous surface  of  the  mesoscapula  is 
much  foreshortened,  and  only  a  part 
of  the  glenoid  border  is  shown ;  the 
coracoid  border  is  not  represented  at 
all. 

Between  the  acromion  and  the  ectal 
margin  of  the  Fs.  glenoidea  is  a  deep 
notch,  the  Incisura  magna  {scapular is), 
or  "  great  scapular  notch." 

§  399.  Fossa  Glenoidea — This  is 
seen  to  be  a  shallow  concavity  with  a 
pear-shaped  outline.  The  smaller  end 
forms  a  distinct  Tbcl.  {tuherculum)  bi- 
cipitale  for  the  attachment  of  the  M. 
Near  this  end,  the  ental  border  of  the 


biceps  at  the  root  of  the  Pre.  {processus)  coracoideus. 
fossa  presents  a  slight  emargination. 

§  400.  Pre.  {processus)  Coracoideus — The  coracoid  process. — This  shows  here  to  the 
best  advantage  as  a  hook-like  process  comparable  with  the  beak  of  some  birds  (whence  its 
name),  or  with  a  half-bent  finger,  as  suggested  by  Humphrey  (A,  366).  At  its  base,  oppo- 
site the  emargination  near  the  smaller  end  of  the  Fs.  glenoidea,  is  a  nutrient  foramen. 

§  401.  Explanation  of  Fig.  45,  B.— This  represents  the  proximal  end  of  a  right 
humerus,  with  the  dorsal  side  uppermost.  When,  therefore,  the  humerus  and  the  scap' 
ula  are  in  contact  at  the  shoulder,  the  upper  and  narrower  part  of  the  arthral  surface  of 
the  former  is  received  by  the  lower  and  wider  part  of  the  Fossa  glenoidea. 


THE    HUMERUS.  157 

The  general  outline  of  the  proximal  end  of  the  bone  is  approximately  that  of  an  irreg- 
ular lozenge,  the  two  smaller  angles  blunted,  and  one  of  the  sides  strongly  indented.  The 
angles  are  dorsal  and  ventral,  caudal  and  cephalic,  while  the  sides  face  obliquely  ventro- 
rephalad,  etc. 

The  following  descriptions  should  be  considered  in  connection  with  what  is  said  of  the 
parts  under  Fig.  46  : — 

§  402.  Ganalis  Biclpitalis— "The  h\c\\)\ia].  canal  or  groove  (Fig.  30,  46,  69,  70,  75).— This 
appears  as  a  notch  between  the  trochiii  and  the  trochiter,  and  is  overhung  more  by  the 
former.  Through  it  passes  the  tendon  of  the  M.  biceps  on  its  way  to  the  Tbd.  bicipitale 
of  the  scapula  (Fig.  45,  A). 

§  403.  Capnt  Articulare — The  arthral  head  or  anatomical  head  of  the  humerus  (Fig. 
30,  46,  68-71). — This  presents  a  smooth  convex  surface  which,  as  viewed  perpendicularly 
to  the  proximal  end  of  the  bone,  is  irregularly  circular  in  outline.  Really,  however,  it 
extends  upon  the  dorsal  aspect  of  the  bone,  and  is,  as  a  whole,  approximately  triangular. 
It  is  much  larger  than  the  Fs.  glenoidea  of  the  scapula  with  which  it  articulates,  being 
twice  as  lon^  and  more  than  half  as  wide  again. 

§  404.  Fossa  Trochiteriana— The  trochiterian  fossa  (Fig.  30,  68).— This  is  a  depression 
upon  the  cephalic  aspect  of  the  proximal  extremity  of  the  humerus  near  the  tip  of  the 
trochiter.     Upon  it  is  inserted  the  M.  mfraspinatus. 

§  405.  TVoc/im— The  caudal,  "  inner  "  or  "  lesser  "  tuberosity  (Fig.  3,  40,  69-73).— This 
forms  the  caudal  obtuse  angle  of  the  lozenge  represented  by  the  entire  proximal  aspect. 

Notwithstanding  the  objections  of  Hyrtl  (B,  200),  we  have  employed  the  names  epicon- 
dylus,  epitrochlea,  trochiter  and  trochin,  which  were  proposed  by  Chaussier  and  adopted  by 
Straus-Durckheim  (A,  I,  512). 

§  408.  Trochiter— The  cephalic,  "outer"  or  "greater"  tuberosity  (Fig.  30,  46,  68,  69, 
71,  67,  74). — The  proximal  border  of  this  forms  the  veutro-cephalic  side  of  the  lozenge  rep- 
resented by  the  entire  proximal  end  of  the  bone. 


THE  HUMERUS  (Fig.  6,  7,  30,  45,  46,  67-75,  105). 

References. — Straus-Durckheim,  A,  I,  511-514;  Owen,  A,  II,  511;  Humphrey,  A, 
371-377  ;  Chauveau,  A,  83,  84 ;  Chauveau  (Fleming),  A,  73.  74 ;  Flower,  A,  239,  246 ; 
Leyh,  A  ;  Gray,  A,  223-228  ;  Quain.  A,  I,  85-87. 

§  407.  General  Description. — This  is  the  single  bone  of  the 
brachium,  the  proximal  segment  of  the  arm.  According  to  the 
membral  terminology  suggested  by  Marsh  (see  §  83),  it  is  the  ce- 
phalic 0.  propodiale.  Its  proximal  and  distal  ends  form  with  the 
scapula  and  with  the  ulna  and  radius  the  shoulder  and  elbow  joints 
respectively. 

In  all  Vertebrates  excepting  the  "fishes,"  that  is,  in  all  Am- 
phibia, Reptiles,  Birds  and  Mammals,  excepting  the  armless 
Amphibia  (Csecilians)  and  Reptiles  (serpents  and  a  few  lizards),  the 
humerus  is  present  and  gives  attachment  to  numerous  and  impor- 
tant muscles.  In  the  cat,  as  partly  shown  upon  Fig.  68-71,  it  affords 
Origin  and  insertion  to  many  muscles. 


158 


ANATOMICAL   TECHNOLOGY. 


Srpohiter. 


ExtremLfas 

praximaLis^ 


The  humerus  of  the  cat  presents  a  subcylindrical  shaft — the 
diaphysls^  and  two  enlarged  and  irregular  ends— the  Extremitates 
proximales  and  distales. 

Viewed  from  the  ventral  or  dorsal  aspect,  the  caudal  and  ce- 
phalic outlines  of  the  entire 
bone  are  concave,  the  con- 
cavity being  both  greater 
and  more  regular  on  the  cau- 
dal side  (on  which  the  three 
braces  are  placed).  Seen, 
however,  from  either  the  cau- 
dal or  cephalic  side,  as  in 
Fig.  68  and  70,  the  dorsal 
and  ventral  outlines  are 
S-shaped.  On  the  dorsal 
side  the  sharper  curvature 
is  near  the  distal  end,  while 
the  reverse  is  the  case  with 
the  ventral  side.  In  other 
words,  the  proximal  extrem- 
ity is  more  enlarged  dorsad, 
and  the  distal  one  v en- 
trad. 

The  cat's  humerus  does 
not  present  the  appearance 
of  having  been  twisted  which 
characterizes  that  of  man 
and  some  other  Mammals — 
an  appearance  which  is  due, 
at  least  in  part,  to  the  devel- 
opment of  ridges  with  inter- 
vening   furrows    having    a 


^a-pLthlumi 


Fig.  46. — The  Ventral  (Anterior)   Aspect 
OP  AN  Adult  Right  Humerus  :    x  1. 


more  or  less  distinctly  spiral  arrangement  for  the  attachment  or 
accommodation  of  muscles,  vessels  or  nerves. 

§  408.    Description  of  Fig.  46.— This  represents   ttie  ventral  aspect   of  the  right  ^ 
humerus,  that  Avhich  is  most  commonly  and  fully  examined  and  compared.    The  same  aspect 
of  the  left  humerus  is  represented  in  Fig.  69,  and  the  cephalic,  caudal  and  dorsal  aspects 
in  Fig.  68, 70  and  71  respectively. 

§  409.  Canalis  Bicipitalis—The  bicipital  canal  or  groove  (Fig.  30,  45,  46,  69,  70).— 
This  is  a  marked  depression  upon  the  ventro-caudal  aspect  of  the  proximal  extremity.  As 
better  shown  in  Fig.  45,  it  lies  between  the  eminences  called  trochiter  and  troehin.     In  the 


TBE    HUMERUS.  159 

fresh  state  it  is  converted  into  a  foramen  or  closed  canal  by  tendons  wliicb  are  inserted 
upon  these  parts.  Through  it  plays  the  tendon  of  the  M.  biceps,  the  one  which  represents 
the  "  long"  or  "  glenoid  "  head  of  the  muscle  in  man.  By  Straus-Durckheim  (A.  I,  512), 
the  canal  is  called  "  coulisse  bicipitale." 

§  410.  Capitellum  {humeri) — I'he  radial  head,  external  or  outer  condyle  (Fig.  30,  46,  6). 
— The  distal  end  of  the  bone  presents  a  smooth  saddle-shaped  surface,  the  caudal  border 
of  which  is  raised,  and  the  cephalic  border  rounded.  As  seen  from  the  ventral  aspect,  this 
arthral  surface  is  nearly  equally  divided  by  a  slight  ridge,  and  the  convex  cephalic  part 
is  the  capitellum.  This  surface  narrows  as  it  is  continued  over  the  distal  end  of  the  bone, 
so  that  its  shape,  if  extended  in  a  plane,  would  be  approximately  lanceolate  or  pear-shaped, 
with  a  distinct  eraargination  at  the  cephalic  side  of  the  base. 

With  the  capitellum  articulates  the  fossa  at  the  proximal  end  of  the  radius  ;  this  end, 
unfortunately,  being  likewise  named  capitellum.  It  would  be  well  if  anatomists  could 
agree  to  call  one  of  these  parts  capitellum  and  the  other  capitulum. 

§  411.  Caput  {humeri)  Articulare — The  artliral  or  anatomical  head  of  the  humerus. — 
The  smooth  convex  aithral  surface  of  this  part  hardly  appears  in  this  view  of  the  bone, 
but  is  shown  in  Fig.  71.  In  man  it  is  distinguished  from  the  non-arthral  surlace  of  the 
rest  of  the  Ext.  proximayis  by  a  furrow  or  constriction,  the  anatomical  neck.  In  the  cat, 
this  neck  is  not  clearly  defined. 

§  413.  Crista  Deltoldea — The  deltoid  ridge — "  Crete  deltoidienne  externe,"  Straus- 
Durckheim  (A,  I,  518)— (Fig.  46,  68,  69). — This  is  a  narrow,  nearly  straight,  and— in  well 
marked  adult  humeri — sharply  defined  raised  line  extending  from  the  tubercle  for  the 
insertion  of  the  M.  micosialis  {F\g.  69)  at  the  base  of  the  trochiter  on  the  cephalic  aspect 
of  the  proximal  extremity  distad  and  ventrad,  to  lose  itself  on  the  third  fourth  of  the  ven- 
tral border.  The  sharpness  which  characterizes  its  proximal  portion  disappears  at  about 
the  middle  of  the  bone. 

§  413.  Crista  Pectoralis— The  pectoral  ridge — "  Crete  deltoi'diennc  anterieure,"  Straus- 
Durckheim — (Fig.  46,  69). — This  name  is  applied  by  us  to  the  ill  defined  rough  hne  upon 
the  proximal  two  thirds  of  the  ventral  aspect  of  the  humerus. 

This  and  the  Crs.  deltoidea  converge  distad,  but  cease  to  be  distinct  before  meeting. 
The  long  triangular  interval  between  them  is  called  by  Straus-Durckheim  (A,  I.,  513), 
"  empriente  deltoidienne."  Mivart  applies  (B,  93,  Fig.  53),  the  name  deltoid  ridge  to  vv^hat 
seems  to  correspond  to  this  interval,  and  inaccurately  states  that  the  two  parts  of  the 
M.  deltoideus  above  mentioned  are  inserted  upon  it. 

§  414.  Diap/iysis— The  shaft  (Fig.  46,  30,  68-71).— Although  the  shaft  of  the  humerus 
may  be  generally  described  as  approximately  cylindrical,  it  is  slightly  compressed,  so  that 
at  any  point  its  cephalo-caudal  diameter  is  less  than  its  dorso-ventral.  It  is  slightly 
curved  so  as  to  present  a  ventral  convexity. 

For  convenience  of  description,  the  entire  bone  may  be  said  to  consist  of  a  subcylindrical 
shaft  and  enlarged  extremities.  Strictly  speaking,  however,  the  diaphysia  includes  all 
but  the  proximal  and  distal  epiphyses,  and  these  are  less  extensive  than  the  regions  desig- 
nated as  extremitates.  In  a  young  animal  the  proximal  epiphysis  separates  along  an 
undulating  line  passing  distad  of  the  caput  articulare  and  the  tubercle  for  the  insertion  of 
the  M.  micostfdis.  The  greatest  length  of  the  epiphysis  equals  only  about  one  eighth  of 
the  length  of  the  entire  humerus,  whereas  the  Ext.proximalis  includes  about  one  fifth.  The 
distal  epiphysis  also  includes  merely  so  much  as  bears  the  arthral  surfaces  witli  the  epi- 
trochlea  and  epicondylus,  whereas  the  proximal  limit  of  the  Ext.  distalis  embraces  also  the 
Fm.  epitrochlcare. 

Upon  the  caudal  aspect  of  the  diaphysis,  near  the  junction  of  the  first  and  second 
fourths,  and  nearer  the  ventral  than  the  dorsal  border,  is  to  be  seen,  with  adult  humeri,  a 


160  ANATOMICAL    TECHNOLOGY. 

narrow  longitudinal  depression  roughened  for  the  attachment  of  the  conjoined  tendons  of 
the  MM.  teres  (major)  and  latissimus  (dorsi).  It  is  indicated  by  an  interrupted  line  on 
Fior.  70.  On  Fig.  46  it  does  not  appear,  but  its  proximal  end  would  be  opposite  the  proxi- 
mal end  of  the  longer  brace.  Its  length  equals  the  dorso-ventral  diameter  of  the  bone 
opposite  its  distal  end. 

§  415.  Epicondylus—ThQ  epicondyle  or  external  condyle  (Fig,  30,  46,  68,  69,  71,  74).— 
This  is  a  rough  subconical  eminence  upon  the  cephalic  aspect  of  the  distal  extremity.  To 
it  is  attached  the  proximal  end  of  the  cephalic  (external)  lateral  ligament  of  the  elbow, 
and  from  it  arise  the  MM.  Extensor  ulnaris  and  Ext.  minimi.  Obliquely  proximad  from 
the  epicondylus  extends  the  Crista  epicondylaris,  which  loses  itself  on  the  dorsal  aspect  of 
the  diaphysis  nearly  opposite  the  point  of  nearest  approximation  of  the  deltoid  and  pectoral 
crests  upon  the  ventral  aspect. 

The  epicondyle  has  been  called  "outer"  or  "external  condyle,"  and  more  recently 
by  Markoe  {!)  and  others  "  external  epicondyle." 

§  416.  Epitrochlea— The  epitrochlea  or  internal  condyle  (Fig.  30,  46,  69,  70,  71,  75).— 
This  is  is  a  rough  subconical  eminence  upon  the  caudal  aspect  of  the  distal  extremity.  It 
is  larger  than  the  epicondylus,  and  springs  abruptly  from  the  nearly  plane  caudal  surface 
formed  by  the  caudal  prominence  of  the  trochlea.  Proximad,  however,  it  is  directly  con- 
tinuous with  the  bar  forming  the  caudal  boundary  of  the  Em.  epitrochleare. 

§  417.  Fm.  {Foramen)  Epitrochleare— Hhe  epitrochlear  or  supracondyloid  foramen 
(Fig.  30,  46,  69,  70,  75,  105). — This  is  a  narrow  perforation  from  the  ventral  to  the  dorsal 
aspect  of  the  humerus  near  the  caudal  side  of  the  distal  extremity.  Through  it  pass  the 
N.  medius  and  the  A.  brachialis  on  their  way  from  the  dorso-caudal  to  the  ventral  aspect 
of  the  arm. 

In  the  cat,  the  Fm.  epitrochleare  is  within  the  naturally  assigned  limits  of  the  Ext. 
distalis,  but  it  is  wholly  within  the  diaphysis  ;  its  distal  boundary  is  sometimes  very  near 
the  diaphysio-epiphysial  suture,  and  sometimes  separated  therefrom  by  a  space  equal  to 
the  longer  diameter  of  the  orifice. 

The  Fm.  epitrochleare  exists  in  the  other  Felidae  and  in  some  other  Carnivora  (Flower, 
A,  246),  and  occasionally — partly  circumscribed  by  ligament — in  man  (Humphrey,  A,  373 ; 
Quain,  A,  I,  87).  Usually,  however,  the  human  humerus  presents  merely  an  emargination 
of  the  bone,  along  which  pass  the  median  nerve  and  the  brachial  artery. 

§  418.  Fossa  Radialis  and  Fs.  IFlnaris— The  radial  and  ulnar  fossae  of  the  humerus 
(Fig.  46). — On  the  ventral  (anterior)  aspect  of  the  distal  extremity  of  the  humerus,  just 
proximad  of  the  arthral  surfaces  of  the  trochlea  and  capitellum,  are  two  slight  depressions, 
against  which,  in  the  strongly  flexed  condition  of  tlte  elbow,  abut  the  coronoid  process  of 
the  ulna  (Fig.  30,  Pre.  coronoideus),  and  the  side  of  the  capitellum  or  proximal  arthral  end 
of  the  radius  (Fig.  30) ;  hence  their  respective  names.  Between  the  two  fossae,  especially 
in  well  marked  bones,  is  a  slight  ridge.  The  Fossa  ulnaris  is  described,  but  not  named, 
by  Straus-Durckheim  (A,  I. ,  513). 

§  419.  The  Fossa  olecranalis,  on  the  dorsal  aspect  of  the  distal  extremity,  will  be 
described  in  connection  with  Fig,  71, 

§  420.  Trochin  and  Trochiter— The  caudal  (lesser  or  inner)  and  the  cephalic  (greater 
or  outer)  humeral  tuberosities  (Fig.  30,  45,  68-71).— These  parts  of  the  proximal  extremity 
have  been  described  in  connection  with  Fig.  45,  and  their  muscular  attachments  will  be 
mentioned  in  connection  with  Fig.  68-71,  See  also  above,  Canalis  hicipitalis.  It  has  been 
mentioned  under  Fig.  45  that  while  the  trochin  is  v/holly  caudal  in  position,  the  trochiter 
is  about  equally  ventral  and  cephalic. 

Trochlea— (^\g.  46,  69,  71).— This  is  the  half  saddle  shaped  arthral  surface  at  the 
caudal  side  of  the  distal  end  of  the  humerus.     Its  caudal  border  is  raised  and  sharply 


THE    CARP  ALIA. 


161 


rlefined,  but  ceplialad  it  is  continuous  with  the  capitellum,  the  limits  of  the  two  surfaces 
being  indicated  by  a  slight  ridge.  Ventrad,  the  two  surfaces  are  nearly  equal  in  extent, 
but  dorsad  the  capitellum  gradually  narrows  and  disappears  as  seen  in  Fig.  71,  while 
the  trochlea  continues  upon  the  dorsal  aspect  of  the  bone  and  has  a  decidedly  oblique 
direction. 


THE  CARPALIA  (Fig.  6,  30,  47). 
The  bones  of  the  carpus  (wrist)  have  been  enumerated  in  §  84. 

References. — In  addition  to  the  references  given  in  §§  84,  85,  see  Gegenbaur,  B  ; 
Straus-Durckheim,  A,  I,  518-524 ;  Mivart,  B,  96-98  ;  Gray,  A,  235-241 ;  Quain,  A,  I, 
90-93,  99  ;  C^hauveau,  A,  88,  89  ;  Chauveau  (Fleming),  A,  78,  80  ;  Leyh,  A,  177-182  ; 
Flower,  A,  252-2G0  ;  Humphrey,  A,  387-390. 

§  421.  Explanation  of  Fig.  47. — This  represents  the  dorsal  aspect  of  the  carpus  and 
of  the  contiguous  parts  of  the 

metacarpalia   of   an"    Asiatic  ^         y       sc  ^,,^  ^*-^_A 

lion  seven  months  old,  and  n 
of  two  young  dogs.  The  let- 
tering is  nearly  uniform  in 
the  three  figures,  but  the 
present  description  refers 
only  to  the  lion. 

P,  I,  M,  A,  Mi,  the  meta- 
carpalia of  the  poUex,  in- 
dex, medius,  annularis  and 
minimus ;  p,  the  0.  pisi- 
forme,  which  is  really  a  sesa- 
moid hone  in  the  tendon  of 
the  M,  flexor  ulnaris,  and 
not  a  true  carpal  element ; 
w,  m,  td  and  tm,  the  UTici- 
forme^  magnum^  trapezoid 
and  trapezium  respectively, 
forming   the  distal   row   of 

carpalia  ;  as  stated  in  §  84,  the  unciforme  is  supposed  to  represent  two  elements  of  the 
typical  or  primitive  carpus. 

The  proximal  row  consists  of  but  two  cartilaginous  pieces,  commonly  known  as  the 
evneiforme  (py)  and  the  scapJio-lunare.  Since  cww^i/brmg  has  become  well  established  in 
the  names  of  three  of  the  tarsal  bones,  we  have,  upon  the  suggestion  of  Prof.  O.  C.  Marsh 
and  in  accordance  with  the  custom  of  some  European  anatomists,  substituted  therefor  the 
term  pyrnmidale,  which  was  employed  by  Straus-Durckheim  (A,  I.,  520),  This  element 
represents  the  ulnare  of  the  primitive  carpus. 

The  larger  proximal  piece  is  a  single  mass  of  cartilage,  but  a  section  shows  that  ossifi- 
cation has  b3gun  from  three  separate  centers.  The  two  larger  correspond  to  the  scaphoides 
{sc)  and  the  hinare  (l)  of  man,  and  to  the  radiale  and  intermedium  of  the  primitive  carpus. 
The  third  and  smaller  center  {ce)  probably  represents  the  centrale  of  the  primitive  carpus, 
which  is  not  distinct  in  man. 

So  far  as  appears  from  the  figure  of  Mivart  (B,  Fig.  60),  the  carpus  of  the  cat  is  essen- 
tially similar  to  that  of  the  lion. 
11 


Fig.  47. — The  Dorsal  Aspect  op  the  Carpal  Region 
OP  A  Young  Lion  (largest  figure)  and  op  Two 
(From  Wilder,  19,  301,  Fig.  1.) 


Young  Dogs. 


162  ANATOMICAL    TECHNOLOOT, 

CLAVICULA  (Fig.  30,  48,  66,  67,  72). 

The  clavicle  or  collar  bone  is  briefly  descril^d  in  §  213. 

References.— Straus-Durcklieim,  A,  I,  509  ;  Flower,  A,  328;  Gegenbaur  (Lankester), 
A.  477  ;  Gegenbaur,  C  ;  Gray,  A,  215-318  ;  Quain,  A,  I,  84,  96 ;  Parker,  A.  215  ;  Hum- 
plirey,  A,  359-363. 

§  423-  Explanation  of  Fig.  48. — This  represents  the  unusually  large  and  well 
marked  clavicles  or  collar  bones  of  an  old  male  cat.  Their  mesal  or  sternal  ends  are 
apposed,  and  are  seen  to  be  approximately  cylindrical. 

The  left  is  placed   in  nearly  its  natural 

.   .  -  TnwoL  j^       attitude  in  the  body,  showing  that  its  cephalo- 

cai^g^^^^^^^^  ^^i^^':—-^^^        caudal  diameter  is  nearly  uniiorm,  and  that 

lafeif^i^^^'^^  ^^^^^"tt^etnL     ®^*^^  ®"^  curves  slightly  caudad,  the  mesal 

Fig.  48.-THE  Right  and  Le^  Cla-      ^^^  '^'^  ™^^^  decidedly. 

VIOULiB  OF  AN  OlD  CaT  ;    X  1.  '^^^    "S^^*   ^«    «^    P^*^^^    *«    ^«    ^^^^'^    ^^'^ 

caudal  aspect,  and  display  the  dorsal  concav- 
ity. The  mesal  half  is  nearly  straight,  but  the  lateral  is  quite  regularly  curved.  The 
dorso-ventral  diameter  of  the  bone  increases  gradually  toward  the  lateral  end,  which  is 
about  twice  the  width  of  the  mesal. 

Directly  or  indirectly,  the  clavicle  affords  attachment  to  the  Mm.  clavo-trapezins,  clavo- 
mastoideus  and  claco-deltoideus,  but  as  it  is  connected  with  the  sternum  and  the  scapula 
only  by  ligaments,  it  is  moved  with  the  muscles  instead  of  forming  an  efficient  fulcrum 
for  their  action. 

THE  STERNUM  (Fig.  7,  30,  50,  73,  73,  99,  100). 

The  sternum  or  breast  bone  was  briefly  described  in  §  210. 

References.— Straus-Durckheim,  A,  I,  496,  497 ;  Mivart,  B,  49,  50  ;  Flower,  A,  73  : 
Humphrey,  A,  321-329  ;  Gray,  A,  207-210  ;  Quain,  A,  I,  25-27  ;  Chauveau,  A,  75;  Chau- 
veau  (Fleming),  A,  66  ;  Leyh,  A,  164-166  ;  Parker,  A,  215. 

§  423.  Explanation  of  Fig.  49. — The  ventral  aspect  of  an  adult  sternum,  with  the 
contiguous  parts  of  the  costicartilagines.  Incomplete  views  of  the  sternum  are  given  in 
Fig.  30,  50,  72,  73,  99  and  100. 

The  sternum  consists  of  a  mesal  series  of  osseous  or  partly  cartilaginous  segments 
called  sternebrcB,  united  by  cartilages.  The  figure  was  drawn  from  a  dried  sternum,  and 
the  intersternebral  cartilages  are  not  shown  distinctly,  neither  is  indicated  the  line  of  junc- 
tion of  the  osseous  and  cartilaginous  portions  of  the  caudal  segment. 

Of  the  sternebrae,  the  most  cephalic  and  the  most  caudal  have  received  special  names, 
presternum  and  xipMsternum.     The  intervening  segments  constitute  the  mesosternum. 

§  424    Mesosternum. — As  indicated  in  i^  310,  there  may  be  cither  6  or  7  mesosternebrse, 
making  the  total  number  ofrsternebrae  8  or  9.     The  variation  is  due  to  the  presence  or 
absence  of  a  short  and  nearlyi cubical  piece  between  the  xiphisternum  and  the  sixth  con- 
stant megosterneber.     This  piece  is  neither  figured  nor  described  by  Mivart  (B,  Fig.  24), 
or  Parlier  (A,  PI.  xxx.  Fig.  3),  and  does  not  appear  distinctly  in  the  figures  of  Straus 
Durckheim  (A,  PI.  vi,  Fig.  2,  and  PI.  vii.  Fig.  3),  notwithstanding  his  intimation  (A,  I,546j 
that  it  is  always  present.     In  the  sterna  examined  by  us  this  seventh  piece  is  sometime 
quite  largo,  and  in  other  cases  so  small  as  to  be  unrecognizable,  at  least  from  the  surface^ 
We  have  also  observed  considerable  diversity  as  to  the  number  of  costicartilagines  whicl 
reach  the  sternum,  but  are  not  yet  prepared  to  say  whether  8  or  9  is  the  more  frequent 


THE    STERNUM. 


163 


nnmbQr.     The  costicartilages  which  reach  the  sternum  articulate  therewith  diaTthrodially^ 
but  thoi'o  is  considerable  diversity  as  to  the  extent  of  the  synovial  capsules. 

Each  of  the  constant  mescsteruebrae  is  two  or  three  times  as  long 
as  wide,  and  slightly  enlarged  at  the  ends  so  as  to  be  somewhat  of  a  Tif^^StM-FJlum 

dumb-bell  shape, 

§  425.  PrcEsternum. — This  is  sometimes  called  manicbrium  from 
its  form  in  man.  It  is  nearly  twice  as  long  as  the  average  mesoster- 
neber,  and  the  cephalic  half,  which  is  cartilage  in  the  kitten,  is  com- 
prcissad  and  tapers  to  a  blunt  point.  On  each  side  is  an  oblique 
slioalder  for  the  attachment  of  the  first  costicartilage,  so  that  the 
entire  praesternum  is  shaped  somewhat  like  tlie  head  of  a  lance.  Its 
ventral  aspect  is  prominent  on  the  meson,  forming  the  presternal  keel. 

§  426.  Xlphisternum. — This  is  also  called  the  xiphoid  or  endform 
cartilage.  In  the  adult  cat  only  the'caudal  third  or  fourth  is  cartilage, 
and  its  tip  is  enlarged  into  a  disk.  The  rest  of  the  xlphisternum 
tapers  caudad  from  its  base. 

The  sternum  affords  attachment  to  the  MM.  ectopcctorrilis,  entopec- 
torali^i,  sterno-mastMdeu.%  sterno-hyoideMs  and  some  others. 

§  427.  Belatian  of  the  Siernehrm  to  the  Costkartildgines. — While 
dissecting,  it  is  often  desirable  to  designate  the  number  of  a  sterneber 
when  the  sternum  is  so  covered  by  muscles  as  to  make  the  enumera- 
tion difficult.  In  these  cases  the  ribs  or  their  cartilages  may  usually 
be  counted  from  the  most  cephalic  of  the  series,  their  relations  to  the 
sternebrse  being  as  follows  : — 

With  the  six  constant  mesosternebrse,  the  cartilages  are  attached 
at  the  cephalic  end,  so  that  the  third  mesosterneber,  for  example, 
which  is  the  fourth  sterneber,  would  be  the  segment  just  caudad  of 
the  |X)int  of  attachment  of  the  fourth  cartilage.  The  first  cartilages 
are  connected  with  the  sides  of  the  prtesternum,  which  is  really  the 
first  sterneber ;  the  relations  of  the  eighth  and  ninth  cartilages  are 
less  definite  and  constant. 


COST.^  (RIBS)  AND  C9STICARTILAGINES  (COSTAL    CARTI- 
LAGES).   Fig.  SO. 


References. — Straus-Durckheim,  A,  I,  493,  and  II,  57  ;  Quain, 
A,  I,  27,  141  ;  Gray,  A,  210,  295  ;  Flower.  A,  85  ;  Chauveau  (Fleming), 
A,  67.  140  ;  (^lauveau,  A  ;  Leyh,  A,  162,  9m  ;  Humphrey,  A,  329-337 ;  WoiH 

Fig.  49. — The  Ven- 


Mivart,  B,  50-52. 


,T    .^^     mi  .  .-.         ^^  T      -,  .  1        TRAL  Aspect  OF 

^  438.   The  costse  or  ribs— 13,  rarely  14,  on  each     ^n  adult  Steb- 

side— constitute  a  series  of  arched,  highly  elastic      num;  xi. 

bones  which,  with  their  continuations,  the  costicar- 

tilagines,  the  sternum  and  the  thoracic  vertebrse^  form  the  conical 

skeleton  or  framework  of  the  thorax  (Fig.  30  and  50). 

The  ribs  and  their  cartilages  are  slender  and  subcylindrical  in 

form.    They  present,  in  expiration  and  moderate  inspiration,  a  com- 

j)ound  curve,  the  convexities  being  caudal  and  lateral  (Fig.  30  and 


164  AJVATOMICAL    TECHNOLOGY. 

50).  The  ribs  proper  have  each  a  general  caudal  inclination  from 
the  tuberculum  to  the  arthron  costicartilaginis,  while  the  carti- 
lage has  a  cephalic  inclination  from  the  arthron  to  the  sternal  end 
(Fig.  30).  In  full  inspiration  the  ventral  or  sternal  ends  of  the  ribs 
are  nearly  ventrad  of  the  vertebral  ends,  the  caudal  convexity  being 
partly  or  entirely  obliterated  (Fig.  50). 

§  429.  Special  Characters. — The  capitellum  of  the  12th  and 
13th  ribs — 14th  if  present — ^articulates  with  but  a  single  vertebra. 

The  capitellum  of  the  first  articulates  to  a  slight  extent  with  the 
body  of  the  last  cervical,  but  the  diarthrodial  part  of  the  articula- 
tion is  entirely  confined  to  the  body  of  the  first  thoracic  (Flower, 
A,  23).  The  first  rib  and  those  last  named  above  (12,  18, 14),  pos- 
sess no  Ugamentum  inter  articular  e  (Fig.  50). 

The  12th  and  13th  ribs— 14th  if  present— possess  no  arthral 
tuberculum  ;  it  is  also  sometimes  absent  from  the,  11th.  The  tuber- 
culum of  each  of  the  others  articulates  diarthrodially  with  the 
diapophysis  of  the  corresponding  thoracic  vertebra ;  thus,  the 
tuberculum  of  the  first  articulates  with  the  diapophysis  of  the 
first  vertebra,  and  that  of  the  seventh  with  the  diapophysis  of  the 
seventh,  etc. 

§  430.  Sternal,  Asternal  and  Floating  Ribs. — The  cartilages  of 
the  first  nine  ribs  (Fig.  49) — rarely  of  only  the  first  eight — are  articu- 
lated with  the  sternum,  and  hence  are  called  sternal  or  true  ribs.  The 
remaining  three  (or  four)  are  called  asternal  or  false  ribs,  as  their 
cartilages  do  not  reach  the  sternum.  Finally  the  13th — 14th  if  pres- 
ent— is  not  attached  to  the  one  just  cephalad  of  it  by  connective 
tissue,  as  are  the  10th,  11th  and  12th,  but  ends  independently  in 
the  abdominal  muscles,  and  hence  is  called  a  floating  or  vertebral 
rib.     (Humphrey,  A,  329,  337  ;  Hutchinson,  A,  1016. 

§  431.  Methods  of  Demonstration. — The  form  and  the  various 
parts  of  the  ribs  are  best  made  out  in  those  that  have  been  com- 
pletely deprived  of  their  soft  parts  as  directed  above  (§  248).  The 
relations  and  mobility  of  the  ribs  singly  and  collectively,  and  their 
arthra  and  ligaments,  must  be  studied  on  fresh  or  alcoholic  speci- 
mens. 

§  432.  Elasticity  and  Mobility.— Take  as  lean  a  cat  as  possi- 
ble, place  it  dorsicumbent,  and,  commencing  at  the  ventrimeson, 
remove  the  skin  and  muscles  covering  the  sternum,  and  the  ribs 
with  their  cartilages  of  one  side.  Press  upon  the  thorax,  and  the 
elasticity  of  the  ribs  will  be  felt.     Grasp  the  second  mesosterneber 


COST^    AND    COSTICARTILAGINES.  1G5 

and  pull  ventro-cephalad.  This  will  show  the  way  in  which  the 
capacity  of  the  thorax  is  increased. 

§  433.  Arthra — Joints. — Remove  the  muscles  covering  the  tu- 
berculum  and  cervix  of  the  seventh  rib  for  example,  and  the  ligor 
ments  will  be  seen  as  white  bands  holding  the  tuberculum  to  the 
diapophysis  and  the  capitellum  in  the  socket  formed  by  the  demi- 
facets  of  the  two  vertebrae  (Fig.  52,  Arthron  capitelli).  Cut  away  the 
ligaments  on  the  caudal  side  of  the  tuberculum  with  the  arthrotome 
and  bend  the  rib  cephalad.  This  will  expose  the  smooth  arthral 
surface  of  this  diarthrodial  joint.  That  of  the  capitellum  may  be 
demonstrated  in  the  same  way. 

To  demonstrate  the  ampJiiartJirodial  joints  at  the  arthron  costi- 
cartilaginis,  the  finger  or  some  solid  substance  should  be  placed 
en  tad  of  the  arthron,  and  then  the  ectal  surface  of  the  bone  and  car- 
tilage should  be  sliced  away  with  the  arthrotome.  The  cartilage 
and  bone  will  be  found  continuous,  the  ends  not  being  separate 
and  smooth  for  gliding  upon  each  other  as  with  the  capitellum 
and  tuberculum.  The  end  of  the  rib  is  but  very  slightly  hollowed 
out  to  receive  the  cartilage,  thus  differing  from  the  condition  in 
man,  where  the  cartilage  is  implanted  in  a  deep  pit. 

The  diarthrodial  joints  of  all  the  sternal  ribs  (8  or  9)  at  the  junc- 
tion of  the  costal  cartilages  and  sternum  (§§  424,  430),  may  be  dem- 
onstrated by  slicing  off  the  ectal  surface  of  the  conjoined  sternum 
and  cartilage  as  directed  for  the  Arthron  costicartilaginis. 

§  434.  Ligamentum  interarticulare — Interarticular  ligament 
(Fig.  50). — This  is  most  satisfactorily  demonstrated  in  one  of  the 
middle  ribs,  the  seventh  for  example.  The  muscles  should  be  re- 
moved as  for  demonstrating  the  tubercular  and  capitellar  joints, 
and  the  ligaments  binding  the  tuberculum  to  the  diapophysis  should 
be  cut.  Nip  away  the  neural  arch  (Fig.  53)  and  remove  the  short 
segment  of  exposed  myelon.  This  will  expose  the  floor  of  the  neu- 
ral canal.  Dissect  the  dorsal  (posterior)  common  ligament  from  the 
intervertebral  fibro-cartilage,  move  the  rib,  and  the  Ugamenium 
interarticulare  will  be  seen,  as  a  rope  in  a  pulley,  passing  across 
the  floor  of  the  neural  canal  in  a  groove  on  the  dorsal  surface  of  the 
intervertebral  fibro-cartilage,  and  connecting  the  heads  of  the  pair 
of  ribs  (§444). 

B    §  435.  This  ligament  differs  so  remarkably  from  its  homologue  in  man  tliat  a  brief  com- 
parison is  added : — 

In  man  the  ligament  is  plate-like.     In  the  cat  it  is  thick  and  band-like.     In  man  it 


166 


ANATOMICAL    TECHNOLOGY, 


completely  divides  the  artliral  surface  of  the  capitellum  into  two  parts  corresponding  to 
the  demifacets  of  the  two  vertebrae  (Fig-.  52,  Arthron  capitelll).  In  the  cat  it  but  partially 
divides  the  surface.  In  man  the  ligament  joins  the  intervertebral  fibro- cartilage,  and  does 
not  extend  from  side  to  side.  In  the  cat  it  passes  from  side  to  side  in  a  synovial  groove 
lined  by  an  extension  of  the  synovial  membrane  lining  the  joints  of  the  capltella  of  the 
pair  of  ribs.  Hence,  while  in  man  there  SlXQ  four  separate  synovial  cavities  for  the  capitella 
of  each  pair  of  ribs  possessing  the  interarticular  ligament,  in  the  cut  there  is  but  one,  since 
the  arthra  of  the  capitella  communicate  with  each  other  through  the  groove  for  the  Liga- 
mentum  interarticulare. 

References.— Bichat,  A,  I,  231 ;   Mayer,  47,  273  ;  Chauveau,  A,  140  ;  Leyh,  A,  210 ; 
aeland,  4  and  5  ;  Quain,  A,  I,  141 ;  Gray,  A,  296  ;  Gage,  5,  421. 

§  436.    Preparation. — Fig.  50  represents  two  costse  and  costi- 
cartilagines  separated  from  the  body  and  in  the  position  assumed 

during  the  fullest  possible 
^^^^^^T.iifQrciLluM.  inspiration — that  is,  drawn 
ventrad,  laterad  and  ceplia- 
lad  so  as  to  obliterate  their 
caudal  convexity  (Fig.  30), 
and  give  the  greatest  capa- 
city to  the  thorax.  Tlie 
cleaning  process  was  carried 
only  sufficiently  far  to  re- 
move the  soft  parts,  leaving 
the  interarticular  ligament 
and  the  connections  of  the 
costal  cartilages  and  ster- 
num (§§  252,  427). 

§  487.  Arthron  ccsticartilagi- 
nis. — The  amj)hiarthrodial  articuia- 
tion  between  the  sternal  end  of  the 
diaphysis  and  its  cartilage  (§  433). 

§  438.    Arthron     mesosternebri 
—  Costo-sternal     articulation.  —  The 
diarthrodial  articulation  of  the  costal 
cartilage  with  themesosternum.    The 
first  costal  cartilage  articulates  with  a 
single    sterneber    (prsesternum),    the 
other  eight  with  two  (§  430,  Fig.  49). 
§   439.    Capitellum— Head.— The 
vertebral  end  of  the  rib  ends  in  a  somewhat  pear-shaped  capitellum  or  head  which  articu- 
lates diarthrodially  with  the  demifacets  of  two  contiguous  vertebrae  (Fig.  52,  Arthron 
capitelli.) 

%  440.    Cervix— Neck. — The  cervix  or  neck  of  the  rib  is  the  somewhat  constricted 
part  immediately  following  the  capitellum  and  between  it  and  the  tuberculum. 


Fig.  50. — Caudal  View  of  the  Seventh  Pair 
OF  CosT^  (Ribs);    xl. 


PELVIS.  167 

§  441.  Costa — Rib. — The  costa  or  rib  proper  is  tbe  bony  part  of  the  arcli  extend- 
ing from  the  capitellum  to  the  Arthrou  costicartilaginis.  It  has  two  extremities — 
vertebral  or  dorsal  and  sternal  or  ventral  ;  two  surfaces — ectal  and  ental  -  two  edges — 
cephalic  and  caudal.  The  vertebral  end  bears  the  capitellum :  the  ectal  surface  is  next 
the  skin  ;  the  cephalic  edge  faces  toward  the  head. 

§  442.  Costicartilago — Costal  cartilage.— The  cartilaginous  continuation  of  the  rib 
which  passes  from  the  sternal  end  of  the  diaphysls  toward  the  sternum  (§  423,  Fig,  49).  In 
the  figure  it  is  deeply  shaded  and  is  between  the  Arthron  costicartilaginis  and  the  meso- 
eterneher. 

§  443.  Diaphysis  (Costae)— Shaft. — The  diaphysis  of  the  rib  is  the  part  between  the 
tuberculum  and  the  Aithron  costicartilaginis. 

§  444.  Ligamentum  interarticulare,  az, — Interarticular  ligament. — This  is  a  strong, 
smooth,  band  like  ligament  connecting,  through  the  floor  of  the  neural  canal,  the  heads 
of  opposite  ribs  (2d  to  11th  pairs  inclusive) ;  (§  434). 

§  445.  Mesosternebra,  az. — The  square  area  between  the  sternal  ends  of  the  costal 
cartilages  represents  the  caudal  end  of  the  0th  mesosterneber  (§  424,  Fig.  49). 

§  44G.  Tuberculum — Tubercle. — The  tuberculum  is  an  elevation  on  the  ectal  surface 
of  the  rib  just  at  the  end  of  the  cervix.  It  bears  a  smooth  arthral  facet  which  articulates 
idiarthrodially)  with  the  diapophysis  of  the  7th  thoracic  vertebra  (Fig.  53  and  §  433). 

PELVIS. 

General  References  to  the  Pelvis.— Straus-Durckheim,  A,  I,  499,  and  II,  63  ;  Quain, 
A,  I,  100, 1.^2,  159  ;  Gray,  A,  245  ;  Cliauveau  (Fleming),  A,  91,161  ;  Chauveau,  A,  75,  153  ; 
Leyh,  A,  1G6,  312 ;  Flower,  A,  281  and  33  ;  Humphrey,  A,  438  ;  Joulin,  1  ;  Mivart,  8 
and  ID  ;  Wilder,  lO.     A  chronological  bibliography  is  given  at  the  end  of  the  ]ast. 

§  447.  Preparation. — The  soft  parts  were  fully  removed  bj  one 
of  the  processes  already  described  (§§  244-256).  Parts  of  the  first 
and  second  sacral  vertebrae  were  removed  with  nippers  to  expose  the 
Artliron  illo-sacrale.  To  show  the  lines  of  junction  between  the 
ilium,  ischium,  Os  pubis  and  Os  cotyloideum,  it  is  necessary  to 
prepare  the  pelvis  of  a  cat  retaining  its  milk  teeth. 

§  448.  Arthron  ilio-sacrale — Ilio-sacral  articulation. — This  is 
the  articulation  between  the  sacrum  and  the  ilium.  In  the  figure 
the  arthral  surface  on  the  ilium  is  brought  into  view  by  the  re- 
moval of  part  of  the  sacrum.  The  caudal  third  of  this  surface  is 
diartJirodial^  the  cephalic  two  thirds  o.mpMartlirodial ;  the  motion, 
however,  is  very  limited. 

The  lateral  masses  of  only  the  first  sacral  vertebra  articulate 
directly  with  the  ilium. 

§  449.  Crista  ilii — Iliac  crest. — The  iliac  crest  is  the  prominent 
dorso-cephalic  projection  of  the  ilium  (Fig.  30,  51,  §  230). 

§  450.  Fm.  (Foramen)  obturatoriiim — Obturator  or  thyroid 
foramen. — The  large  oblong  space  bounded  by  the  os  pubis  and 
the  ischium. 


168 


ANA  TOMICAL    TECHNOL  OGT. 


tfiiite'Ctu: 


§  451.  Fossa  cotyloidea — Cotyloid  fossa,  Acetabulum. — The 
cotyloid  fossa  is  a  deep  cup-shaped  cavity  in  the  lateral  aspect  of 
the  innominate  bone  which  articulates  diarthrodially  with  the  head 
of  the  femur.     The  third  of  the  circumference  of  the  cavity  next  the 

obturator  foramen  is  absent,  thus 
producing  the  cotyloid  notch.  A 
rough  depression  extends  from 
this  notch  about  half  way  across 
the  floor  of  the  fossa. 

§  452.  Ilium.— This  is  the  ce- 
phalic part  of  the  os  innomina- 
tum.  It  articulates  with  the 
sacrum  and  forms  a  considerable 
part  of  the  cotyloid  fossa. 

§  453.  Ischium — The  dorso- 
caudal  part  of  the  pelvic  bone. 
It  forms  a  large  part  of  the  coty- 
loid fossa  and  about  one  third  of 
the  pubic  symphysis. 

§  454.  Os  cotyloideum — Co- 
tyloid bone. — A  small  bone  form- 
ing the  ventral  part  of  the  floor 
of   the    cotyloid   fossa.      Straus- 


Durckheim, 
Edwards,  A, 


A,    I,    502;    Milne- 
X,  358.     It  has  not 


been  detected  in  man,  and  can  be 
seen  as  a  separate  bone  only  in 
immature  cats. 

§  455.  Os  innominatum — In- 
nominate or  pelvic  bone. — The  os 
innominatum  is  made  up  of  the 
ilium,  the  iscJiium,  the  os  puMs 
and  the  os  cotyloideum.  These 
four  bones  are  completely  united 

in  adult  life.     The  right  and  left  pelvic  bones  together  form  the 

pelvic  girdle. 

§  456.    Os  pubis— Pubic  bone.— It  is  the  cephalo-ventral  of  the 

bones  forming  the  pelvic  girdle.     It  forms  only  a  small  part  of  the 

cotyloid  fossa  and  about  two  thirds  of  the  symphysis  pubis. 

%  457,   Pelvis,  a^.— ''The  two  innominate  bones,  together  with 


Fig.  51.— Ventral  View  op  the  Cat's 
Pelvis  with  Adjacent  Vektebr^. 
(Modified  from  Straus-Durcklieim.) 
xl. 


COLUMNA     VEIITEBRALIS.  169 

the  sacrum,  form  the  pelvis,  a  complete  circle  of  bone,  or  rather  a 
short  tube.' '-Flower,  A,  284. 

Pre.  trans..  Processus  transversus.  —  Transverse  process  or 
diapophysis  of  the  7th  lumbar  vertebra. 

§  458.  Saerum,  az. — "  The  portion  of  the  vertebral  column  to 
which  the  pelvic  girdle  is  attached."  It  is  composed  of  three  ver- 
tebrae, which  in  adult  life  are  more  or  less  completely  consolidated. 

In  an  immature  cat  which  would  show  well  the  lines  of  demar- 
cation between  the  bones  forming  the  Os  innominatum,  the  sacral 
vertebrae  would  be  but  partly  coossified. 

§  459.  Symphysis  pubis,  az. — This  is  the  linear  articulation 
(ampMarilirodial)  between  the  ventral  aspects  of  the  two  innomi- 
nate bones.  Its  cephalic  three  fourths  is  formed  by  the  Os  pubis 
and  the  caudal  fourth  by  the  ischium.  In  fully  adult  animals  the 
symphysis  usually  becomes  anchylosed. 

Vert.  (Vertebra)  lumbalis. — The  last  or  7th  lumbar  vertebra 

(Fig.  m). 

Vertebrae  caudales,  az. — Tail  vertebrae. — These  follow  imme- 
diately after  the  sacrum  (Fig.  30). 

§  4G0,   In  addition  to  tlie  parts  named  above,  the  following  should  be  mentioned : — 

A.  IVie  lliopectinecil  Line  and  Eminence. — Neither  are  shown  in  Sfcraus-Durckheim's 
figure,  from  which  this  was  copied.  Both  should  show  on  the  right  side,  however.  The 
line  extends  from  the  ilio-sacral  articulation  to  the  most  prominent  part  of  the  pubis. 
Opposite  the  cephalic  edge  of  the  acetabulum  the  line  presents  an  eminence  which  is  at  or 
very  near  the  junction  of  the  ilium  and  pubis. 

B.  The  Tuberosity  of  tlie  Ischium. — This  is  the  most  prominent  thickened  part  of  the 
ischium.  It  forms  the  extreme  dorso-caudal  part  of  the  whole  pelvis.  It  is  upon  this  part 
the  cat  rests  when  sitting  on  her  haunches. 

COLUMNA    VERTEBRALIS. 

References.— Strau3-Durcklieim,  A,  458  ;  Quain.  A,  I,  9,  25  ;  Gray,  A,  132  ;  Hum- 
phrey,  A,  113  ;  Milne  Edwards,  A,  X,  325  ;  Leyh,  A,  153  ;  Chauveau,  A,  19  ;  Owen,  A, 
II,  483  ;  Owen,  231  ;  Cuvier,  A,  1,  170  ;  Flower,  A,  10  ;  Mivart,  3  and  24 ;  Maclise, 
A,  G22  ;  Cleland,  7  and  13  ;  Wilder,  lO. 

§  461.  The  Columna  vertebralis,  spine,  vertebral  or  spinal  col- 
umn, consists  of  a  series  of  osseous  segments  called  vertebrcB  arranged 
in  close  connection  with  each  other  and  forming  tlie  bony  axis  of  the 
body.  It  is  nearer  the  dorsal  than  the  ventral  aspect  in  the  cat 
and  in  most  other  Vertebrates.  Its  position  and  curves  are  shown 
in  Fig.  30.    It  is  prolonged  caudad  beyond  the  trunk  to  form  the 


170  ANATOMICAL    TECHNOLOGY, 

axial  support  of  the  tail ;  and  cephalad  it  is  articulated  diarthro- 
dially  witli  the  occipital  region  of  the  skull.  ' '  The  different  verte- 
brae, with  some  exceptions  (§  458),  remain  through  life  distinct  from 
each  other,  though  closely  connected  by  means  of  fibrous  struc- 
tures which  permit  a  certain  but  limited  amount  of  motion  between 
them." 

§  462.  "Although  the  vertebrse  of  different  regions  present 
great  diversities  of  form,  there  is  a  certain  general  resemblance 
among  them  showing  a  common  plan  of  structure.  This  plan  is, 
however,  worked  out  variously  in  different  regions  by  change  of 
form  and  the  suppression  or  superaddition  of  parts,  thus  fitting 
them  to  fulfill  their  special  purpose." — Flower,  A,  10. 

In  general,  each  vertebra  is  composed  of  a  solid  subcylindrical 
centrum  or  body,  and  a  bony  ai^ch  (neural  arch),  with  various 
processes,  extending  dorsad  therefrom  (Fig.  b2-^5i). 

%  463.  Regions  of  the  Vertebral  Column. — For  convenience  of 
description,  the  whole  vertebral  column  has  been  divided  into  five 
regions,  named  in  order  from  the  head  : — Cervical  (7)  ;  Thoracic  or 
Dorsal  (13) ;  Lumbar  (7)  ;  Sacral  (3)  ;  Caudal  or  Tail  (22),  (Fig.  30). 

The  middle  Cervical,  Thoracic  and  Lumbar  vertebrae  are  shown 
in  Fig.  53-55,  where  the  special  characters  of  these  three  groups  are 
well  illustrated. 

§  464.  Distinguishing  the  Five  Groups  of  Vertebrae  and  the 
Ends  of  the  First  Four  Groups. — The  cervical  vertebrae,  except  the 
7th,  are  distinguished  by  the  j)resence  in  the  diapophysis  of  the 
vertehr  arterial  foramen  (§  473). 

The  7th  cervical  is  distinguished  from  the  thoracics  by  the  ab- 
sence from  its  prominent  diapophysis  of  an  Arthron  tuberculin  and 
by  the  absence  of  an  Arthron  capitelli  from  the  cephalic  end  of  the 
centrum  (Fig.  52).  It  differs  from  the  other  groups  by  its  short 
wide  centrum,  large  neural  foramen  and  slender  neural  spine. 

The  thoracic  vertebrae  differ  from  all  the  others  by  the  presence 
of  an  Arthron  capitelli  on  the  cephalic  end  of  the  centrum  or  upon 
both  ends. 

The  lumbar  vertebrae  may  be  distinguished  by  their  long  sub- 
cylindrical  centra,  and  by  the  cephalic  inclination  of  the  neura- 
pophyses  and  of  all  the  diapophyses  except  the  first. 

The  sacral  vertebrae  are  more  or  less  completely  ancJiylosed, 

The  caudal  vertebrae  differ  from  the  others  by  the  smallness  or 


CERVICAL     VERTEBR2E.  171 

absence  of  the  neural  foramen,  the  caudal  inclination  of  the  dia- 
pophyses  when  j^resent,  and  by  the  presence  in  some  (2d  to  9th)  of 

the  so-called  cJiewon  hones. 

%  4Gj.  The  che.i'Ton  hones  are  small  ossicles  attaclied  to  the  cephalo- ventral  part  of  the 
caudal  vertebrae  and  forming  an  open  or  closed  arch  through  which  passes  the  caudal  con- 
tinuation ot  the  A:  Sana  media. 

The  ends  oi  the  vertebraB  may  be  distinguished  very  readily  by  remembering  that  the 
arthral  surfaco  oi  the  prmzygapophjjsis  (Fig.  53),  situated  at  the  cephalic  end  of  the  verte- 
bra, faces  either  dorsad  or  dorso-mesad,  while  that  of  the  postzygapophysis  faces  ventrad 
or  ventro-laterad.  It  follows  from  this  that  the  postzygapophyses  overlie  the  prsezyga- 
pophyses  like  the  tiles  on  a  roof  Especially  in  the  thoracic  and  lumbar  regions,  the  Inci- 
sura  vertehralis  or  intervertebral  notch  is  much  deeper  on  the  caudal  than  on  the  cephalic 
side.     The  above  characters  apply  also  to  man. 

§  466.  Demonstration. — All  of  the  general  as  well  as  special 
points  relating  to  the  vertebral  column  may  be  demonstrated  on  a 
flexible  natural  skeleton  (§  252)  and  one  entirely  divested  of  its  soft 
parts.  The  relation  of  the  myelon  and  other  soft  parts  must  of 
course  be  demonstrated  on  a  fresh  or  alcoholic  specimen. 

§  467.  Preparation — (Fig.  52). — The  cleaning  (§  252),  was  carried  sufficiently  far  to 
divest  this  part  of  the  vertebral  column  of  all  its  soft  parts  except  the  intervertebral  flbro- 
cartilages. 

§  4G8.  Arthron  capitelli — Capitellar  articulation.— This  is  the  diarthrodial  arthral  cav- 
ity formed  in  two  adjacent  thoracic  vertebrae  for  the  reception  of  the  capiteUum  or  head  of 
the  rib  (Fig.  50).  The  part  of  the  articulation  in  each  vertebra  is  called  a  dcmifacet.  The 
12th  and  13th  vertebrae  have  each  a  complete  capitellar  arthral  surface.  The  caudal  part 
of  tlie  last  cervical  vertebra  supports  part  of  the  capitellum  of  the  first  rib ;  Flower,  A,  23. 

§  489.  Arthron  tuberculi. — This  is  the  diarthrodial  facet  on  the  diapophysis  for 
articulation  with  the  rib  corresponding  in  number  to  the  vertebra  from  which  the  dia- 
pophysis arises  (Fig.  50,  52;.     It  is  not  present  in  tl-ie  last  two  thoracic  vertebrae. 

§  470.  Atlas. — The  atlas  is  t\\Q  first  cervical  vertebra,  and  thus  the  first  of  tlie  entire 
series.  It  articulates  diarthrodially  with  the  occipital  condyles  (Fig.  57).  The  broad  lat- 
eral masses  are  the  dlapopliyscs  or  transverse  processes,  and  are  sometimes  called  "  wings 
of  the  atlas." 

§  471.  Axis. — This  is  the  second  of  the  cervical  vertebrs;.  It  articulates  diarthrodi- 
ally with  the  atlas,  but  with  the  third  vertebra  by  the  interposition  oi  fihro-cartilage,  that 
is,  amphiarthrodlally,  like  the  remaining  vertebrae,  except  the  sacrum  (§  458).  Its  neural 
spine  is  a  long  sharp  ridge  (Fig.  30). 

Cerv. — Vertebrae  cervicales,  cervical  vertebrae  1-7. 

§  473.  Fibro-cartilago  intervertebralis,  az. — Intervertebral  fibro  cartilage. — Between 
each  of  the  centra,  except  the  first  and  second  and  the  parts  of  the  sacrum,  is  this  very 
dense,  tough  and  elastic  fibrous  material.  "The  elasticity  provides  for  the  vertebrsB 
always  returning  to  their  normal  relation  to  each  other  and  the  column  generally  when 
they  have  been  disturbed  therefrom  by  muscular  action." — Flower,  A,  12. 

§  473.   Foramen  vert.,  Fm.  vertebrarteriale. — This  is  the  canal  through  the  bases 


172 


A  NA  TOMICAL     TECIIXOL  0  G  Y. 


of  the  diapophyses  of  all  but  the  last  (rarely  of  the 
last)  cervical  vertebrae.  Through  it  pass  the  verte- 
bral  artery  and  vein, 

§  474.  Foramen  atlantale — Atlantal  foramen. — 
This  is  a  passage  through  the  cephalic  edge  of  the 
atlas  just  dorsad  of  the  occipito-atlantal  arthron.  It 
transmits  the  first  or  suboccipital  nerve  and  the 
vertebral  artery  ;  Straus-Durckheim,  A,  I,  470.  It 
is  present  in  man  only  as  an  exception ;  Quain,  A, 
1,12. 

§  475.  Lamella  ventralis — Ventral  or  inferior 
lamella. — This  is  the  thin  plate-like  projection  ex- 
tending ventrad  from  the  diapophyses  of  some  of  the 
cervical  vertebrae.  It  is  most  marked  in  the  6th. 
Flower,  A,  32,  23. 

§  476.  Pre.  (Processus)  odontoideus,  az.— Odon- 
toid process. — This  is  a  tooth-like  projection  from  tlie 
cephalic  part  of  the  centrum  of  the  axis.  It  articu- 
lates diarthrodially  with  the  atlas,  and  serves  as  a 
pivot  on  which  the  atlas  and  head  rotate.  It  is  kept 
from  encroaching  upon  the  neural  canal  by  a  strong 
ligament. 

§  477,  Explanation  of  Fig.  53-55. — Anapophy- 
sis — Accessory  tubercle. — This  is  a  slender  process 
extending  laterad  from  the  caudal  part  of  the  neural 
arch.  It  is  ventrad  of  the  postzygapophysis,  and  with 
it  clasps  the  prsezygapophysis  of  the  following  verte- 
bra. It  is  present  in  the  first  six  lumbar  vertebrae,  and 
markedly  in  the  9th  to  the  13th  thoracics,  where,  in 
man,  it  is  called  the  inferior  tubercle ;  Quain,  A,  1. 14. 

§  478.  Arcus  neuralis,  az. — Neural  arch. — This 
is  a  bony  arch  projecting  from  the  dorsal  aspect  of 
the  centrum.  It  is  called  neural  arch  because  it  over- 
arches and  encloses  the  myelon  or  neural  axis. 

§  479.  Canalis  neuralis,  «2.— Neural  canal.— The 
neural  canal  is  formed  by  the  neural  foramina,  each 
foramen  being  a  short  segment  of  the  canal.  It  is 
enclosed  by  the  neural  arches  and  by  ligaments,  and 
contains  the  myelon. 

§  480.    Centrum,  «2.— Body.— The  vertebral  cen- 
trum is  the  solid  subcylindrical  ventral  portion  of  the 
vertebra.      Contiguous     vertebral    centra    articulate 
amphiarthrodially  by  means  of  an  interposed  disk  of  fibro-cartilage.     For  exceptions,  see 
§  458. 

§  481.  Diapophysis — Transverse  process, — The  diapopliysis  is  the  lateral  projection 
of  the  vertebra.  Its  base,  in  the  cervical  vertebrae  (Fig.  52),  except  the  7th,  contains  the 
'Dertehr arterial  foramen  (§  473). 

§  433.    Fm.  (Foramen)  neurale,  <zs.— Vertebral  ring  or  foramen. — This  is  the  space 


Adhfon. 

Fig.  53. — Ventral  Aspect  op 
THE  Cervical  and  op  two 
Thoracic  Vertebra.  (From 
Straus-Durckheim.)      xl. 


VERTEBB^. 


173 


enclosed  by  the  neural  arcli  and  the  dorsal  aspect  of  the  centrum.     The  neural  foramina 
of  all  the  vertebrae,  together  with  the  ligaments,  form  the  neural  canal. 

%  483.  Fm,  (Foramen)  vertebrarteriale. — This  foramen  is  found  in  the  base  of  the 
tliapophyses  of  all  the  cervical  vertebrae  except  the  last,  and  rarely  in  that.  In  man  it  is 
usually  present  in  the  last ;  Humphrey,  A,  142.  This  foramen  transmits  the  Arteria  et 
Vena  vertebralis  (Fig.  104)o 

§  484.   Inc.  (Incisura)  vertebralis — Notch. — The   pedicles  are  notched,  especially  on 
the  caudal  side.    When  the  vertebrae  are  united  these  notches 
form  the  so  called  intervertebral  foramina,  through  which 
pass  the  vessels  and  nerves  to  and  from  the  neural  canal. 

§  485.  Lm,  (Lamina)  neuralis — Lamina.— The  two 
laminae  form  the  roof  of  the  neural  arch.  Laterally  they  join 
the  pedicles,  and.  from  their  junction  at  the  meson  springs 
the  neural  spine. 

§  486.  Metapophysis — Mammillary  process. — This  is  a 
dorso-lateral  projection  of  the  praezygapophyses  of  the  lumbar 
vertebrae.  It  corresponds  to  the  internal  tubercle  of  the  tho- 
racic transverse  processes ;  Quain,  A,  I,  15. 

§  487.  Pedicle. — The  pedicle  of  a  vertebra  forms  the 
side  of  the  neural  arch.  It  extends  dorsad  and  joins  the 
lamina. 

§  488.   Praezygapophysis— Superior    articulating  process.— This  process  articulates 


Sp-na  neunUA 

^h^ 

4  .  Ji 

^Uiilt 

""yJiiafO-phyaiA^'' 

Fig.    53.— Caudal    View 

OF     THE     FOUKTH    CER- 

VICAL 

Vertebba;    xl. 

yeiUcLef 


^^Amrm'tuitKail 


'/Irthron  cofiUlii 


Jnd  verie 
6tali3 


fesr  tyi^apepkuaia 
apopkoM 
napephtfUM 


Fig.  54. — Caudal  View  of  the  Seventh 
Thoracic  Vertebra  ;  x  1. 


'Dlapophpi 

Fig.  55. — Caudal  View  of  the  Fourth 
Lumbar  Vertebra  ;    x  1. 


diarthrodially  with  the  postzygapophysis  of  the  preceding  vertebra.  The  arthral  surface 
of  this  process  faces  nearly  dorsad  or  dorso-mesad. 

§  489.  Postzygapophysis — Inferior  articulating  process. — The  postzygapophysis  ar- 
ticulates diarthrodially  with  the  praezygapophysis  of  the  vertebra  immediately  following 
it.     Its  arthral  surface  faces  nearly  ventrad  or  ventro-laterad. 

§  490.  Sp.  neu. — Spina  neuralis — Neural  spine.  Spinous  process,  az. — This  is  a 
raesal  process  arising  from  the  neural  arch  and  extending  approximately  dorsad. 


THE  SKULL. 

General  References  to  the  Skull.— Straus-Durckheim,  A,  I,  380 ;  Quain,  A,  I,  31  ; 
Gray,  A,  149  ;  Humphrey,  A,  175 ;  Darling  and  Ranney,  A,  17;  Cuvier,  A,  II,  177  ;  Owen, 


174  AIVATOMICAL    TECHNOLOGY. 

A,  IT,  492;  Flower,  A,  94;  Huxley,  B,  245;  Morrell,  A;  Milne  Edwards,  A,  X,  306; 
Oegenbaur,  A,  4'J3;  Leyb,  A,  122  ;  Chauveau,  A,  37 ;  Chauveau  (Fleming),  A,  33  ;  Parker 
and  Bettany,  A  ;  Parker,  25  ;  Turner,  4,  848-9  ;  Huxley,  3,  238  ;  Wyman,  76  :  Cuvier, 

B,  vn. 

§  491.  "  The  skull  (Fig.  56-62)  is  the  term  commonly  applied  to 
the  portion  of  the  axial  [somatic]  skeleton  situated  within  the  head." 
It  is  a  strong  bony  case  or"  frame  enclosing  the  brain  and  affording 
support  and  protection  to  the  organs  of  sight,  smell,  taste  and 
hearing. 

It  consists  of  several  irregular  bones,  most  of  which  are  immova- 
bly united  by  sutures  (synarthroses),  so  that  their  relative  position, 
and  hence  the  form  of  the  skull,  are  constant. 

In  addition  to  the  skull  proper,  there  are  articulated  to  its  base 
the  mandible  (Fig.  62)  and  the  fiyoid  apparatus  (Fig.  30,  §  224). 

§  492.  Cranium  and  Face. — For  convenience,  anatomists  have 
divided  the  skull  into  these  two  regions.  The  cranium  is  the  caudal 
part  of  the  skull ;  it  encloses  and  protects  the  brain.  The  face  is 
the  cephalic  part ;  it  surrounds  the  mouth  and  nasal  passages,  and, 
with  the  cranium,  completes  the  cavities  for  the  eyes.  Quain,  A,  I, 
31,  74 ;  Flower,  A,  94,  102. 

The  number  of  separable  bones  entering  into  the  formation  of  the 
skull  varies  with  the  age  of  the  animal.  The  teeth  are  not  included. 
The  bones  given  in  the  following  tables  and  figures  may  be  easily 
demonstrated  on  the  skull  of  a  cat  with  milk  teeth. 

§  493.  Sutures. — The  sutures  or  lines  of  union  between  the 
various  bones  of  the  skull  have  not  all  received  special  names,  bat 
all  may  be  properly  named  by  forming  a  compound  term  of  the 
names  of  the  two  bones  united,  as ;  Sutura  parieto-frontalis  in- 
stead of  S.  Goronalis  ;  S,  maxillo-prcdmaxillaris^  etc.  Quain,  A,  I, 
m,  58,  131. 

§  494.   Bones  of  the  Skull.     Modified  from  the  Tables  of  Quain, 
A,  74,  and  Flower,  A,  104.     (Fig.  56-62.) 

In  the  following  Tables  of  the  bones,  the  names  in  parenthesis  beneath  a  given  name 
are  synonyms ;  and  the  names  behind  the  small  or  secondary  braces  are  the  anthropo-  j 
tomiccd  equivalents  of  those  in  black  letter  behind  the  larore  braces. 

The  word  Os  (bone),  or  its  equivalent  0.,  is  to  be  understood  before  all  the  technical  • 
names  of  the  bones  excepting  Vomer  and  Mandibula. 


i 


MESAL(5).. 

(Single    or    Azy- 
gous  Bones). 


BONES    OF    THE    SKULL. 


CRANIUM. 


175 


BASIOCCIPITALE. 


BASISPHENOIDEUM. 


PR^SPHENOIDEUM . 


SUPRAOCCIPITALE. 


INTERPARIETALE. . . 


Basilar  process  of  the   occipital 

BONE. 

caudaii  part  of  the  body  of  the 
sphenoid  bone,  including  the 
sella  turcica. 

Cephalic  part  of  the  body  of  the 
sphenoid  bone. 

Tabular    part    op    the    occipital 

BONE. 

DORSO-CEPHALIC  ANGLE  OF  THE  TABU- 
LAR PORTION  OF  THE  OCCIPITAL. 


LATERAL  (10). 
(Paired  Bones). 


I 


EXOCCIPITALE 


PERIOTICUM 

(Pet  ro-m  a  stoide  um. 
Petrosuin  or 
Petrosale). 

TTMPANICUM 


SQUAMOSUM 

(Squamo-Zygomati- 
cum), 
PARIETALE 


ALISPHENOIDEUM.. 


PTERYGOIDEUM .. . 

ORBITO-SPHENOI- 

DEUM 

FRONTIS 


ETHMO-TURBINALE 


FACE 


J  MESETHMOIDEUM... 

(Single     or    Azygous 

Bones).  [  VOMER 


MESAL  (2) 


Condylar  portion  of  the  occipi- 
tal BONE. 

The  petrous  and  mastoid  por- 
tions op  the  temporal  bone  ; 

THE      first       including       THE 
labyrinth  and  MEATUS   AUDI- 
TORIUS  INTERNUS. 
The  TYMPANIC  RING  AND  AUDITORY 

PROCESS.  The  auditory  bulla 

AND  THE  POSTGLENOID  PART  OF 
THE  TEMPORAL  BONE. 

The  SQUAMOUS  part  of  the  tem- 
poral BONE  WITH  THE  ZYGO- 
matic process,  including  the 
arthral  surface  for  the 
mandible. 

The  PARIETAL  BONE. 

Great  wings  of  the  sphenoid 
bone  with  the  lateral  (ex- 
ternal) pterygoid  plates. 

The  MESAL  (INTERNAL)  PTERYGOID 
PLATES. 

The  LESSER  wings  of  the  sphe- 
noid BONE. 

The  frontal  bone. 

The  lateral  masses  with  the 
dorsal  and  ventral  turbi- 
nated bones  of  the  ethmoid, 

THE  cribriform  PLATE,  AND 
THE  OS  PLANUM  OR  ORBITAL 
PLATE  OF  THE  ETHMOID 


The  vertical  (mesal)  plate  of 

THE  ETHMOID  BONE,  INCLUDING 
THE  CARTILAGINOUS  NASAL 
SEPTUM. 

The  Vomer,  or  Os  vomeris. 


176 


A  NA  TOMICAL     TECHNOL  OGY. 


RAMUS  MANDIBULA- 
RIS 


PALATINUM, 
MAXILLARE . 


LATERAL  (8).  \  maxillo-turbinale 

(Paired  Bones). 


MALARE 

PR^MAXILLARE. 


LACHRYMALE. 
LNASALE 


The  two  rami  unite  to  form  the 

LOWER  JAW    or    mandible   OR 

maxilla  inferior. 

The  palate  bone. 

The  superior  maxillary  or  up- 
per JAW  BONE  EXCEPTING  THE 
INCISOR  PART. 

The  INFERIOR  TURBINATED  BONE. 

The  malar  bone. 

Intermaxillary,  the  incisor 
part  of  the  superior  maxil- 
lary bone. 

The  LACHRYMAL  BONE. 

The  nasal  bone. 


§  495.  Articulations  of  the  Bones  of  the  Skull.     (Fig.  54-60). 

The  following  list  represents  the  bones  approximately  as  given  in  standard  works  on 
Human  Anatomy.     Tliey  are  readily  distinguishable  in  a  nearly  adult  cat. 

The  parts  forming  a  compound  bone  are  given  in  parenthesis  immediately  below  the 
name  of  the  bone  under  consideration.     See  Os  occlpitale. 

The  Arabic  number  in  parenthesis,  after  a  bone  and  just  before  the  brace,  indicates  the 
number  of  bones  with  Avhich  it  articulates.  The  parts  of  a  compound  bone  are  numbered 
as  one.    See  Os  parietale. 

In  giving  the  articulations  of  the  mesal  bones,  the  Arabic  numeral  2  is  placed  in  paren- 
thesis after  all  the  lateral  bones  with  which  it  articulates,  to  indicate  that  it  is  connected 
with  botli.     See  Vomer. 

If  but  one  of  the  parts  of  a  compound  bone  articulates  with  a  given  bone,  the  name  of 
that  part  is  given  instead  of  the  name  of  the  whole  bone ;  but  if  more  than  one  compound 
enters  into  the  articulation,  the  name  of  the  whole  bone  is  given,  and  that  is  followed  by  a 
brace  and  the  names  of  the  components.    See  Os  parietale. 


0S0CCIPITALE(6). 

(Basioccipitale, 
Exoccipitale, 
Supraoccipitale,  with  the 
Interparietale). 


CRANIUM. 
CAUDAD 


CEPHALAD 


OS  SPHENOIDEUM  (13).. 

(Basisphenoideum, 
Alisphenoideum, 
Pterygoideum, 
Prsesphenoideum, 
Orbito-sohenoideum). 


CAUDAD 


DORSAD 


CEPHALAD 


Atlas. 


(  Parietale  (a), 
■j  Temporale  (2). 
(  Basisphenoideum. 

j  Basioccipitale. 
■j  Temporale^). 
r  Temporale  (2). 
J  Parietale  (2). 
]  Frontis  (2). 
[  Ethmoideum  (2). 
f  Palatinum  (2). 
I  Frontis  (2). 
•{  Ethmoideum  (3). 
j  Mesethmoideum. 
[  Vomer. 


ARTICULATIONS    OF    THE    SKULL. 


177 


OS  TEMP0RALE(6). 

(Perioticum, 

Tympanicum, 

Squamosum). 


CAUDAD... 
DORSAD... 

VENTRAD. 


MESAD. 


occipitale. 

Parietale. 

Ramus  mandibularis. 

Hyoides. 

Basioccipitale. 


CEPHALAD 


I 


Sphet^oideum. 

Sphenoideum. 

Parietale. 
[  Malare. 


Ali-  and  basi- 
splienoideum. 

Ali-  and  basi- 
sphenoideum. 


OS  PARIETALE  (5) 


CAUDAD.. 


VENTRAD.  . 


{  Supraoccipitale. 
■    \  Interparietale. 


occipitale 
Squamosum. 

T.MPOBA.....||?™-r 

Alisphenoideum. 

MESAD Parietale  {the  platetrope). 

CEPHALAD.      Frontis. 


OS  FRONTIS  (8) 


CAUDAD. . . . 

VENTRAD. 

MESAD 

CEPHALAD. 


Parietale. 

Alisphenoideum. 

Orbito  sphenoideum. 

Palatinum. 

Planum. 

Lachrymale. 

Os  Frontis  (the  platetrope), 
Ethmoideum. 
Ethmoideum. 
Maxillare. 

Nasale. 


OS  ETHMOIDEUM  (9)... 

(Ethmo-turbinal,  lamina  cribi-osa). 


r"ATTT\An  S  Frontis. 

L.AUi>AU ^  Pr^SPHENOIDEUM. 

DORSAD -Il--™- 

(  Pr^sphenoideum. 
VENTRAD. . .    •]  Maxillo-turbinal. 
(  Vomer. 

vrTTQArk  i  Mesethmoideum. 

^^^^^ I  Ethmoideum  {the  platetrope). 

i  Frontis. 
Maxillare. 
Palatinum. 


FACE. 

CAUDAD, 


OS  MESETHMOIDEUM  (8)..  J 


VENTRAD 
LATERAD. 


PRiESPHENOIDETJM. 


nm?«?AD  i  Frontis  (2). 

DOKbAD -j  Nasale  (2). 


Vomer. 
Ethmo-turbinale  (2). 


178 


ANATOMICAL    TECHNOLOGY. 


VOMER  (lo). 


CAUDAD. 
DORSAD. 


VENTRAD. 
LATERAD . 


Pr^sphenotdeibi. 
Mesethmoideum. 
Ethmo-tukbinale  (2). 
Palatinum  (2). 
Maxillare  (2). 
Pr^maxillake  (2). 
Palatinum  (2). 


RAMUS      MANDIBULA-   j  caudo-dorsad.  squamosum 
RIS  (3) 1  mesad 


Rm.  mndbl.  {the  platetrope). 


OS  PALATINUM  (7).- 


DORSAD... 


MESAD. 


LATERAD... 


m:^r»TTAT  A  TV    \  Lachrymal 
CEPHALAD.]  maxillare. 


Prjesphenoideum. 

Frontis. 

Ethmo-turbinale. 

Vomer. 

Palatinum  (tTie  platetrope), 

Ethmo-turbinale. 

Pr^sphenoideum. 

Vomer. 

Maxillare. 

Lachrymals. 


OS  MAXILLARE. 


CAUDAD.  .. 


MESAD. 


CEPHALAD. 


Frontis. 

Lachrymals. 

Palatinum. 

Malare. 

Maxillare  (the  platetrope). 

Vomer. 

Nasale. 

PR^MAXn.LARE. 

Ethmo-turbinale. 
Maxillo-turbinale. 
Palatinum. 
Pr^maxillare. 


OS  MAXILLO-TURBINALE  (4). 


'  CAUDAD Lachrymale. 

DORSAD Ethmo-turbinalk 

Maxillare. 
Frontis. 


LATERAD . . . 


OS  PRiEMAXILLARE  (3) 


i^ATTrvATi  ^  Maxillare. 

CAUDAD -^  y^^^^ 
MESAD Pmx.  {the  platdrope). 


OS  MALARE  (3).. 


(  ^  (  Processns 

CAUDAD -j  Temporale  . . .   |  ^^^gomaticus. 


MESO-CEPHALAD. 


Lachrymale. 


CEPHALAD I  Maxillare.  . .  | 


Processus 
malaris. 


DORSAL    ASPECT   OF    THE    SKULL, 


179 


OS  LACHRYMALE  (5) 


OS  NASALE  (6). 


CAUDAD \  Planum. 

\  Palatinum. 

^^^^ iFKo^r" 


LATERAD, 


Malare. 
Maxillare. 


CEPHALAD \  Maxillo-turbinalb. 

/  Maxillare.  • 


'  CAUDAD Frontis. 

VENTRAD ^  Ethmo-turbinal. 

(  Mbsethmoideum. 

MES  AD Nasale  {}he  platetrope). 

j  Maxillare. 
(  Pr^maxillare. 


LATERAD. 


All  the  figures  of  the  skull  are  of  J^elis  domestica. 

In  the  description  of  the  figures,  under  the  general  heads,  which  are  arranged  alphabefe- 
ically,  the  special  parts  are  named  commencing  at  the  caudal  extremity. 

For  fuller  information  concerning  any  of  the  bones  or  foramina,  refer  to  the  Table  of 
Bones  and  of  Foramina,  pp.  175,  190. 

§  496.  Preparation. — The  soft  parts  were  entirely  removed 
(g  250,  B).  The  roof  of  the  left  side  was  then  removed  by  sawing 
carefully  with  a  line  saw  to  the  meson  at  a  level  just  dorsad  of  the 
orbits  and  about  2  mm.  dorsad  of  the  foramen  magnum.  The 
frontal  and  parietal  bones  were  then  removed  with  nippers  by  sep- 
arating them  at  the  coronal,  the  sagittal  and  the  lambdoidal  sutures. 
Finally,  the  interparietal  and  supraoccipital  were  removed  by  saw- 
ing on  the  meson  till  the  first  incision  was  reached.  This  exposed 
the  frontal  sinus  and  the  ental  surface  of  the  base  of  the  skull. 

§  497.  Cn.  Ich.,  Canalis  lachrymalis— Lachrymal  canal. — This  canal  passes  ceph- 
alo-ventrad  and  lies  between  the  maxilla  and  maxillo-turbinal.  It  finally  opens  into  the 
nasal  cavity  just  ventrad  of  the  maxillary  attachment  of  the  maxillo-turbinal  and  nearly 
opposite  the  fang  of  the  canine  tooth. 

§  ii98.  Cst.  Imd.,  Crista  lambdoidalis. — The  lambdoidal  crest  corresponds  to  the 
superior  curved  line  of  the  occipital  in  Human  Anatomy.     Flower,  A,  112,  132. 

§  499.  Cst.  temp.,  Crista  temporalis— Temporal  crest.  —This  marks  the  dorsal 
limit  of  the  temporal  fossa  and  muscle.  In  young  cats  it  is  considerably  separated  from 
the  meson,  but  in  adults  it  approaches  it  and  may  be  mesal  from  the  lambdoidal  crest  to 
the  coronal  suture.     The  mesal  part  is  then  called  sagittal  cref^t  ;  Flower,  A,  112. 

Fm.  m.,  Foramen  magnum,  az. 

Fm.  j.,  Foramen  jugulare — 8.  lacerum  posterius. — Jugular  or  posterior  lacerated 
foramen. 

Fm.  ov.,  Foramen  ovale. 

•Fm.  rt.,  Foramen  rotundum. 
Fm.  1.  a..  Foramen   lacerum   anterius — s.  lacerum  orbitale,   s.  fissura  sphenoida- 
— Anterior  or  orbital  lacerated  foramen,  sphenoidal  fissure. 
Fra.  op.,  Foramen  opticum — O^^tic  foramen. 


180 


ANAT03IICAL     TECHNOLOGY. 


§  500,  Fm.  pit.,  Foramen  palatinum  posterius — Posterior  palatine  foramen. — Tho 
passage  between  the  opening  shown  in  this  figure  and  Fig.  60  is  known  as  the  posterior 
palatine  canal.     Quain,  A,  I,  373. 

§  501.  Fm.  sphplt.,  Foramen  spheno-palatinum — Spheno-palatine  foramen. — It 
leads  from  the  orbit  into  the  nasal  cavity. 


Fig.  56.— Dorsal  View  of  the  Skull  ;    x  1.3. 


§  503.  Fs,  ap.,  Fossa  appendicularis. — Fossa  for  the  appendicular  lob^^of  the 
cerebellnm. 

§  503.  Fs,  (Fossa)  temporalis — Temporal  fossa. — This  is  the  space  on  the  side  of 
tho  skull  caudad  of  the  postorbital  process  of  the  frontal.  By  mistake,  the  name  in  this 
figure  is  written  partly  in  the  orbit. 

§  504.  Fossa  orbitalis— Orbital  fossa,  orbit.— In  this  space  the  eyes  are  found  in 
living  animals.  Unlike  the  orbital  fossa  of  man,  that  of  the  cat  is  not  separated  from  the 
Vemporal  by  a  plate  of  bone,  but  opens  widely  into  it. 


DORSAL    ASPECT    OF    THE    SKULL.  181: 

§  505.  I.,  Infundibulum. — This  is  the  opening  from  the  frontal  sinus  to  the  nasal 
cavity. 

§  506.  M.  a.  i.,  Meatus  auditorius  internus — Internal  auditory  meatus. — This  is 
divided  into  two  parts  very  near  its  mouth,  as  shown  by  the  white  line.  The  ventral  part 
receives  the  auditory  nerve  (VIII),  the  dorsal  part,  X\\e  facial  (Vll).  The  facial  in  its  course 
curves  round  in  the  dorso-lateral  part  of  the  Pars  petrosa  and  finally  emerges  at  the  stylo 
mastoid  foramen.  This  passage  throucrh  the  skulJ  from  the  M.  a.  i.  to  the  stylo-mastoid 
foramen  is  known  as  the  Aquaeductus  Fallopii.  In  the  Pars  petrosa,  about  2  mm.  from 
its  mouth,  there  branches  cephalad  a  small  canal,  the  Hiatus  Fallopii^  which  opens  oppo- 
site the  ventral  end  of  the  osseous  tentorium. 

§  507.  O.  soc,  Os  supraoccipitale,  az, — Supraoccipital  bone. — This  forms  the  caudal 
part  of  the  roof  of  the  cranial  cavity. 

§  503.  O.  i.  p.,  Os  interparietale,  «s. — Interparietal  bone. — A  small  bone,  separate  in 
young  animals.  It  is  cephalad  of  the  supraoccipital  and  is  wedged  in  between  the  caudal 
ends  of  the  parietals. 

§  5U9.  O.  parietale — Parietal  bone. — The  parietal  bone  forms  a  large  part  of  the  side 
and  roof  of  the  cranial  cavity. 

§  510.  O.  perioticum — s.  petrosum. — This  is  a  part  of  the  temporal  bone ;  it  encloses 
the  internal  ear,  and  is  divided  into  two  parts,  Pars  petrosa  and  Pars  mastoidea,  the  latter 
appearing  on  the  ectal  surface  of  the  skull  (Fig.  57). 

§  511.  O.  temporale — Temporal  bone. — This  forms  part  of  the  floor  and  side  of  the 
cranium,  and  by  its  zygomatic  process  helps  to  enclose  the  temporal  fossa. 

§  512.  O.  boc,  Os  basioccipitale,  az. — Basioccipital  bone. — It  forms  part  of  the  floor 
of  the  cranium. 

g  513.  O.  bsph.,  Os  basisphenoideum,  az. — It  forms  the  caudal  part  of  the  body  of 
the  sphenoid  bone,  and  helps  to  make  the  floor  of  the  cranial  cavity. 

§  514.  O.  alsph.,  Os  alisphenoideum, — This  is  one  of  the  greater  wings  of  the  sphe- 
noid and  forms  part  of  the  side  and  floor  of  the  cranium. 

§  515.  O.  orsph.,  Os  orbito-sphenoideum. — This  is  one  of  the  lesser  wings  of  the 
sphenoid ;  it  forms  part  of  the  floor  and  side  of  the  cranium  and  part  of  the  mesal  wall 
of  the  orbit. 

§  516.  O.  frontis — The  frontal  bone, — The  frontal  bone  forms  a  large  part  of  the  roof 
and  part  of  the  side  of  the  cephalic  region  of  the  cranial  cavity  and  the  mesal  wall  of  the 
orbit.     It  also  covers  the  caudal  part  of  the  nasal  cavity. 

§  517.  O.  pit.,  Os  palatinum — Palate  bone. — This  is  a  very  complex  bone,  forming, 
part  of  the  orbit,  of  the  roof  of  the  mouth,  and  of  the  floor  and  side  of  the  nasal  cavity, 

§  518.  O.  malare — s.  Os  zygomaticura,  os  jugale— Malar,  zygomatic  or  jugal  bone. — 
This  bone  connects  the  malar  and  zygomatic  processes  of  the  maxilla  and  the  temporale,  and 
with  them  encloses  laterally  the  orbit  and  the  temporal  fossa,  and  completes  the  Zygoma 
or  zygomatic  arch. 

§  519.  O.  pin.,  Os  planum. — This  is  not  a  separate  bone,  but  merely  the  orbital  part 
of  the  ethmo-turbinal.     It  is  often  absent. 

§  520.  O.  Ich.,  Os  lachrymale — Lachrymal  bone. — It  is  a  thin  quadrilateral  bone 
forming  part  of  the  cephalic  wall  of  the  orbit  and  the  caudal  part  of  the  nasal  cavity. 

§  521.  O.  maxillare— Maxilla,  superior  maxillary  or  upper  jaw  bone. — This  is  a  com- 
plex bone  which  forms  a  great  part  of  the  face.  In  it  are  implanted  the  dorsal  (upper) 
molar,  prseraolar  and  canine  teeth. 

§  523,  O.  nasale — Nasal  bone.  —A  thin  irregular  bone  forming  part  of  the  roof  of  the 
nasal  cavity. 


182 


ANATOMICAL    TEUIINOLOGT. 


FiQ.  57. — Ventral  Aspect  or  base  of  the  Skuli..     (Modified  from  Swaus-Durck- 

heim)  ;   x  1.75.  • 

§  533.  O.  pmx.,  Os  praemaxillare — Prsemaxillaiy  or  intermaxillary  bone.— It  forms 
ihe  most  cephalic  part  of  the  skull,  and  in  it  are  implanted  the  dorsal  (upper)  incisor 
teeth. 

Pre.  z.,  Processus  zygomaticus. — Zygomatic  process  of  the  temporal  bone. 


BASE    OF    THE    SKULL.  183 

Pre.  po.,  Processus  postorbitale. — Post  orbital  process  of  the  frontal  bone. 

§  524.  S.  (Sinus)  frontalis — Frontal  sinus — This  cavity  in  the  frontal  bone  is  sep- 
arated from  its  piatetrope  by  a  bony  partition  (Fig.  GO).  It  communicates  with  the  nasal 
cavity  through  the  infandibulum  (I.)  and  is  lined  by  an  extension  of  the  nasal  mucous 
membrane. 

§  525.  Sutura  lambdoidalis,  az. — Lambdoidal  or  occipitoparietal  suture. — This  is  the 
synarthrodial  articulation  between  the  parietal,  the  interparietal  and  the  supraoccipital 
bones. 

§  523.  Sutura  sagittalis,  «s. — Sagittal  suture, — The  synarthrodial  articulation  between 
the  right  and  left  frontal  and  the  parietal  bones.  It  extends  from  the  nasal  bones  to 
the  lambdoidal  suture. 

In  Human  Anatomy,  the  sagittal  suture  is  confined  to  the  articulation  of  the  two  parie- 
tals  with  each  other,  the  two  frontals  uniting  so  early  that  they  are  considered  as  a 
single  bone. 

§  527.  Sutura  coronalis — Coronal  or  parieto-frontal  suture. — The  synarthrodial  artic- 
ulation between  the  frontal  and  parietal  bones. 

§  528.  Fig.  57 — Preparation.  —  The  skull  was  tlioroiighly 
cleaned,  and  while  still  moist  the  following  structures  were  removed 
from  the  right  side : — 

(A)  The  tympanic  bulla  was  removed  by  inserting  an  arthro- 
tome  between  it  and  the  basioccipital  and  prying  steadily,  thus 
exposing  the  Pars  petrosa^  the  Foramen  lacerum  jugulare  and  Fm. 
lacerum  medium^  the  Fenestra  ovalis  and  Fenestra  rotunda. 

(B)  The  Os  pterygoideum  and  a  part  of  the  Os  palatinum  were 
removed  by  the  nippers  to  expose  the  row  of  foramina. 

(C)  The  teeth  were  extracted  with  the  nippers  to  expose  the 
alveoli  (sockets  of  the  teeth). 

a,  b. — Fractures  made  in  removing  the  bulla. 

Bulla  tympanica. — Tympanic  or  auditory  bulla  (Fig.  58). 

§  529.  Cd.  oc,  Condylus  occipitalis — Occipital  condyle. — The  occipital  condyle  is 
formed  mostly  by  the  exoccipital,  but  somewhat  also  by  the  basioccipital.  It  articulates 
diarthrodially  with  the  atlas. 

Cn.  eu.,  Canalis  Eustachiana. — Eustachian  canal  (Fig.  58). 

D.  m.,  Dens  molaris. — Molar  tooth. 

DD.  pm.,  Dentes  praemolares. — Praemolar  teeth. 

D.  c,  Dens  caninus. — Canine  tooth. 

DD.  i.,  Dentes  incisores. — Incisor  teeth. 

Fm.  m.,  Foramen  magnum,  az. 

%  530.  Fm.  cd.,  Foramen  condylare — Condylar  foramen. — This  foramen  is  some- 
times nearly  hidden  either  by  the  projection  of  the  bulla  or  its  unusual  approach  to  the 
Fm.  jugulare. 

§  531.  Fm.  j..  Foramen  jug^ulare — 5.  lacerum  posterius. — Jugular  or  posterior  lacer- 
ated foramen. 

§  532.  Fm.  stm..  Foramen  stylo-mastoideum— Stylomastoid  foramen. — This  is 
the  ectal  termination  of  the  Aquceductus  Fallopii  (Fig.  56,  59,  M.  a.  i.). 

§  533.   Fm.  1.  m..  Foramen  lacerum  medium — s.  Fm.  spheno-petrosum — Middle 


184  ANATOMICAL    TECHNOLOGY. 

lacerated,  or  spheno-petrosal  foramen. — The  opening  of  this  foramen  on  the  ectal  sur- 
face of  the  skull  is  just  within  the  mouth  of  the  Eustachian  canal.  It  perforates  the  lateral 
edge  of  the  cephalic  projection  of  the  bulla,  and  may  be  seen  on  most  prepared  skulls  by- 
looking  into  the  mouth  of  that  canal. 

The  existence  of  the  Foramen  lacerum  medium  in  the  cat  is  not  mentioned  by  any  of 
the  authorities,  so  far  as  we  are  aware  ;  but  the  foramen  so  named  in  this  figure  is  between 
the  cephalic  extremity  of  the  pars  petrosa  and  the  alisphenoideum — the  position  occupied 
by  the  foramen  lacerum  medium  in  man,  as  stated  by  Quain,  A,  I,  62,  and  in  the  dog,  as 
stated  by  Flower,  A,  101.  This  foramen  in  the  cat  also  transmits  an  artery,  which  has 
been  called  internal  carotid  in  the  table  of  foramina  (§  562).  It  is  so  called  since  it  anas- 
tomoses with  the  cerebral  vessels  within  the  cranium,  and  arises  from  the  carotid  at  tlrr' 
proper  place — slightly  centrad  of  the  origin  of  the  lingual.  It  passes  along  the  carotid 
canal  and  unites  with  a  larger  vessel  extending  along  the  raesal  side  of  the  bulla.  The 
artery  is  imbedded  in  the  wall  of  the  Eustachian  tube  m  its  passage  along  the  Eustachian 
canal  to  the  foramen. 

Fm.  ov.,  Foramen  ovale. 

Fm.  rt.,  Foramen  rotundum. 

§  534.  Fm.  1.  a.,  Foramen  lacerum  anterius — s.  fissura  sphenoidalis. — Anterior 
lacerated  foramen  or  sphenoidal  fissure. 

Fm.  op.,  Foramen  opticum,  transmitting  the  Nervus  opticus. 

§  535.  Fm.  pit.  p.,  Foramen  palatinum  posterius — Posterior  palatine  foramen. — 
There  are  usually  two  openings  of  the  posterior  palatine  canal  in  the  roof  of  the  mouth  as 
shown  in  this  figure.     (See  also  Fig.  56.) 

Fm.  pit.  a.,  Foramen  palatinum  anterius — s.  Fm.  incisore.— Anterior  palatine  or 
incisor  foramen. 

§  536.  Fs.  tyh.,  Fossa  thyrohyalis. — This  is  the  pit  into  which  is  inserted  the 
dorsal  part  of  the  Os  hyoides  (i^  224). 

g  537.  Fs.  (Fossa)  mandibularis — Mandibular  or  glenoid  fossa. — This  receives  the 
mandibular  condyle  and  articulates  diarthrodially  with  it  (Fig.  62). 

§  538.  Ft.  rt.,  Fenestra  rotunda — This  opening  connects  the  tympanum  with  tlio 
scala  tympani  of  the  cochlea.     In  the  living  body  it  is  covered  with  membrane. 

§  539.  Ft.  ov..  Fenestra  ovalis. — This  connects  the  tympanum  with  the  vestibu/a. 
In  living  bodies  it  is  closed  by  the  stapes  and  its  connecting  soft  structures. 

§  540.  M.  a.  e.,  Meatus  auditorius  externus— External  auditory  meatus.— This 
extends  from  the  side  of  the  head  to  the  ectal  surface  of  the  Membrana  tympani. 

§  541.  Margo  alveolaris — Alveolar  margin  or  border  of  the  jaw. — In  this  border  of 
the  jaw  the  teeth  are  implanted. 

O.  supraoccipitale,  az. — Supraoccipital  bone. 

O.  exoc,  Os  exoccipitale. — Exoccipital  bone. 

O.  basioccipitale,  az. — Basioccipital  bone. 

O.  basisphenoideum,  az. — Basisphenoid  bone. 
.     O.  alsph.,  Os  alisphenoideum  (Fig.  56). 

O.  pt.,  Os  pterygoideum. — Pterygoid  bone.  -"^ 

O.  praesph.,  Os  praesphenoideum,  az. 

O.  orsph.,  Os  orbito-sphenoideum  (Fig.  56). 

O.  frontis  (Fig.  56). 

O.  vm.,  Os  vomeris. — Vomer  (Fig.  v59). 

O.  palatinum. — Palate  bone  (Fig.  56). 

O.  malare. — Malar  bone  (Fig.  56). 

O.  maxillare. — Maxillary  or  upper  jaw  bone  (Fig.  56). 


THE    BULLA     TYIIFA^ICUM. 


185 


O.  pmx.,  Os  praemaxiiiare. — Prsemaxillary  or  intermaxillary  bone. 

§  542.  Pre.  par.,  Processus  paroccipitalis — s.  pararaastoideus — Paramastoid  or 
paroccipital  process. — This  is  a  curved  shelf-like  projection  of  the  exoccipital  which  abuts 
against  the  caudal  end  of  the  bulla. 

Pre.  pro.,  Processus  mastoideus — s.  pars  mastoidea.— Mastoid  portion  of  the  peri- 
oticurii. 

Pre.  z.,  Processus  zygomaticus. — Zygomatic  process  of  the  temporal  bone. 

Pre.  po.,  Processus  postorbitaie. — Postorbital  process  of  the  frontal  bone. 

§  543.  Fig.  58— Preparation,— The  soft 
l)arts  were  removed  ;  tlien,  while  the  skull 
was  yet  moist,  the  ventral  face  of  the  bulla 
was  ground  off  on  a  fine  emery-stone. 
It  might  be  removed  with  a  watch-spring 
saw  or  on  an  ordinary  grindstone.  In 
grinding,  the  pressure  should  be  only 
moderate  to  avoid  breaking  the  delicate 
septum. 

§  544.  Bulla  tympanica — The  auditory  or  tympanic 
bulla. — The  bulla  is  a  hollow  subspherical  part  of  the 
0.  tympanicum  enclosing  the  tympanum  or  middle  ear. 
A  delicate  bony  septum  divides  the  cavity  into  two  un- 
equal parts.  This  septum  arises  from  the  floor,  and 
extends  dorsad,  but  leaves  a  space  over  the  fenestra  ro- 
tunda which  puts  the  two  chambers  in  communication. 

In  the  lateral  aspect  of  the  bulla  is  the  external  auditory  meatus  (M.  a.  e.) ;  attached  to 
the  octal  part  of  this  is  the  external  car,  and  to  the  ental  part  the  Memhrana  tympani  or 
ear  drum,  which  completely  separates  the  tympanum  or  middle  ear  from  the  exterior  of 
the  body.     Flower,  A,  110,  and  26,  4  ;  Huxley,  B,  249  ;  Straus-Durckheira,  A,  I,  409. 

Cd.  DC,  condylus  occipitalis. — Occipital  condyle. 

§  545,  Cn.  eu.,  Canalis  Eustachiana — Eustachian  canal. — This  is  a  short  bony  tube 
leading  from  the  tympanum  to  the  ventral  surface  of  the  skull.     Flower,  A,  111. 

Fm.  m..  Foramen  magnum,  az. 

Fm.  cd.,  Foramen  condylare. — Condylar  foramen. 

Fm.  ov.,  Foramen  ovale. 

Fs.  mnd.,  Fossa  mandibularis. — Mandibular  or  glenoid  fossa  (Fig.  57), 

Ft.  rt.,  Fenestra  rotunda  (Fig.  57). 

Ft.  ov.,  Fenestra  ovalis, 

M.  a.  e..  Meatus  auditorius  externus. — External  auditory  meatus. 

O.  boc,  Os  basioccipitale,  az. — Basioccipital  bone. 

Pre.  z..  Processus  zygomaticus. — Zygomatic  process  of  the  temporal  bone. 

Spt.  tym..  Septum  tympanicum. — The  bony  partition  dividing  the  interior  of  the 
bulla  into  two  unequal  chambers. 

§  546.  Fig.  59 — ^Preparation. — The  soft  parts  were  removed 
(§  250,  B),  and  then  the  section  was  made  with  a  watch-spring  saw 
while  the  skull  was  still  moist.    The  section  was  made  about  2  mm. 


Fig.  58.  —  Ventbo  -  lateral 
View  of  the  Left  Bulla 
AND  Adjacent  Pakts  :  x  1.5. 


18G 


ANA  T03IICAL     TECHNOL  OGY. 


to  the  left  of  the  meson  to  avoid  injuring  the  mesethmoideum  and 
other  mesal  parts.  The  remaining  parts  of  the  left  half  were  altei- 
ward  removed  with  the  nippers  ;  the  septa  of  the  frontal  and  sphe- 
noidal sinuses  were  likewise  partly  removed. 


Fig.  59. — Hemisection  of  the  Skull,  Right  Side:  xl.5. 


Bulla  tym.,  Bulla  tympanica. — Tympanic  or  auditory  bulla  (Fig.  58). 

Fm.  j.,  Foramen  jugulare— s.  Fm.  lacerum  posterius. — Jugular  or  posterior  lacer- 
ated foramen. 

Opposite  tlie  occipital  condyle  and  nearly  caudad  of  the  condylar  foramen  is  an  un- 
named openinof  for  a  vein. 

Fm.  op.,  Foramen  opticum. — Optic  foramen. 

Fm.  sphplt.,  Foramen  spheno-palatinum. — Sphenopalatine  foramen. 

Fs.  ap.,  Fossa  appendicularis  (Fig.  56). 

§  547.  Fossae  of  the  Cranial  Cavity. — (A)  Fossa  cerebellaris,  az. — Cerebellar 
fossa. — This  is  the  part  of  the  cranial  cavity  caudad  of  the  osseous  tentorium.  It  contains 
the  cerebellum  and  medulla  (Fig.  88). 

(B)  Fossa  cerebralis,  az. — Cerebral  fossa. — This  is  the  part  of  the  cavity  of  the  skull 
between  the  tentorium  caudad  and  the  olfactory  fossa  cephalad.  Ii_£pntains  the  cere- 
brum, thalamus,  part  of  the  optic  lobes  and  the  crura  (Fig.  88). 

(C)  Fossa  olfactoria — s.  rhinencephalica — Olfactory  or  rhinencephalic  fossa. — This 
is  the  smallest  of  the  fossae.  It  is  limited  cephalad  by  the  Lamina  cribrosa  and  extends 
caudad  to  the  dorso-ventral  ridge  formed  by  the  frontal  and  orbito-sphenoid.  It  lodges 
the  rhinencephalon  or  olfactory  lobes  (Fig.  88). 

M.  a.  i.,  Meatus  auditorius  internus. — Internal  auditory  meatus  (Fig.  57). 
O.  exoc,  Os  exoccipitale. — Exoccipital  bone  (Fig.  56). 
O.  soc,  Os  supraoccipitale,  az. — Supraoccipital  bone. 


HEMISECTION    OF    THE    SKULL,  187 

O.  ip.,  Os  interparietale,  az. — Interparietal  bone. 

O.  boc,  Os  basioccipitale,  az. — Basioccipital  bone. 

O.  pro.,  Os  perioticum. — Periotic  bone  (Fig.  59). 

O.  bsph.,  Os  basisphenoideum,  az. — Basisphenoid  bone. 

O.  temporale. — Temporal  bone. 

O.  parietale. — Parietal  bone  (Fig,  50). 

O.  pt.,  Os  pterygoideum. — Pterygoid  bone. 

O.  alsph.,  Os  alisphenoideum. — Aiisplienoid  bone. 

O.  pit.,  Os  palatinum.— Palate  bone  (Fig.  57). 

O.  orsph.,  Os  orbito-sphenoideum. 

O.  frontis.— Frontal  bone  (Fig.  56). 

§  548.  O.  vomeris,  az. — Vomer. — The  vomer  is  a  mesal  bone  forming  part  of  the 
septum  of  the  nasal  cavities. 

§  549.  O.  mesethmoideum,  az, — Vertical  plate  of  the  ethmoid. — This  is  a  mesal  bone 
forming  most  of  the  partition  between  the  nasal  cavities. 

O.  Nasale. — Nasal  bone. 

O.  mxtrb.,  Os  maxillo-turbinale — Maxillary  or  inferior  turbinated  bone. — It  is  a 
greatly  plicated  bone  occupying  the  ventral  p  ;it  of  the  nasal  cavity. 

§  550.  O.  ethtrb.,  Os  ethmo-turbinale — Ethmo-turbinal  bone. — This  is  also  a  greatly 
plicated  bone  ;  it  occupies  the  dorsal  and  greater  half  of  the  nasal  cavity.  It  projects 
caudad  into  both  the  frontal  and  the  sphenoidal  sinuses  (Fig.  GO). 

O.  pmx.,  Os  praemaxillare. — Praemaxillary  or  intermaxillary  bone  (Fig,  57). 

O.  mx.,  Os  maxillare — The  upper  jaw  bone. — In  this  figure  it  is  not  marked,  but  it 
is  the  deeply  shaded  part  just  caudad  of  the  0.  Prmx. 

Pre.  pel.,  Processus  postelinoideus,  az. — Posterior  clinoid  process. 

Pre.  prel,,  Processus  praeelinoideus,  az. — Praeclinoid  process. 

Sella,  Sella  turcica,  az. — This  is  a  space  or  pit  formed  by  the  two  clinoid  processes 
(Fig.  88). 

§  551.  S.  sph.,  Sinus  sphenoidalis — Sphenoidal  sinus. — This  is  a  space  in  the  prse- 
sphenoid  bone.  It  is  separated  from  its  platetrope  by  a  bony  partition.  It  is  lined  by  a 
continuation  of  the  nasal  mucous  membrane,  and  communicates  freely  with  the  nasal 
cavity. 

S.  frn.,  Sinus  frontalis.— Frontal  sinus  (Fig.  56,  60). 

§  552.  Tent.,  Tentorium. — The  osseous  tentorium  cerebelli  is  a  moderately  thick 
plate  of  bone  projecting  from  the  parietal  bones  into  the  cranial  cavity ;  it  separates  the 
cerebrum  from  the  cerebellum  (Fig.  88). 

Each  parietal  bone  furnishes  half  of  the  tentorium,  and  its  halves  are  conjoined  at  the 
meson  by  a  ventral  continuation  of  the  sagittal  suture  ;  (see  Fig.  88). 

§  553.  Fig.  60— Preparation. — The  skull  was  divested  of  its  soft 
parts  (§  250,  B).  It  was  then  sawed  obliquely  across  its  cephalic 
half  so  as  to  include  the  optic  foramina,  and  to  fully  expose  the 
frontal  sinuses.  The  left  lateral  wall  of  the  olfactory  fossa  was 
nipped  away,  and  likewise  the  lateral  projections  of  the  maxilla. 

Cn.  Ich,,  Canalis  lachrymalis.— Lachrymal  canal  (Fig.  56), 

Fm.  (Foramen)  opticum — Optic  foramen. — The  optic  chiasma  rests  in  the  groove 
between  the  two  foramina  (Fig.  114). 


188 


ANATOMICAL    TECHNOLOGY. 


Fm.  sphplt.,  Foramen  spheno-palatinum. — Sphenopalatine  foramen. 
Fm.  infor..  Foramen  infraorbitale. — Infraorbital  foramen. 

§  554.  Lm.  (Lamina)  cribrosa — Cribriform  plate  of  the  ethmoid. — The  mesethmoid 
separates  the  bones  of  the  two  sides.  The  cribriform  plate  is  the  cranial  part  of  the  eth- 
moid, the  ethmo-turbinals  properly  belonging  to  the  face. 

O.  praesph.,  Os  praesphenoideum,  az. — 
Praesphenoid  bone. 

O.  pit.,  Os  palatinum. — Palate  bone. 
O.    Ich.,     Os    lachrymale.  —  Lachrymal 
one  (Fig.  56). 
O.  planum  (Fig.  56). 

O.  ethtrb.,  Os  ethmo-turbinale — Eth 
mo-turbinal  bone. — In  this  figure  is  shown 
the  rounded  scroll-like  part  projecting  into 
the  frontal  sinus  (§  550). 

O.  frontis. — Frontal  bone. 

Sinus  frontalis. — Frontal  sinus  (Fig.  56). 


Zc?t« 


Am-tCrctro** 


OpUautti, 


Fig.  60.— Dorso-caudal  View  of  the 
Lamina  Cribrosa  and  the  Sinus 
Frontalis  :   x  1.5. 


§  555.  Fig.  61 — Preparation.— 
After  the  removal  of  the  soft  parts 
(§  250,  B),  the  rami  were  separated 
at  the  symphysis  menti  (Fig.  62). 


mandibularis. — 


mandibularis. — 


§  556.    An.    (Angulus) 
Mandibular  angle. 

Cd.    mndb.,    Condylus 
The  condyle  or  arthral  head  of  the  mandible  (Fig.  63>. 

D.  m.,  Dens  molaris. — Molar  tooth. 

DD.  pm.,  Denies  praemolares— Praemolar  teeth.— The  bicnspides  of  Anthropotomy. 

D.  c.  Dens  caninus. — Canine 
tooth. 

DD.  i.,  Denies  incisores.— 
Incisor  teeth. 

Fm.  m  ,  Foramen  meniale — 
Mental  or  labial  foramen. — There 
are  almost  invariably  two  on  each 
side  in  the  cat. 

Fs.  (Fossa)  coronoidea — Cor- 
onoid  fossa. — From  this  fossa  arises 
a  large  part  of  the  masseter  muscle. 

Pre.  cor.,  Processus  coronoi- 
deus. — Coronoid  process. 

§  557.  Ramus,  Ramus  mandibularis— Mandibular  ramus.— The  mandible  is  madi 
up  of  two  similar  bones  joined  at  the  symphysis  menti,  and  these  rami  form  the  fram€ 
work  of  the  floor  of  the  mouth  ;  Flower,  A,  120. 

In  Human  Anatomy,  the  "  ramus "  is  the  so  called  "  ascending  part,'*  and  not  th«l 
entire  half  of  the  mandible  as  here  ;  Quain,  A,  I,  54. 


Fig.  61 


-Lateral 

LAR  Ramus 


Mandibtj.j 


§  558. 


Fig. 


62- 


-Preparation.— All  the  soft  parts  were  remove 


DORSAD    ASPECT    OF    THE   MANDIBLE. 


189 


(^  250,  B) ;  while  still  moist  the  two  rami  were  slightly  separated 
at  the  symphysis  mentis  and  the  teeth  of  the  right  side  were 
extracted  with  the  nippers  to  show  the  alveoli,  as  in  Fig.  57. 


DD.  I/* 


Pig.  62.— Dorsal  View  op  the  Mandible.    (Modified  from  Straus-Durckheim).     x  1.75. 

§  559.    Alveoli. — These  are  the  cavities  in  which  the  teeth  are  implanted. 

§  560.  Cd.  (Condylus)  mandibularis — Mandibular  condyle  or  arthral  head. — This 
amooth  cylindrical  process  articulates  diarthrodially  with  the  Fossa  mandibularis  of  the 
temporal  (Fig.  57). 

D.  m.,  Dens  molaris. — Molar  tooth. 

DD.  pm.,  Denies  praemolares. — Praemolar  teeth. 

D.  c,  Dens  caninus. — Canine  tooth ;  Wilder.  15. 

DD.  i.,  Denies  incisores. — Incisor  teeth. 

Fm.  di.,  Foramen  dentale  inferior. — Inferior  dental  foramen. 

Margo  alveolaris — Alveolar  margin. — The  margin  or  border  of  the  jaw  in  which  the 
teeth  are  implanted. 

Pre.  (Processus)  coronoideus. — Coronoid  process. 

§  561.  Symphysis  menti. — The  symphysis  is  the  amphiarthrodial  articulation  be- 
tween the  two  rami.  It  is  indicated  in  the  figure  by  a  dark  line  just  to  the  left  of  the 
incisor  teeth.  In  old  cats  this  symphysis  often  becomes  anchylosed,  but  in  young  individ^ 
uals  considerable  motion  is  possible  between  the  two  rami. 


190 


ANATOMICAL    TECHNOLOGY, 


%  562.  Table  of  the  Foramina  and  Canals  of  the  Skull,  the  Bones 
enclosing  them,  and  the  Principal  Structures  to  which  they 
give  Passage. 

The  foramina  are  enumerated,  commencing  at  the  caudal  end  of  the  skull.  Fig.  56, 62. 
All  are  lateral  or  paired  except  the  foramen  magnum,  which  is  mesal. 


FORAMINA. 


Foramen  magnum 

Foramen  condylare 

Foramen  jugulare 

Foramen  stylo-mastoideum. . 
Meatus  auditorius  internus . . 

Aquaeductus  Fallopii 

Hiatus  Fallopii 

Meatus  auditorius  externus.. 

Foramen     lacerum     medium 
(§533) 

Canalis  Eustachiana 

Foramen  ovale 

Foramen  rotundum 

Foramen  lacerum  anterius. . . 

Foramen  opticum 

Foramina  olfactoria 

Foramen  palatinum  posterius 

Foramen  spheno-palatinum. . 

Foramen  palatinum  anterius. 
Foramen  orbitale 

Canalis  lachrymalis 

Foramen  infraorbitale 

Foramen  dentale  inferius 

Foramina  mentalia 


BONES  ENCLOSING 
THE  FORAMINA. 


Basi-  ex-  and  supra- 
occipitale 

Exoccipitale 

Basi-  and  ex-ccipi- 
tale,  tympanicum 
and  pars  petrosa . . 

Tympanicum,  pars  ) 
mastoidea ) 

Pars  petrosa 

Pars  petrosa,  pars 
mastoidea,  tym 
panicum 

Pars  petrosa 

Tympanicum . . , 

Pars  petrosa,  basi-  \ 

sphenoideum  .  . .  \ 

j  Alisphenoideum,  bul 

\      la  tympanica 

Alisphenoideum 

Alisphenoideum 


j  Ali-  and  orbito-sphe- 
\     noideum 

Orbito-sphenoid^m . 

Lamina  cribrosa 

Palatinum 

Palatinum 

j  Maxillare,pr8emax-  \ 
\      illare.    .  .    S 

Palatinum,  maxillare 
(Lachrymale,   max-  J 
•<     illare,     maxillo-  V 
(     turbinale ) 

Maxillare 

Mandibula 

Mandibula 


STRUCTURES  THAT  TRAV- 
ERSE THE  FORAMINA. 


j  Myelon,  N.  (spinalis)  accessorius 
(      (XI),  A.  basilaris. 
N.  hypoglossus  (XII). 
N.  vagus  (X),  N.  (s|)inalis)  acces- 
sorius (XIj,  N,  glosso-pharyn- 
geus  (IX),  Vena  jugularis. 

N.  facialis  (VII). 

N.  auditorius  internus  (VIII),  N. 
facialis  (VII),  A.  auditoria  in- 
terna. 

N.  facialis  (VII). 

N.  petrosalis  superficialis  (ec-' 
talis),  (branch  of  Vidian). 

Admits  air  to  the  membrana 
tym  pan  i. 

Arteria  carotidea  interna, 

jTuba  Eustachiana,  A.  carotidea 
\      interna  (§  533). 
(N.   maxillaris  inferior  (od  divi- 
-<      sion  of  V) ;   stiiall  meningeal 
(     artery. 

^^N.    maxillaris    superior   (2d    or 
\     middle  division  of  V). 
''N.  ophthalmicus  (1st  division  of 
V),  N.  oculomotorius  (III),  N, 
abducens  (VI),  N.  troclilearis 
(IV),  A.carotidea  externa  (large 
branch  from  the  rete  mi ra bile). 
N.  opticus  (11) ;  a  meningeal  ar- 
tery. 
NN.  olfactorii. 
NN.  palatini,  A  A.  palatinae. 
NN.  spheno-palatini,  AA.  sphe- 
no-palatinae. 

N.  naso-palatinus,  A.  nasalis. 

N.  oculo-nasalis,  A.  ethmoidalis. 

Ductus  lachrymalis. 

N.  in fraorbi talis.  A. infraorbital! s. 
\  N.  dentalis  inferior,  A.  et  V. 
i      dentales  inferiores. 

N.  mentalis,  A.  mentalis. 


THE    STRUCTURE    OF   BONE.  191 

§  563.  The  capacity  of  a  prepared  skull  may  be  obtained  by  filling  it  througli  tbe 
Fin.  magnum  with  sand  or  fine  shot,  and  then  pouring  the  material  into  a  graduate  glass. 
If  tlie  material  used  in  determining  the  capacity  is  fine  enough  to  pass  through  the  fora- 
mina, they  must  be  plugged  in  some  way. 

The  weight  of  the  brain  may  be  obtained  approximately  by  reckoning  the  cubic  centi- 
meters of  capacity  as  grams  and  adding  4  per  cent.  (Wyman,  70).  Thus,  if  a  cat's  skull 
lias  a  capacity  of  2o  cc,  the  brain  of  the  same  cat  would  weigh  approximately  26  grams. 
VVyman's  statement  refers  only  to  the  human  brain,  but  presumably  the  specific  gravity  of 
the  cat's  brain  is  nearly  or  quite  identical  with  that  of  man. 

§  5G5.  Obvious  Structure  of  Bone. — In  life  the  surface  is  covered  with  a  dense  layer 
of  connective  tissue,  the  periosteum.  Entad  of  this  periosteum  is  a  layer  of  compact  bone. 
The  intermediate  part  of  all  bones  is,  however,  more  or  less  loose  in  structure,  something 
like  a  sponge,  hence  it  is  called  spongy  or  cancellated  bone.  This  is  especially  abundant 
toward  the  end  of  long  bones  and  in  the  vertebral  centra. 

§  5C6.  Microscopic  Structure. — A  solid  mass  containing  :  A.  Haversian  canals,  cyl- 
indrical channels  shown  as  circles  in  cross  section,  as  cylinders  in  longitudinal  sections 
of  long  bones.  These  canals  contain  the  blood  vessels,  as  may  be  demonstrated  by  exam- 
ining a  finely  injected  cat's  scapula  (see  Frey,  A).  They  anastomose  freely,  and  open 
either  upon  the  ectal  surface  or  within  the  medullary  canal. 

B.  Lacuiim  and  canaliculi.  These  are  the  spaces  occupied  by  the  protoplasmic  bone 
cells  or  corpuscles  and  their  prolongations.  They  appear  in  outline  like  irregularly 
fusiform  connective  tissue  corpuscles  with  many  fine  prolongations  or  branches.  These 
branches  anastomose  with  the  branches  of  neighboring  lacunsB,  and  sometimes  open  into 
an  Haversian  canal. 

In  transections  of  long  bones  the  solid  matter  and  lacunae  are  seen  to  be  arranged  in 
more  or  less  concentric  lamellae  around  the  Haversian  canals. 


CHAPTEK    VI. 

MYOLOGY— THE  STUDY  OF  THE  MUSCLES. 

GENERAL  CONSIDERATIONS— FREQUENCY  OP  MUSCULAR  VARIATIONS— EXPLANATION  OP 
TECHNICAL  TERMS— APHORISMS  FOR  DISSECTORS— LIST  OP  INSTRUMENTS  AND 
MATERIALS — HOW  TO  USE  DISSECTING  INSTRUMENTS — PRACTICAL  SUGGESTIONS — 
CLIPPING  THE  HAIR— CUTTING  THE  SKIN— REMOVAL  OP  THE  SKIN— NAMES  AND 
SYNONYMS  OP  THE  MUSCLES  HEREIN  DESCRIBED — DESCRIPTIONS  OP  FORTY  MUSCLES 
OP  THE  CEPHALIC  REGION  OP  THE  BODY,  WITH  DIRECTIONS  FOR  THEIR  DISSEC- 
TION—THE STRUCTURE  OF  MUSCLE. 

General  References  to  Myotomy.— Bernard,  A,  182-206  ;  Chauveau  (Fleming?),  184- 
186  ;  Cleland,  A,  1-7  ;  Heath  (Keen),  A,  Appendix  ;  Hodges,  A  ;  Hyrtl,  A,  59-67  ;  Mojsis- 
ovics,  A,  1-15;  Straus-Durckheim,  B,  130-162;  Reeves,  A. 

§  567.  Muscular  Homologies. — The  following  works  and  papers  deal  with  the  general 
and  special  homologies  of  muscles  ;  the  first  three  embrace  all  Vertebrates  and  all  regions 
of  the  body;  the  others  refer  mainly  to  the  limbs  of  the  Mammalia:  Humphrey,  E, 
105-188 ;  Meckel,  A,  V,  VI ;  Cuvler,  A,  I  ;  Quain,  A,  I,  185 ;  Mivart,  4  ;  Macallister,  9, 
12,  19  ;  Rolleston,  13 ;  Krause,  A  ;  Coues,  1,  36,  47  ;  Wilder,  1,  4,  lO,  20. 

§  568.  General  Considerations. — For  the  reasons  stated  in  §  204,  Practical  Anatomy 
always  begins  with  the  skeleton,  including  the  bones  and  cartilages,  the  arthra  (joints) 
and  ligaments. 

Of  the  soft  parts,  the  muscles  are  most  easily  prepared,  examined  and  preserved,  and 
they  serve,  together  with  the  bones,  as  landmarks  for  the  recognition  of  the  vessels  and 
nerves ;  hence  Myology  naturally  succeeds  Osteology. 

Yet  the  practical  study  of  the  muscles  is  not  without  its  difficulties. 

Upon  the  limbs,  excepting  the  distal  segments,  the  muscles  are  much  more  numerous 
than  the  bones.  For  example,  in  the  arm  and  shoulder  girdle,  if  we  omit  the  manus, 
there  are  jive  bones,  scapula,  clavicle,  humerus,  ulna  and  radius.  Excluding  those  which 
arise  from  the  humerus  and  are  inserted  upon  the  manus,  more  than  thirty  distinct 
muscles  are  attached  to  these  five  bones. 

The  larger  bones  also  are  readily  recognized,  even  when  covered  by  soft  parts  ;  but  two 
or  more  muscles  in  the  same  locality  may  have  the  same  general  form  and  direction,  so 
that  their  determination  may  involve  a  careful  examination  of  their  attachments. 

Hence,  whereas  most  of  the  bones  may  be  prepared  in  the  same  way,  the  general  rules 
for  dissection  must  be  modified  and  supplemented  with  respect  to  each  muscle,  in  order 
that  it  may  be  exposed,  dissected,  examined  and  removed  to  the  best  advantage. 

§  569.  Just  how  explicit  the  directions  should  be  has  not,  apparently,  been  fully 
determined  by  anatomical  teachers  and  wri::ers.     Some  "Laboratory  Directions "  are  so 


I 


MUSCULAR     VARIATION,  193 

meager  as  to  be,  according  to  our  experience,  of  no  value  whatsoever.  Nowhere,  in 
zootomical  works,  have  we  found  them  so  complete  as  in  the  "  Dissector's  Guides  "  which 
are  used  in  the  Medical  Schools.  Yet  even  these,  in  our  opinion,  are  not  altogether 
suited  to  the  needs  of  the  beginner.  They  are  not  suflBciently  full ;  all  the  parts  in  a 
given  region  are  considered  at  once,  a  plan  better  adapted  to  the  advanced  student ;  finally, 
too  little  attention  is  given  to  typographical  and  paragraphic  details  which  might  facili- 
tate the  recognition  of  statements  and  reference  to  other  parts  of  the  work. 

Without  assuming  to  have  decided  correctly  in  this  matter,  we  have  acted  upon  the 
belief  that  dissection  is  a  fine  art,  and  by  no  means  easy  to  acquire  ;  that  the  beginner  is 
liable  to  fall  into  grave  errors  as  to  manipulation,  fact  and  interpretation  ;  and  that,  upon 
the  whole,  it  is  better  for  him  to  follow  even  an  imperfect  method  than  none  at  all. 

§  570.  Variation, — Another  diflBculty  met  with  in  the  study  of  muscles  is  the  frequency 
of  variations  and  anomalies  not  only  as  to  size  and  shape,  but  also  as  to  connections,  vas- 
cular and  nervous  supply,  and  even  presence. 

All  standard  works  upon  Human  Anatomy  record  the  existence  of  such  variations,  and 
it  is  probable  that  the  careful  examination  of  any  human  subject  would  disclose  one  or 
more  departures  from  the  condition  regarded  as  normal. 

Notwithstanding  the  intrinsic  probability  that  any  other  Mammals,  at  least  the  domes- 
ticated species,  would  vary  in  a  similar  manner,  most  dissectors  of  the  lower  animals  seem 
to  have  assumed  that  what  is  true  of  one  individual  is  true  of  the  w  hole  species,  and  the 
myological  descriptions  of  Straus-Durckheim  (A),  Chauveau  (A),  Coues  (47),  and  Krause 
(A)  rarely  mention  departures  from  rule.  Yet  no  two  anthropoid  apes  have  been  found  to 
agree  in  all  respects,  as  may  appear  from  the  published  dissections  of  Duvernoy  (lOO), 
Humphrey  (lO),  Champneys  (1),  Wyman  (47),  Macalister  (151,  41),  Barnard  (i),  the 
senior  author  (1)  and  others,  and  Huxley  has  distinctly  expressed  (A,  410)  the  belief  that 
"  endless  varieties  will  no  doubt  be  met  with  by  those  who  carry  their  inquiries  farther" 
than  by  the  dissection  of  single  individuals  of  a  species ;  see  also  the  remark  of  Galton, 
1,  175,  note  30. 

The  senior  author  has  remarked  upon  the  existence  of  individual  variations  among 
domesticated  dogs  (21,  308),  and  we  may  add  that  no  one  of  the  scores  of  cats  dissected 
by  us  or  our  students  has  failed  to  present  some  peculiarity  of  muscular  arrangement. 

The  records  of  these  variations  have  not  as  yet  been  put  into  shape  for  publication,  and 
in  the  present  descriptions  it  has  seemed  better  to  give,  in  most  cases,  only  what  seems  to 
be  the  most  usual  structure.  The  student  is  reminded,  however,  that  his  very  first  dis- 
section may  disclose  some  feature  hitherto  unobserved, 

§  571.  Errors  of  Manipulation. — The  beginner  should  bear  in  mind  that  nothing  is 
more  easy  than  to  commit  some  error  of  manipulation — whether  by  a  cut  too  many  or  a 
cut  too  few — which  may  greatly  affect  the  appearance  of  the  parts,  and  lead  to  very  mis- 
taken conclusions.  As  a  rule,  therefore,  supposed  anomalies  should  not  be  published  until 
submitted  to  competent  criticism,  or  carefully  checked  by  the  dissection  of  other  individ- 
uals, or  still  better  of  the  other  half  of  the  same. 

In  all  cases,  the  student  will  do  well  to  recall  the  advice  of  Cuvier  to  a  young  medical 
student  who  ventured  to  tell  him  that  he  had  discovered  something  very  new  and  remark- 
able in  a  human  body.  Cuvier  replied  :  "  Go  and  anatomize  an  insect,  the  largest  you  can 
find  ;  then  reconsider  your  observation,  and  if  it  appear  to  be  correct,  I  will  believe  you 
on  your  word."  After  making  the  dissection,  the  student  confessed  that  he  had  been  in 
error  ;  (Lee,  A,  5G). 

As  has  been  suggested  by  the  senior  author  (22,  307),  it  is  doubtful  whether  any  dis- 
section by  beginners  should  be  published  at  all,  excepting  upon  the  approval  of  an  experi- 
enced anatomist,  after  thorough  examination. 
13 


194  ANATOIIICAL   TECHNOLOGY. 

§  572.  Errors  of  Interpretation.— IVhen  an  author  denies  the  existence  of  a  part  tho 
presence  of  which  is  affirmed  by  other  writers,  the  discrepancy  may  be  due  to  either  of 
five  causes  : — 

1.  Its  absence  is  the  rule,  and  its  presence  in  the  other  cases  was  exceptionaL 

2-  It  was  absent,  though  normally  present. 

3.  It  was  present,  but  accidentally  overlooked. 

4.  It  was  observed  but  not  recognized,  or  was  mistaken  for  some  other  part. 

5.  It  was  seen,  but  purposely  ignored. 

Of  course  the  last  named  explanation  is  also  the  last  to  be  entertained,  but  either  of  the 
other  four  contingencies  is  liable  to  occur  with  even  experienced  dissectors  and  learned 
anatomists. 

For  example,  the  M.  entopectoralis  (Fig.  73),  ** pectoralls  minor,"  is  said  by  Straus-Durck- 
heim  (A,  II,  336),  and  implied  by  Meckel  (A,  VI,  249),  and  Mivart  (B,  145),  to  be  wanting 
with  the  cat ;  its  existence  in  any  Carnivora  is  also  denied  by  Cuvier  (A,  I,  370),  and  A.  H. 
Young  (1, 171).  Owen,  however,  speaks  (A,  III,  50),  of  the  "  pectoralis  minor  of  the  dog," 
and  its  presence  in  that  animal  is  admitted  by  Haughton  (115)  and  Wood  (7,  52),  as  it 's 
in  the  cat  by  the  senior  author,  who  refers  (20,  303)  to  it  as  found  in  all  the  Felidae  and 
Canidae  examined  by  him. 

The  muscle  considered  by  the  writers  last  named  to  represent  the  "  pcctoralis  minor  '* 
of  man  is  so  large  in  most  Carnivora  that  it  was  not  recognized  by  the  five  writers  first 
named  as  the  representative  of  that  rather  insignificant  muscle  ;  in  the  bear  and  skunk, 
however,  as  stated  by  the  senior  author  in  the  paper  referred  to,  it  is  again  smaller  than 
the  M.  ectopectoralis. 

In  illustration  of  the  second  case,  the  M.  supinator  longus  (Fig.  74)  is  said  by  Meckel 
(A,  VI,  303),  and  Huxley  (A,  355)  to  be  wanting  with  the  dog.  Chauveau,  however, 
affirms  (A,  290)  its  presence  in  dogs  of  all  breeds,  and  it  has  been  repeatedly  observed  by 
the  senior  author.  Hence  we  may  conclude,  provisionally  at  least,  that  it  was  exception- 
ally absent  in  the  individuals  dissected  by  Meckel  and  Huxley. 

THE  TECHNICAL  TERMS  OF  MYOLOGY. 

§  573.  Musculus — Muscle. — The  name  for  a  mass  of  muscular 
fibers.     Such  a  muscle  may  or  may  not  be  a  true  muscular  integer. 

What  constitutes  a  muscular  integer  has  not  been  determined  ;  as  stated  in  the  senior 
author's  brief  discussion  of  the  subject  (lO,  63),  the  phrase  "morphological  integer" 
seems  to  have  been  first  used  with  reference  to  the  muscles  by  Coues  (i,  223),  but  the  gen- 
eral question  is  discussed,  directly  or  indirectly,  by  Owen,  Parker,  Spencer,  and  more 
recently,  Humphrey  (E).  In  the  present  work,  it  has  seemed  best  to  us  to  recognize  as 
separate  muscles,  or  as  distinct  divisions  of  muscles,  all  the  muscular  masses  whose  origins 
and  insertions  me  fairly  constant  and  capable  of  definite  description. 

In  applying  separate  names  to  the  divisions  of  the  human  trapezius  (Fig.  6G,  §  607), 
and  deltoidevs  (Fig.  QQ,  §  G74),  and  yet  treating  the  long  and  short  heads  of  the  coracoideus 
(Fig.  75,  §  668),  as  a  single  muscle,  we  are  certainly  open  to  the  charge  of  inconsistency. 
In  the  present  transitional  state  of  opinion  respecting  muscular  integers,  entire  consis- 
tency is  hardly  to  be  expected. 

§  574.  Muscular  Groups. — It  is  sometimes  conveident  to  speak 
of  two  or  more  muscles  collectively  as  a  group,  as,  e,  g.^  the  pecto- 
ralis  group,  the  trapezius  group,  the  triceps  group. 


PARTS    OF   A    MUSCLE,  195 

§  575.  Subdivisions. — As  has  been  well  stated  by  Humphrey 
(E,  110),  the  longitudinal  subdivision  of  a  muscle  may  be  either 
vertical  or  TiorizontaL  For  the  sake  of  distinctness,  we  shall  call 
the  subdivisions  of  tlie  former  kind  dimsiones^  and  those  of  the  lat- 
ter lamince.  For  example,  as  has  been  remarked  by  the  senior 
author  (20,  306),  the  ' '  M.  ectopectoralis  (Fig.  72)  tends  to  separate 
into  superimposed  laminae,  while  the  entopectoralis  tends  to  form 
fasciculi."  In  the  former  the  "  cleavage"  is  horizontal,  in  the  lat- 
ter vertical. 

§  576.  Parts  of  a  Muscle. — The  essential  and  usually  largest 
portion  of  a  muscle  is  the  mass  of  muscular  fibers  ;  this  is  called  its 
body  or  belly. 

Sometimes  one — rarely  if  ever  both — of  the  ends  of  a  muscle  is 
attached  to  bone  directly  or  rather  to  its  periosteum.  This  is  the 
case  with  the  humeral  end  of  the  M.  hracMalis  (Fig.  74,  §  692),  and 
the  M.  entotriceps^  div,  intermedia  (Fig.  75,  §  686). 

More  often,  however,  there  intervenes  between  the  muscular  por- 
tion and  the  bone  a  cord  or  sheet  of  white  inelastic  fibrous  tissue, 
constituting  the  tendon.  The  attachment  is  then  said  to  be  tendi- 
nous^ while  in  the  former  case  it  was  muscular. 

Tendons  maybe  so  short  as  to  be  hardly  distinguishable,  like 
the  coracoid  tendon  of  the  M.  coracoideus  (§  668),  or  they  may  be 
longer  than  the  muscular  portion,  like  the  humeral  tendon  of  the 
same  muscle  (Fig.  75). 

Sometimes,  especially  with  thin  flat  muscles  like  the  laminse  of 
the  M.  ectopectoralis  (Fig.  72),  the  tendinous  sheet  may  be  so  short 
as  to  be  practically  absent. 

§  577.  Attachment  Lines  and  Areas. — Muscular  attachments 
usually,  and  tendinous  attachments  sometimes,  cover  considerable 
areas  {bracJiialis^  Fig.  68) ;  in  other  cases  the  attachment  is  along 
lines  {entopectoralis^  divisio  caudalis,  Fig.  69). 

§  578.  Origin  and  Insertion. — Of  the  two  attachments  of  a  mus- 
cle, one  is  called  origin  and  the  other  insertion.  Usually,  but  not 
always,  the  origin  is  from  the  more  fixed  part  of  the  body,  and  the 
insertion  is  upon  the  more  movable  part. 

§  579.  Choice  of  Origin  and  Insertion. — With  the  membral 
muscles,  one  attachment  is  generally  nearer  the  soma  (§  54)  or  the 
proximal  end  of  the  limb,  and  this  attachment  is  always  called  the 
origin.  Thus  the  scapular  attachments  of  the  MM.  biceps  (Fig.  75) 
and  subscapularis  (Fig.  73)  are  the  origins  of  those  muscles ;  so 


196  ANATOMICAL    TECHNOLOGY. 

also,  the  origins  of  the  MM.  entopectoralis  (Fig.  72)  and  clavo- 
trapezius  (Fig.  66)  are,  respectively,  their  sternal  and  vertebral 
attachments. 

But  the  question  is  less  easy  with  some  muscles  which  connect  different  parts  of  the 
soma  with  each  other,  or  which  extend  between  the  head  and  the  scapula,  clavicle  or 
sternum. 

Without  feeling-  sure  as  to  what  is  best,  we  have  adopted  the  following  basis  : — 

As  between  the  head  and  the  neck  or  the  trunk,  the  latter  are  more  central  and  afford 
origin  to  the  muscles  of  the  head. 

The  sternum  is  part  of  the  trunk,  and  sternal  attachments  are  therefore  origins. 

The  scapula  and  clavicle  appertain  to  the  arm  rather  than  to  the  trunk,  and  attachments 
thereto,  as  compared  with  attachments  to  the  head  or  neck  or  trunk,  are  insertions. 

It  will  be  seen  that  the  acceptance  of  these  rules  entails  some  a])parent  contradictions : 
For  example,  the  daw-mastoideus  (Fig.  67),  like  the  clavo-trapezius  (Fig.  66),  arises 
from  the  skull  and  is  inserted  upon  the  clavicle ;  but  the  aterno-mastoideus  (Fig.  67), 
like  the  spleniua  (Fig.  67),  arises  from  the  trunk  and  is  inserted  upon  the  skull. 

Hence  the  origin  of  the  clavo-mastoideus  practically  coincides  with  the  insertion  of 
the  sterno-mafttoideus.  In  man,  where  the  clavicle  joins  the  sternum,  the  two  muscles 
are  commonly  described  as  one,  under  the  name  of  sterno-cleido-inastoideus,  and  one 
part  of  the  muscle  therefore  arises  where  the  other  is  inserted,  and  vice  versa. 

§  580.  TTie  Determination  of  Muscular  Homologies. — Of  course 
the  function  of  a  muscle  depends  upon  its  insertion,  but  there  is 
considerable  difference  of  opinion  as  to  whether  the  origin  or  the 
insertion  is  the  better  guide  to  the  determination  of  its  homology. 
We  are  disposed  to  assign  greater  morphical  importance  to  the  ori- 
gin, according  to  the  views  of  Barnard  (i,  114).  As  to  the  value  of 
vascular  and  nervous  supply,  see  Cunningham  {1)  and  Gadow  {3). 

%  581.  Fascia. — This  is  simply  a  thin  sheet  of  the  same  kind  of 
fibers  as  the  tendon,  but  the  fibers  may  present  two  kinds  of  ar- 
rangement. Sometimes  the  tendon  itself  is  so  thin  as  to  be  called  a 
fascia,  or  it  may  be  continued  as  a  thin  sheet  upon  one  or  the  other 
face  of  the  muscle ;  in  both  these  cases,  the  fibers  are  nearly  or  quite 
parallel.  The  n2imQ fascia,  however,  is  more  often  given  to  a  sheet 
of  fibers  crossing  one  another  in  various  directions,  and  forming  a 
sheath  or  covering  for  a  muscle  or  a  group  of  muscles.  A  fascia  is 
also  called  an  aponeurosis,  but  the  name  is  objectionable  on  account 
of  both  length  and  etymology. 

§  582.  Forms  of  Muscles.— The  body  of  a  muscle  may  he  fusi- 
form or  spinMe-sJiaped,  like  that  of  the  M.  biceps  (Fig.  73) ;  tceni- 
ate  {strap-shaped  or  rihbon-lilce\  as  with  the  occipito- scapular  is 
(Fig.  67) ;  fan-shaped  like  the  subscapularis  (Fig.  73) ;  quad/ri- 


APHORISMS    FOR    DISSECTORS.  197 

lateral  like  the  acromio-trapezius^  or  triangular  like  the  spino-tra- 
vezius  (Fig.  ^Q).  There  are  other  and  less  usual  forms  which  will 
be  indicated  in  special  cases. 

§  583.  Designation  of  the  Borders  of  Muscles. — Many  of  the 
muscles  are  thin  and  triangular  or  tseniate,  so  as  to  present  sharply 
defined  harder s^  in  place  of  the  more  or  less  rounded  aspects  or  sur- 
faces of  a  fusiform  muscle  like  the  biceps. 

Such  a  flat  muscle  may  become  twisted  upon  its  axis  in  such  a 
way  as  to  change  the  relations  of  the  borders  to  the  body-planes. 
In  these  cases,  for  the  sake  of  convenience,  it  will  be  considered  that 
the  muscle  has  the  general  direction  which  it  had  at  its  origin,  al- 
though this  may  sometimes  involve  an  apparent  contradiction  of  the 
terms  in  which  the  insertion  is  described. 

For  example,  the  M.  pecto-antehracMalis^  dv.  cephalica  (Fig. 
72),  arises  at  the  meson,  and  its  borders  are  called  cephalic  and 
caudal  throughout  its  whole  length,  notwithstanding  the  fact  that 
the  line  of  insertion  upon  the  ulna  has  a  proximo-distal  direction,  so 
that,  as  based  thereon,  the  borders  would  be  proximal  and  distal. 

§  584.  Connect. — For  the  exposure  of  the  ectal  layer  of  muscles, 
certain  areas  of  skin  must  be  lifted.  The  lines  of  incision  which 
circumscribe  such  areas  are  said  to  ^'  connect "  certain  parts  or 
points,  usually  some  of  the  '^landmarks"  elsewhere  (§§  225-233) 
enumerated. 

§  585.  Girdle. — When  the  skin,  especially  of  a  limb,  is  divided 
by  an  incision  encircling  the  part,  the  latter  is  said  to  be  ''girdled." 

§  586.  Transect. — In  order  to  examine  fully  the  attachments  of 
a  muscle,  it  is  usually  desirable  to  divide  it  transversely  and  reflect 
the  two  ends  in  opposite  directions.  For  the  sake  of  brevity,  this 
entire  operation  will  be  indicated  by  the  use  of  the  single  word 
transect. 

APHORISMS  FOR  DISSECTORS. 

§  587.  1.  •'  Without  skilful  manipulation  we  can  neither  teach 
by  demonstration  facts  which  have  been  already  discovered,  nor 
hope  to  extend  the  limits  of  observation  and  experimental  knowl- 
edge."—L.  S.  Beale,  A. 

3.  "A  piece  of  true  dissection  ought  to  turn  out  an  object  of 
wonder  and  beauty." — Goodsir,  A,  I,  24. 

3.  "•  An  anatomist  therefore  in  these  curious  things  had  need  to 
have  a  fine  and  dainty  hand,  and  at  command." — Crooke,  A,  460. 


198  ANATOMICAL    TECHNOLOGY. 

4.  ''The  best  workman  uses  the  best  tools." — Owen. 

5.  The  value  of  instruments  depends  not  upon  their  handles, 
their  finish  or  their  cost,  but  upon  the  adaptation  of  their  size,  form 
and  temper  to  the  work  in  hand. 

6.  Fingers  are  often  the  best  forceps. 

7.  Handling  and  cutting  are  necessary  evils. 

8.  J^eglect  of  the  knife  may  leave  the  truth  concealed  ;  its  misuse 
may  establish  an  error. 

9.  ''Let  the  eye  go  before  the  hand,  and  the  mind  before  the 
eye." — O.  W.  Holmes. 

10.  Fat  is  the  anatomist' s  worst  enemy. 

11.  "  Drying  is  even  worse  than  decomposing."— K.  M.  Hodges. 

12.  The  skin  makes  the  best  wrapper. 

13.  There  are  two  sides,  but  only  one  meson. 

14.  The  bones  are  the  guides  to  the  muscles,  the  muscles  to  the 
vessels,  and  the  vessels  to  the  nerves. 

15.  The  attachments  of  a  muscle  determine  its  homology  and 
function  ;  the  thickness  and  length  of  its  body  indicate  respectively 
its  power  and  the  distance  through  which  it  may  contract. 

16.  The  attachments  of  a  muscle  are  often  closely  associated 
with  those  of  others,  but  its  body  is  usually  distinct. 

17.  In  dissecting  muscles,  the  science  consists  in  discriminating 
between  fascia  or  tendon  and  mere  connective  tissue ;  the  art,  in 
removing  the  latter  so  as  to  leave  the  muscles  distinct. 

18.  Dissection  according  to  direction  favors  the  acquisition  of 
methods  and  the  learning  of  names  and  specified  relations  ;  but  the 
knowledge  of  parts  is  not  complete  until  the}^  liave  been  approached 
and  examined  from  all  sides.     See  also  §  122. 

§  588.   List  of  Instruments  and  Materials  for  the  Dissection 

of  Muscles.— Arthrotome,  Fig.  16,  §  135;  blocks,  §  137;  coarse 
forceps,  Fig.  18,  145  ;  fine  forceps,  Fig.  20,  §  146  ;  scalpels,  medium 
and  Charriere,  Fig.  23,  24,  §  155 ;  coarse  scissors,  curved  flatwise. 
Fig.  25,  §  156  ;  hair  scissors,  §  158;  towels,  §  165  ;  sharp  tracer.  Fig. 
17,  §  166 ;  tray,  §  167 ;  waste  pail,  §  195  ;  waste  papers,  §  172 ; 
wetting  bottle,  Fig.  27,  §  170. 

§  589.  TTie  Material  for  Dissection.— A  lean  animal  should  be 
preferred  ;  it  should  be  divided  by  abdominal  transection  (§  234) ; 
injected  with  alcohol  (§  285),  but  not — for  the  first  dissection— with 
plaster  ;  kept  in  42-55  per  cent,  alcohol  (§  286),  and  not  allowed  to  dry. 


USE    OF    THE    SCALPEL. 


199 


HOW   TO  USE  DISSECTING  INSTRUMENTS. 

§  590.  Hyrtl  complains  (A,  62)  that  ''  some  people  hold  the  for- 
ceps like  fire-tongs,  and  the  scalpel  like  a  cheese-knife."  It  is  true 
that  most  anatomical  instruments  are  for  either  grasping  or  cutting, 
but  their  proper  and  successful  employment  demands  much  more 
care  and  delicacy  than  is  needed  in  ordinary  household  operations. 
The  good  whittler  is  not  necessarily  an  expert  dissector,  and  even 
the  coarse  scissors  are  to  be  handled  very  differently  from  shears. 

The  anatomist,  like  the  surgeon — who  is  an  anatomist  and  some- 
thing more, — should  have  such  command  over  his  muscles  and 
nerves  that  whatever  instrument  is  in  his  hands  becomes  for  the 
time  being  like  a  part  of  himself,  an  extension  of  his  fingers,  sharper, 
firmer  and  more  slender,  yet  almost  equally  mobile  and  sensitive. 


Fig.  63.— The  Scalpel  Held  as  a  Pen.    (From  Bernard). 


§  591.  Use  of  the  Scalpel  (§  155).— The  scalpel  may  be  held  in 
either  of  three  general  ways  : — 

A.  LiJce  a  Pen  (Fig.  68). — The  edge  is  directed  backward  and 
downward,  or  forward  and  upward.    This  is  for  ordinary  dissection. 

B.  Like  a  Carmng-Tcmfe  (Fig.  64). — The  edge  may  be  directed 
upward  or  downward.  This  is  for  the  division  of  more  resisting 
tissues. 

C.  LiJce  a  Violin-bow  (Fig.  65). — The  scalpel  is  held  between  the 
tip  of  the  pollex  on  one  side  and  the  tips  of  the  other  digits  upon  the 


200 


ANATOMICAL    TECHNOLOGY. 


other.     This  is  for  long  sweeping  strokes,  where  the  greatest  freedom 
is  desired. 

Minor  modifications  of  these  three  ways  will  be  readily  adopted 
as  the  dissector  becomes  familiar  with  the  instrument. 


Fig.  64. — The  Scalpel  Held  as  a  Carving-knipe.     (From  Bernard). 

§  592.  Use  of  the  Scissors  (§  156).— Contrary  to  the  more  usnal 
custom,  dissecting  scissors  should  be  held  wath  the  pollex  and  me- 
dms.    The  index  then  serves  both  to  steady  the  instrument  and  to 


Fig.  65. — The  Scalpel  Held  as  a  Violin-bow.    (From  Bernard). 

aid  the  medius  in  its  opposition  to  the  more  powerful  pollex.  In 
nearly  all  cases  the  points  of  curved  scissors  should  be  turned  upward 
and  away  from  the  part  under  dissection.    This  precaution  is  es- 


THE    USE    OF   INSTRUMENTS.  201 

pecially  needful  in  the  trimming  of  vessels  and  nerves  and  inflated 
hollow  viscera  (§  331). 

§  593.  Use  of  the  Forceps  (§  145). — The  forceps  are  commonly 
held  between  the  pollex  and  the  index.  In  long  continued  dissec- 
tions the  medius  may  be  substituted  for  the  index  at  intervals.  The 
digits  should  be  employed  in  place  of  the  forceps  when  practicable, 
both  as  a  relief  from  fatigue  and  to  avoid  crushing  the  tissues. 

The  forceps  should  be  used  upon  muscles  as  little  as  possible, 
and  vessels  and  nerves  should  be  grasped  by  their  sheath  of  con- 
nective tissue.  For  the  separation  of  slender  muscles  and  of  vessels 
and  nerves,  the  safest  way  sometimes  is  to  insert  the  tip  of  the  closed 
forceps  and  then  allow  the  blades  to  separate  gently. 

§  594.  Use  of  the  Tracer  (§  166).— The  tracer  is  to  be  held  like 
a  pen  or  pencil.  Its  form  permits  a  rotation  on  its  axis,  so  that  the 
point  may  have  any  desired  direction. 

The  tracer  should  be  more  constantly  in  the  hand  than  any  other 
instrument.  Scalpels  and  other  sharp  instruments  should  only  be 
used  when  the  tracer  will  not  answer  the  purpose. 

The  tracer  is  also  very  useful  in  detecting  the  position  of  con- 
cealed hard  parts,  as  ribs,  cartilages  and  vertebrae.  The  point  may 
be  introduced  deeply  without  impairing  the  condition  of  the  parts  for 
dissection,  and  the  curvature  enables  one  to  lift  upon  it  the  ribs  or 
cartilages  so  as  to  coant  them  more  accurately. 

§  595.  Use  of  the  Arthrotome  (§  135). — As  its  name  implies, 
the  distinctive  use  of  this  instrument  is  for  the  division  of  joints  and 
other  rough  operations  which  might  injure  the  more  delicate  edge 
of  the  scalpels.  Yet  the  student  should  accustom  himself  to  accu- 
rate and  careful  manipulation,  and  endeavor  to  separate  the  contig- 
uous bones  at  an  arthron  without  injuring  the  cartilages.  He 
should  try  to  feel  with  the  point  of  the  instrument. 

PRACTICAL  SUGGESTIONS  FOR  DISSECTORS. 


1.  Select  a  lean  animal  for  all  anatomical  purposes,  and 
especially  for  the  dissection  of  the  muscles,  vessels  and  nerves.  The 
directions  for  killing  are  given  in  §  192. 

2.  Take  the  precautions  for  cleanliness  which  are  described  in 
§  199. 

3.  Remove  superfluous  parts  of  the  animal,  the  tail  in  some  cases 
(§  243),  the  caudal  or  cephalic  region  of  the  body,  according  to  the 


802  AI^  ATOMIC AL    TECHNOLOGY. 

directions  for  abdominal  and  thoracic  transection  which  are  given 
in  §§  287,  242. 

4.  See  that  all  the  instruments,  materials  and  books  for  dissec- 
tion, reference  and  record  are  at  hand  and  in  order  before  getting 
the  subject  or  beginning  to  work. 

5.  Refer  constantly  to  a  skeleton,  or  to  the  bones  especially  con- 
cerned, or  to  accurate  figures. 

6.  Have  plenty  of  light  upon  the  part  under  dissection,  so  that 
details  of  structure  may  be  seen. 

7.  When  a  part  from  which  or  toward  which  an  incision  is  to  be 
carried  lies  upon  the  meson,  the  incision  should  extend  1-2  cm. 
beyond  the  meson.  This  permits  the  flap  of  skin  to  be  reflected 
across  the  meson  to  that  extent.  If,  however,  this  flap  of  skin  is  to 
be  removed,  tlie  incision  removing  it  should  run  j)arallel  with  the 
meson,  and  upon  the  side  under  examination. 

Objections  to  Mesal  Incisions. — Botli  the  ectal  and  ental  aspects  of  tlie  skin  present  spe- 
cial features  at  some  mesal  points,  and  several  muscles  besides  those  of  the  skin  itself  arise 
at  the  meson,  and  are  liable  to  injury  by  a  mesal  incision.  There  are  two  sides,  presuma- 
bly similar,  but  there  is  only  one  meson. 

8.  Incisions  should  be  as  long  as  may  be  consistently  with  the 
shape  and  structure  of  the  parts,  and  the  dissector's  knowledge  of 
them. 

9.  When  important  or  delicate  parts  are  liable  to  be  injured,  the 
cuts  should  be  shorter  and  more  carefully  made. 

10.  Vessels  and  nerves  should  be  dissected  from  the  center 
toward  the  periphery,  so  as  to  avoid  the  risk  of  missing,  cutting  or 
tearing  the  branches. 

11.  Vessels  injected  with  plaster  should  be  divided  with  the 
arthrotome  or  the  bone  scissors. 

12.  In  place  of  the  block,  especially  while  the  separated  arm  is 
under  dissection,  a  folded  wet  towel  may  be  used ;  this  permits  a 
kind  of  bed  to  be  made  which  keeps  the  arm  in  place. 

13.  "To  put  any  group  of  muscles  on  the  stretch,  put  the  parts 
concerned  in  the  position  into  which  they  would  be  brought  by 
their  antagonistic  muscles.  For  example,  to  put  the  flexors  of  the 
manus  on  the  stretch,  put  the  manus  in  a  state  of  extension,  and 
mce  versaP—Yie2ii\i  (Keen),  A,  16. 

14.  Study  the  actions  of  a  muscle  by  pulling  it  in  the  line  it  nat- 
urally occupies.  Note  the  difference  between  a  direct  and  an  indi- 
rect action.    (Wilder,  4.) 


SUGGESTIONS    FOR    DISSECTORS.  303 

15.  As  a  rule,  muscles  must  be  divided  and  reflected  before  the 
attachments  can  be  fully  determined.  The  attachments  are  usually 
more  distinct  upon  the  ental  aspect. 

16.  "  When  several  similar  muscles  of  a  group — as  those  upon 
the  antebrachium — are  to  be  transected,  cut  them  at  different  levels^ 
so  as  the  more  easily  to  match  their  proximal  and  distal  parts." — 
Heath  (Keen),  A,  16. 

17.  The  borders  of  a  thin  muscle  should  be  grasped  and  slightly 
raised,  first  with  the  forceps  and  then  with  the  fingers.  If  the  other 
border  is  accessible,  it  should  be  treated  in  the  same  way,  and  then 
the  entire  width  at  about  the  middle  raised  to  permit  the  passage 
of  a  scalpel. 

18.  In  transecting  a  wide  muscle,  cut  one  border,  then  lift  it, 
keeping  the  sides  of  the  cut  separate,  and  cut  a  little  deeper, 
applying  the  scalpel  to  the  edge  of  the  muscle. 

19.  Avoid  cutting  muscles  at  their  attachments.  If  it  is  desirable 
to  remove  part  of  a  large  muscle,  leave  a  small  piece  of  the  body 
attached  to  each  tendon.  If  necessary — for  special  reasons — to  re- 
move an  entire  muscle,  insert  the  edge  of  the  arthrotome  in  the  angle 
formed  by  the  attached  ends  and  the  bones. 

20.  Parts  under  dissection  should  be  wet  occasionally  with  a 
mixture  of  water,  glycerin  and  clove-oil  (§  170). 

21.  Parts  which  have  been  exposed,  but  are  no  longer  under 
actual  dissection,  should  be  covered  with  skin  or  rubber-sheeting, 
or  with  a  bit  of  cloth  wet  with  the  glycerin  mixture ;  and  a  dry 
towel  should  be  laid  over  all. 

22.  ''  Put  all  fragments  on  a  piece  of  paper." — Hodges,  A. 

§  597.  Avoid  especially  the  following :  drying^  tailing^  peclcing, 

Tlie  prevention  of  drying  has  been  already  considered. 

Tailing  is  the  making  of  a  shalloio  cut  at  the  beginning  or  the 
end  of  an  incision.  It  is  especially  apt  to  occur  with  beginners, 
and  while  dividing  the  skin.  To  avoid  it,  hold  the  point  of  the  scal- 
pel perpendicularly  to  the  surface  at  both  the  beginning  and  the 
end  of  the  incision. 

Peclcing. — We  use  this  homely  word  to  designate  one  of  the 
most  common  and  most  pernicious  faults  of  anatomical  beginners, 
the  habit  of  aimlessly  poJcing  and  pinching  the  parts^  espe- 
cially while  showing  them  to  the  teacher  or  demonstrator.  It 
reminds  the  observer  of  nothing  so  much  as  the  dabbing  and  peck- 
ing which  hens  inflict  upon  a  piece  of  meat.     The  student  should 


204  ANATOMICAL    TECHNOLOGY. 

bear  in  mind  that  a  single  false  cut,  and  even  a  pincli  in  the  wrong 
place,  may  mar  his  work  beyond  repair ;  he  should  exercise  con- 
stant self-control,  and  never  touch  the  specimen  excepting  for  a 
definite  and  sufficient  reason. 

Pecking  is  only  one  of  several  forms  of  what  may  be  called 
anatomical  Philistinism;  a  lack  of  appreciation  of  delicacy, 
whether  in  structure  or  in  methods  of  manipulation. 

§  598.  Clipping  the  Hair.— Unless  the  skin  is  to  be  preserved, 
or  there  is  some  other  objection,  the  hair  should  he  removed  from 
a  specimen  which  is  to  be  preserved  in  alcohol  and  dissected  at 
intervals. 

If  the  hair  is  allowed  to  remain,  it  interferes  with  the  accuracy  of  dermal  incisions,  and 
with  the  ease  of  making  them  ;  it  is  apt  to  become  detached  and  disfigure  the  dissections  : 
finally,  unless  considerable  time  is  spent  in  squeezing  out  the  alcohol  when  the  specimen 
is  removed  from  the  jar  and  the  water  when  it  is  returned  thereto,  the  hair  causes  both  a 
waste  and  a  weakening  of  the  alcohol  in  which  the  specimen  is  preserved. 

Use  the  hair  scissors  (§  158)  or  a  pair  of  ordinary  scissors  with 
the  points  blunted.  The  hair  is  more  easily  cut  against  its  inclina- 
tion, that  is,  with  the  scissor  points  directed  cephalad  upon  the 
soma  and  proximad  upon  the  limbs.  After  abdominal  transection, 
begin  at  the  cut  border  of  the  skin. 

Clipping  is  facilitated  by  wetting  the  tips  of  the  hair  with  a 
sponge  only  moderately  full  of  water  or  weak  alcohol.  Cut  close 
to  the  skin.  The  operation  usually  occupies  about  an  hour.  Do 
not  put  the  removed  hair  into  the  sink.  Place  it  in  the  waste-pail, 
to  be  buried. 

§  599.  Cutting  the  Skin. — If  the  hair  remains,  wet  it  with  15 
per  cent,  glycerin,  or  dilute  alcohol,  or  water,  along  the  line  of  the 
proposed  incision.  Then,  with  a  small  comb,  or  the  tracer,  or  the 
handle  of  a  scalpel,  part  the  hair  evenly  along  the  same  line  so  as 
to  expose  the  skin  clearly  (§  354).  If  the  hair  has  been  removed, 
indicate  the  line  of  incision  by  a  scratch  made  with  the  tracer  or  the 
point  of  the  scalpel. 

Place  the  tips  of  the  left  index  and  medius,  one  upon  each  side 
of  this  line,  at  the  cut  border  of  the  skin,  and  divaricate  them  so  as 
to  stretch  the  intervening  skin. 

Grasp  the  scalpel  like  a  pen,  at  an  angle  of  45°,  and  divide  the 
skin  by  a  single  steady  stroke  as  far  as  the  tension  exists. 

At  the  beginning  and  end  of  the  stroke,  make  the  scalpel  nearly 
perpendicular  so  as  to  avoid  tailing  (§  597). 


REMOVING     THE    SKIN.  205 

Unless  one  is  quite  familiar  with  both  the  locality  and  the  art  of 
dissecting,  this  first  incision  should  merely  divide  the  skin  proper. 
The  borders  may  be  still  farther  divaricated,  and  a  similar  incision 
made  through  the  connective  tissue  and  fat,  and  in  some  cases  the 
dermal  muscle  (§  629),  until  the  darker  red  and  closer  texture 
shows  that  the  ordinary  skeletal  muscles  have  been  reached. 

With  lean  animals  this  second  incision  will  be  very  shallow,  but 
in  some  cases  the  fat  forms  thick  layers  between  the  dermal  mus- 
cles and  the  skin  and  deeper  muscles.  On  the  cheeks  of  old  males, 
and  sometimes  on  other  regions,  the  skin  and  connective  tissue  are 
so  thick  as  to  puzzle  the  beginner. 

Shift  the  tips  of  the  index  and  medius,  and  repeat  the  operation 
to  the  end  of  the  line.  The  separate  strokes  should  join  each  other 
accurately,  so  that  the  entire  incision  is  straight  and  smooth-edged. 

After  the  skin  is  divided,  the  subcutaneous  fat  and  connective 
tissue  may  usually  be  cut  to  the  proper  depth  by  a  single  long 
steady  stroke. 

§  600.  Removing  the  Skin. — The  edge  of  the  area  of  skin  to  be 
removed,  preferably  at  the  angle  formed  by  two  incisions,  should  be 
grasped,  first  by  the  forceps  and  then  by  the  fingers,  and  lifted  so 
that  the  scalpel  may  be  applied  to  the  connective  tissue  by  which  it 
and  the  fat  are  held  loosely  to  the  deeper  muscles. 

Excepting  in  the  case  of  some  rare  form  (which  should  not  be 
dissected  by  a  beginner),  the  skin  should  be  kept  well  upon  the 
stretch,  and  the  edge  of  the  scalpel  should  be  applied  against  the 
tissues  to  be  exposed,  following  the  direction  of  the  muscular  fibers. 
The  object  is  to  remove  with  the  skin  all  the  subcutaneous  fat,  con- 
nective tissue  and  ectal  fascia,  so  as  to  expose  at  once  and  fully  the 
surface  of  the  muscles,  etc.,  to  be  examined. 

This,  the  anatomical  method  of  removing  the  skin,  is  more  difii- 
cult  than  the  ''flaying"  of  the  butcher  or  the  ''skinning"  of  the 
taxidermist.  Both  of  these  desire  the  skin  free  of  fat  and  connective 
tissue,  and  therefore  keep  the  edge  of  the  knife  turned  toward  it. 
The  taxidermist  must  avoid  stretching,  but  this  is  easier  than  to 
follow  strictly  the  above  method.  The  beginner  will  usually  be 
tempted  to  get  the  skin  off  in  the  easiest  and  quickest  way,  which 
is  that  of  the  butcher ;  but  he  then  is  obliged  practically  to  repeat 
the  operation  for  the  removal  of  the  tissues  which  should  have 
been  lifted  with  the  skin. 

§  601.   Rigor  Mortis. — The  spontaneous  stifiening  of  the  mus' 


206  ANATOMICAL     TECHNOLOGY. 

cles  which  supervenes  soon  after  death  renders  dissection  difficult. 
The  condition  usually  passes  off  within  a  few  hours,  and  may  be 
speedily  overcome  by  immersing  the  animal  for  40-60  minutes  in 
water  at  about  35°  C.  (95°  F.). 

DESCEIPTIONS   OF   CERTAIN    MUSCLES. 

§  603.  Limitation.— For  the  reasons  stated  in  §  128,  the  myological  portion  of  this 
work  directly  relates  to  only  about  one  fifth  of  the  whole  number  of  muscles  which  have 
been  enumerated  in  the  cat.  As  with  the  bones,  however,  (§  368),  the  student  is  advised 
to  pursue  the  subject  further,  making  original  drawings  and  descriptions  of  at  least  one 
muscle  in  another  part  of  the  body.  Whether  it  can  be  at  once  identified  with  some  mus- 
cle in  man  is  ot  less  importance,  so  far  as  the  training  of  the  pupil  is  concerned,  than  the 
accurate  determination  of  its  connections  and  other  characters. 

§  603.  The  Method  here  Followed. — With  few  exceptions,  each  of  the  forty  muscles 
here  considered  is  described  under  the  following  heads : — 

1.  Synonymy. — We  have  given  the  names  for  the  same  muscle  employed  by  Straus- 
Durckheim  and  Mivart,  and  the  names  for  what  appears  to  us  to  be  the  homologous  mus- 
cle in  man  and  in  the  horse.  The  anthropotomical  names  are  taken  from  "  Gray  "  and 
**  Quain,"  and  the  hippotomical  ones  from  the  French  and  the  English  (Fleming's)  editions 
of  "  Chauveau."  In  some  cases,  we  have  been  unable  to  satisfy  ourselves  as  to  the  homol- 
ogy- We  should  have  been  glad  to  include  references  to  the  works  of  Leyli  (A)  and 
Gurlt  (A)  upon  the  horse,  to  Krause's  Anatomy  of  the  rabbit  (A),  and  to  Coues's  paper  on 
the  opossum  (47).     The  authors'  names  are  indicated  by  the  initial  letters  only. 

2.  Figures. — Here  are  enumerated  the  figures  wherein  the  muscle  appears. 

3.  General  Descriptian. — This  is  a  brief  indication  of  the  general  form  and  connections. 

4.  Posture. — We  have  indicated  the  position  of  the  body  or  limb  which  seems  most 
favorable  to  the  examination  of  the  muscle. 

5.  Exposure, — Here  are  given  directions  for  bringing  the  muscle  into  view  by  the 
removal  ot  the  skin  or  overlying  parts. 

6.  Dissection. — This  includes  the  operations  by  which  the  borders  of  the  muscle  are  to 
be  raised,  its  body  transected  and  the  ends  reflected  so  as  to  display  the  attachments. 

7  and  8.  Origin  and  insertion. — Here  are  given  more  detailed  descriptions  of  the  two 
attachments. 

In  addition  to  the  above,  a  complete  account  of  each  muscle  should  embrace  its  nervous 
and  vascular  supply,  its  actions,  direct,  indirect  and  associated,  and  its  variations. 

Errors  and  Defects. — During  the  past  four  years  the  descriptions  and  directions  here 
given  have  been  employed  by  the  students  in  the  anatomical  laboratory  of  Cornell  Univer- 
sity. Inasmuch,  however,  as  annual  modifications  have  been  found  necessary,  we  cannot 
hope  that  their  present  form  is  altogether  what  it  should  be,  and  we  shall  be  very  grate- 
ful for  the  correction  of  errors  and  the  pointing  out  of  defects.     . 

We  desire  here  to  repeat  the  expression  of  our  sense  of  obligation  to  Prof.  T.  B. 
Stowell,  who  has  kindly  followed  the  descriptions  and  directions  scalpel  in  hand,  and  has 
given  us  the  benefit  of  many  valuable  suggestions  and  criticisms  as  to  both  the  facts  and 
the  method  of  stating  them,  and  as  to  the  extent  of  variation  in  different  individuals. 

A  former  special  student.  Dr.  E.  M.  Howard,  generously  placed  at  our  disposal  for 
comparison  his  manuscript  descriptions  of  the  muscles  of  the  cat. 

§  604.  The  Names  of  the  Muscles. — The  number,  extent  and  nature  of  the  changes 
proposed  in  the  names  of  the  muscles  are  set  forth  in  the  Table  on  p.  207. 

In  that  Table  the  names  in  the  left  hand  column  are  those  adopted  in  the  present  work  ; 


TABLE    OF    THE    MUSCLES. 


207 


those  in  the  right  hand  column  are  Latinized  from  those  employed  by  Straus-Durckheim ; 
those  in  the  middle  column  occur  in  standard  works  upon  Human  Anatomy,  or  in  the 
writings  of  anthropotomists.  In  the  last  column  are  words  or  abbreviations  indicating 
the  changes  which  have  been  made  in  the  names  employed  by  Straus-Durckheim  (S.-D.) 
or  anthropotomists  (anth.) :  thus,  abbrev.  =  abbreviated  ;  tr'l'd  =  translated ;  uuif.  = 
unified. 

§  605.   TABLE. 


Here  Adopted. 

Fig. 

Anthropotomy. 

Straus-Durckheim. 

Changes. 

Spino-trapezius 

Acromio-trapezius  . . 

Clavo  trai)ezius 

Occipito-scapularis.. . 
Rhomboideus 

Sterno-mastoideus . . 

Clavo-mastoideus . . . 

Levator  claviculse. . . 
Dermo-liumeralis . . . 
Latissimus     

63 
66 
67 
67 

67 

67 

67 
60 
67 

06 

72 
72 

72 

72 
78 

73 

75 
73 
67 
67 

07 
67 

74 
75 
75 
74 
74 

75 

74 
74 
74 

75 

75 

74 
74 

74 

Trapezius  (in  part).. 
«              It 

Rhomboideus  capitis 
Rhomboideus  major. 
j  Sterno  mastoide- ) 
(      us  (in  part) .  .  .) 
S  Stei-no-mastoide- 
1      us  (in  part) ..." 
Levator  claviculae. . . 

Latissimus  dorsi 

Deltoideus  (in  part). 

Dorso-cucullaris  . . . . 
Acromio-cucullaris. . 
Clavo-cucullaris.  . . . 
Occipito-scapularis. . 
Rhomboideus 

Sterno-mastoideus. . 

Cleido  mastoideus . . 

Transv.-scapularis.. 
Darmo-humeralis. . . 

Latissimus  dorsi 

Delto  clavicularis. .  . 
Pecto-antebrachialis 

Large  pectoral 

(Grand    pect.    (in) 
•<  part)  and  sterno  V 
(  trocliiterianus..  ) 
Grand  pect.  (in  part). 
Serr.  mag.  (in  part) . 
II             i( 

Coraco-bracliialis . . . 

Subscapularis 

Supraspinatus 

Delto  spinalis 

Delto-acromialis 

Infraspinatus 

Micostalis. .        ... 

S.-D.,unif.&tr'rd. 

S.-D.,  translated. 

S.-D.,  translated. 

S.-D. 

S.-D.-  anth.,  abbrev. 

S.  D.  &  anth. 

S.  D.,  translated. 

Anth. 

S.-D. 

S  D  •  anth  ,  abbrev 

Clavo-deltoideus 

Pecto-antebrachialis. 

S.-D.,  transposed. 
S.  D. 

Ectopectoralis 

Entopectoralis 

Xiphi-humeralis 

Serratus  magnus  . . . 
Levator       anguli   ) 

scapulas c  ) 

Coracoideus 

Subscapularis 

Supraspinatus 

Spino-deltoideus.    . . 
Acromio-deltoideus. . 

Infraspinatus 

Micostalis 

Pectoralis  major.. . . 
Pectoralis  minor. . . . 

Generalized. 
Generalized. 
New. 

Serratus  magnus. . . 

Lev.  ang.  scap 

Coracoideus 

Subscapularis 

Supraspinatus 

Deltoideus  (in  part). 

ei                       « 

Infraspinatus 

Teres  minor 

Teres  major 

Dorso-epitrochlearis 
Triceps  (in  part) 

S  Triceps    (in    part) 
]      and  anconeus. . . 
Supinator  longus. . . 

Biceps 

Bracliialis  anticus. . . 
j  Ex.     carpi     rad.  / 

}     longior ) 

\  Ex.     carpi     rad. ) 

)      brevior f 

Ex.  digitorumcom. . 
Ex.  minimi  digiti   . . 

Ex.  carpi  ulnaris 

Extensor  indicis.  . .  . 

Pr.  radii  teres 

Fix.  carpi  radialis  . . 

Anth.  and  S.-D. 

Anth. 

Anth..  abbrev.;  S.-D. 
Anth.  &  S.-D. 
Anth.  &  S.-D, 
S.-D.,  transposed. 
S.-D.,  transposed. 
Anth.  &  S.-D. 
S.-D. 

Teres 

Teres 

S.-D.;  anth.,  abbrev. 

Epitrochlearis 

Meditriceps 

Ectotriceps 

Triceps  (in  part) 

Triceps  medius 

Triceps  externus 

j  Tri.  int.  (in  part) } 
1      and  anconeus. ) 
Supinator  longus. . . 
Biceps      

Anth.,  abbrev. 
S.-D.,  abbrev. 
Generalized. 

Entotriceps 

Supinator  longus. . . 
Biceps 

S.-D.,  abbrev. 

Anth.  &  S.-D. 
Anth  &  S  -D. 

Bracliialis 

Brachialis 

S.-D.;  anth.,  abbrev. 

Extensor      (carpi)  }^ 
radialis  longior.  \ 

Extensor      (carjn) } 
radialis  brevior.  \ 

Extensor  communis. 

Extensor  minimi  . . . 

Extensor  ulnaris  . . . 

Radialis  primus 

Radialis  secundus. . . 

Ex.  dig.  communis. . 
Ex.  proprius  minimi 
Cnbitalis 

Anth.,  abbrev. 

Anth  ,  abbrev. 

Anth.,  abbrev. 
Anth  ,  abbrev. 
Anth.,  abbrev. 

Indic'itor 

Indicator 

S-D 

Pronator  teres 

Flexor  radialis 

75 
75 

Pronator  teres 

Cercialis 

S.-D.;  anth., abbrev. 
Anth. ,  abbrev. 

208  ANAT03IICAL    TECHNOLOGY. 

Where  more  than  one  name  is  used  in  Human  Anatomy,  the  shortest  is  here  given; 
the  coracoideus,  for  example,  is  often  called  coraco-brachialls,  and  the  sterno-mastoideus, 
sterno-cleido-mastoideus. 

The  occipito-scapularis,  levator  elaciculcB  and  dorso-epitrochlearis  occur  in  man  only  as 
anomalies,  and  have  received  names  in  addition  to  those  here  selected. 

The  names  employed  by  Straus-Durckheim  have  been  put  into  their  classical  and  tech- 
nical form,  excepting  in  the  case  of  the  "  large  pectoral"  and  "grand  pectoral."  It  is 
probable  that  one  cause  of  the  slight  use  made  of  the  names  of  this  eminent  anatomist  is 
the  fact  that  he  chose  to  publish  them  in  the  vernacular  form. 

§  606.  The  Sources  of  the  Names  Here  TJsed.—Oi  the  names  of  the  40  muscles  here 
described,  seven  are  employed  both  by  Straus  Durckheim  and  in  the  standard  works  upon 
Human  Anatomy;  these  are:  sterno-mast'ddeus,  se^^ratasmagnus,  subscapnlaris,  supraspi- 
natus,  infi'ospinatus,  biceps,  and  supinator  long  as. 

The  following  three  names  have  been  applied  in  Human  Anatomy,  but  aic  not  used  by 
Straus-Durckheira  :  levator  claviculce,  levator  anguli  scapnlce,  and  coracoideus. 

The  following  nine  names  are  used  by  Straus-Durckheim,  but  not  by  anthropotomists  : 
occipito-scapularis,  rhomboideus,  micostalis,  teres,  hrachia'is,  indicator,  pronator  teres,  dermo- 
humeralis,  and  pecto-antebrachialis.  The  last  two  refer  to  muscles  which  do  not  exist  in 
man,  and  four  of  the  others  are  but  slight  modifications  of  the  anthropotomical  names. 

The  following  eight  names  are  abbreviations  of  the  anthropotomical  names  ;  latissimvs,  ^ 
epitrochlearis,  extensor  radinlis  longior,  ex.  rad.  brevior,  ex.  communis,  ex.   ulnaris,  ex. 
minimiy  and  flexor  radiaUs. 

The  following  seven  names  are  translations  or  transpositions  of  those  used  by  Straus- 
Durckheim  :  acromio-tnipezius,  clavo-trapezius,  spino-deltoideus,  acromio-deltoideus,  claxo- 
deltoideus,  clavo-mastoideus,  and  meditriceps.  As  to  the  hybrid  nature  of  some  of  these 
terms,  see  §  53. 

The  following  four  names  are  the  names  in  common  use  modified  after  the  analogy  of 
the  now  almost  universally  adopted  ectoglutmus  :  eetopectoralis,  entopectoralis.  ectotriceps, 
entotriceps. 

Two  names  remain  to  be  accounted  for.  One  of  these,  spino -trapezius,  was  substituted 
for  Straus-Durckheim's  dorso-cucullaris  for  the  sake  of  uniformity  with  respect  to  the 
other  divisions  of  the  human  trapezius,  and  the  correlative  division  of  the  deltoideus. 

This  leaves  us  responsible  for  but  one  entirely  new  name,  xiphi-humeralis.  While  the 
muscle  so  designated  seems  to  us  suflSciently  distinct  to  demand  a  separate  appellation,  we 
are  not  particularly  pleased  with  the  name,  and  stand  ready  either  to  accept  a  shorter  one 
or  to  regard  the  muscle  as  only  a  division  of  the  eetopectoralis  or  entopectoralis  when  the 
proper  evidence  is  forthcoming. 

THE  TRAPEZIUS   GROUP. 

§  607.  General  Remark.— The  human  M.  trapezius,  a  single  muscle,  seems  to  be  rep- 
resented  in  the  cat  by  three  nearly  distinct  muscles,  which  are  here  called — beginning 
with  the  most  caudal — spino-trapezius.  acromio-trapezius,  and  clavo-trapezius.  They  extend 
from  the  cervical  and  thoracic  dorsimeson  to  the  scapula  and  clavicl^. 

The  names  of  all  the  muscles  are  in  italics.  To  avoid  frequent  repetitions,  the  capital 
M,  the  initial  of  Musculus,  will  be  prefixed  only  when  otherwise  there  might  be  some  risk 
of  misunderstanding. 

§  608.   Explanation  of  Fig.  66. — The  left  ectal  skeletal  nmscles 
of  the  neck  and  shoulder. 


THE    TRAPEZIUS    GROUP.  209 

Preparation. — A  subtriangular  flap  of  skin  was  lifted  as  di- 
rected in  §  610,  together  with  the  dermal  nmscles  connected  there- 
with. The  flap  was  reflected  dorsad,  but  is  omitted  from  the  figure ; 
the  reflected  dorsal  end  of  the  dermal  muscle  called  supra-cervico- 
cutaneus,  however,  is  shown.  Both  cut  edges  of  the  skin  were 
lifted  and  retracted  or  reflected  slightly. 

The  dermo-Tiumeralis  (§  629)  was  mostly  removed  with  the  skin, 
but  its  brachial  end  appears  just  dorsad  of  the  elbow.  The  fat  and 
connective  tissue  have  been  removed  so  as  to  leave  the  borders  of 
the  muscles  more  distinct.  From  the  hiatus  trapezii^  just  dorsad 
of  the  convexity  of  the  shoulder,  the  fat  has  been  removed  so  as  to 
expose  the  lymphatic  gland  {Gl,  lymphatica)^  and  the  hiatus  itself 
was  extended  dorsad  so  as  to  expose  the  ventral  or  lateral  margin 
of  the  occipito- scapular  is. 

t 

In  tins  and  the  other  descriptions  of  the  myological  figures,  the  parts  are  enumerated 
under  three  heads :  bones,  etc.  ;  muscles  ;  vessels,  nerves,  glands,  etc. 

Bones.— CTaCTCM^^i — Collar  bone  (§  422). — In  this  figure  the  bone  itself  does  not  appear, 
but  the  position  of  its  mesal  or  sternal  end  is  indicated  by  the  dotted  line  from  the  word 
clavicula  ;  see  rhaphe. 

Mesoscapiila — Spine  of  the  scapula  (§  390). — The  positiou  of  this  ridge  of  the  scapula, 
intervening  between  the  MM.  acromio-trnpezius  and  spino-deltoideus,  is  approximately- 
indicated  by  the  name.     It  is  more  distinctly  shown  in  Fig.  67. 

Metacromion  (§  396). — This  process  of  the  glenoid  end  of  the  mesoscapula  may  be  felt 
through  the  muscles  at  a  point  corresponding  with  the  beginning  of  its  name. 

Fascia. — This  strip  of  fascia — hardly  deserving  the  name  of  ligament — passes  from  the 
lateral  or  scapular  end  of  the  clavicle  to  the  surface  of  the  M.  supraspinatus,  as  better 
shown  in  Fig.  67. 

Rhaphe  (trapezio-deltoidea)  (§  616). — This  line  or  seam  of  connective  tissue,  between 
the  M.  davo-deltoideus  and  the  MM.  clavo-trapezius  and  claM-mastoideus  (Fig.  67),  coin- 
cides nearly  with  the  position  of  the  clavicle.  It  is  usually  more  distinct  upon  the  ental 
aspect,  and  is  somewhat  exaggerated  in  the  figure.     The  word  is  sometimes  spelled  rapM. 

SpincE  neurales  vertebr.  (vertebrarum)  thoraci.  (thoracicorum), — The  third  and  thirteenth 
thoracic  ("  dorsal")  neural  spines  (Fig.  30). — The  spines  themselves  do  not  appear,  but  the 
numbers  3  and  13  indicate  the  positions  of  the  third  and  the  last  of  the  series. 

Muscles. — In  the  figure  the  name  of  each  muscle  is  preceded  by  M.,  the  initial  of 
MuschIus. 

Acromio-deltoideus— The  acromial  portion  of  the  deltoid  (§  670). — This  is  the  interme- 
diate one  of  the  three  muscles  which,  in  the  cat,  seem  to  represent  the  single  deltoid 
muscle  of  man.  It  and  the  spino-deltoideus  are  inserted,  like  the  human  deltoid,  ujwn 
the  humerus;  but  the  third  portion,  the  clavo-deltoideus  (the  "  delto-claviculaire "  of 
Straus-Durckheim)  is  associated  with  the  Irachialis  and  insarted  upon  the  ulna. 

Acromiotrapeziiis — The  acromial  portion  of  the  human  trapezius  (§  613). — This  is  the 

intermediate  one  of  the  three  muscles  which,  in  the  cat,  appear  to  us  to  represent  the 

human  trapezius  (§  607).     In  the  figure  the  name  is  written  obliquely  across  the  scapular 

end  of  the  muscle  ;  the  word  tendon,  near  its  vertebral  end,  indicates  the  imperfectly 

14- 


210  ANATOMICAL    TECHNOLOOY, 

defined  tendon  of  origin  (§  614).     Upon  the  muscle  are  also  written  tlie  names  M.  occipito- 
scapularis,  hiatus  trapezii,  and  Gl.  lymphatica. 

Cervico-auricularls  (§  615). — This  muscle  of  tlie  ear  is  shown  at  the  dorsimeson  between 
the  ear  and  the  M.  supra  cervico-cutaneus ;  its  name  is  omitted. 

Clavo-delt&ideus  (§  637). — See  also  acromio-deltoideus. 

Claw-trapezius  (§  615).— See  also  acromio-trapezius. 

Dermo-humeralis  (§  629). — Most  of  this  dermal  muscle  was  removed  with  the  skin  ;  the 
name  is  written  across  the  brachial  end  which  passes  between  the  MM.  triceps  and  latissi- 
mus  to  be  attached  to  the  latter  and  the  bicipital  arch. 

LatisslmMS  (§  635).— This  is  more  commonly  called  latissimus  dor  si.  Its  caudal  por- 
tion is  covered  by  the  skin ;  its  dorso-cephalic  angle  is  overlapped  by  the  spino-trapezius, 
but  exposed  in  Fig.  67. 

Levator  claviculcB  (§  627). — The  scapular  end  is  seen  to  emerge  from  entad  of  the  davo- 
trapezius,  to  partly  overlap  the  acromio-trapezius  and  to  be  inserted  upon  the  imperlectly 
defined  metacromion  rather  than  upon  the  clavicle,  as  might  be  supposed  from  the  name. 

Occipito-scapidaris  (§  617). — This  is  fully  shown  in  Fig.  67.  Here,  its  lateral  border 
appears  at  the  dorsal  end  of  the  hiatus  trapezii  which  has  been  enlarged  so  as  to  show  the 
position  of  the  muscle. 

8pino-deltoideus  (§  674). — See  also  the  acromio-deltoideus. 

Spino-trapezius  (§  611).— See  the  acromio-trapezius. 

Sterno-mastoideus  (§  622). — Part  of  this  shows  darkly  between  the  skin  of  the  neck  and 
the  clavo-trapezius.    It  is  more  fully  shown  in  Fig.  67  and  72. 

Supra-cervico-cutaneus  (§  615). — Most  of  this  cervical  dermal  muscle  was  lifted  with 
the  skin,  and  only  its  reflected  dorsal  end  is  shown. 

Teres  (§  680). — This  appears  in  the  interval  between  the  spino-trapezius,  spino-deltoideus, 
latissimus  and  triceps.  By  inadvertence,  the  name  is  written  with  the  addition  of  the 
qualifying  adjective  major  ;  since  the  muscle  more  often  called  teres  minor  is  here  desig- 
nated as  micostalis,  there  seems  to  be  no  need  of  a  compound  term  for  the  muscle  in  question. 

Triceps.— 'VYie  name  is  written  across  the  two  largest  portions  of  the  muscle  commonly 
known  as  triceps  in  man.  The  M.  is  upon  the  scapular  head,  here  called  meditriceps 
(§  682),  and  most  of  the  rest  of  the  name  is  upon  the  part  here  called  ectotriceps  (§  684) ; 
the  surface  of  the  latter  presents  a  superficial  furrow. 

Other  Parts. — 01.  {glandula  lymphatica). — A  somewhat  large  lymphatic  gland  embed- 
ded in  the  fat  which  occupies  the  hiatus  trapezii. 

Gl.  {glandula)  parotis — The  parotid  salivary  gland  (Fig.  87). — The  caudal  border  of 
this  usually  pale  gland  is  exposed  by  slightly  cephaloducting  the  occipito-presternal  edge 
of  skin. 

Gl.  {glandula)  suhmaxillans — The  submaxillary  salivary  gland  (Fig.  87). — This  appears 
a  little  ventrad  of  the  Gl.  parotis,  and  is  usually  of  a  deeper  color. 

Hiatus  trapezii  (§  613). — This  is  an  elongated  lozenge  shaped  interval  between  the 
cephalic  margin  of  the  M.  acromio-trapezius  and  the  caudal  and  dorso  caudal  margins 
respectively  of  the  MM.  clavo-trapezius  and  levator  claviculw.  In  reality,  the  very  open 
angle  formed  by  the  intersection  of  these  two  borders  is  near  the  middle  of  the  length  of 
the  hiatus,  but  in  the  preparation  the  margins  of  the  MM.  clavo-trapezius  and  acromio- 
trapezius  have  been  artificially  separated  a  little  farther  dorsad. 

V.  (vena)  jugularis— The  jugular  vein  (Fig.  101). — This  is  exposed  between  the  Jlf. 
clavo-trajyezius  and  the  margin  of  the  skin,  where  it  obliquely  crosses  the  M.  sterno-mastoi- 
deus. 

§  609.   Exposure. — It  is  usually  more  convenient  to  expose  the 


THE    TRAPEZIUS    GROUP. 


211 


entire  trapezius  group  by  lifting  a  single  large  flap  of  skin.  This 
flap,  however,  may  be  divided  afterward  so  that  one  or  two  of  the 
muscles  may  be  covered  while  the  other  is  under  examination.  In 
so  doing,  the  skin  is  more  easily  divided  ento-ectad  (from  within 
outward). 


Fig.  66.— The  Ectal  Skeletal  Muscles  op  the  Left 
Shoulder  and  Neck,  after  removal  op  the  Der- 
mal Muscles.  (The  left  side  of  the  head  is  shown  in 
outline  below  in  order  to  facilitate  the  student's  recogni- 
tion of  the  regions  in  this  his  first  systematic  dissection.) 


212  ANATOMICAL    TECHNOLOGY, 

§  610.  Caution, — In  making  all  incisions  through  the  skin  of 
the  cat,  it  is  necessary,  in  addition  to  the  general  directions  in  §  599, 
to  keep  in  mind  the  presence  of  the  M.  dermo-humeralis  (§  629)  and 
other  muscles  constituting  the  panniculus  carnosus^  a  thin  muscu- 
lar layer  between  the  skin  and  the  proper  skeletal  muscles. 

The  dermal  muscle  is  usually  to  be  divided  and  lifted  with  the 
skin.  AVith  fleshy  animals,  the  risk  of  cutting  at  the  same  time 
the  underlying  skeletal  muscles  is  obviated  by  the  intervention  of  a 
layer  of  fat  which  should  also  be  removed  with  the  skin  (§  600). 
With  lean  animals,  the  two  sets  of  muscles  may  usually  be  distin- 
guished from  the  thinness  and  paleness  of  the  dermal  layer,  and 
from  the  fact  that  it  is  moved  when  the  skin  is  pulled  in  any 
direction. 

Connect  (§  584)  the  prcesternum  (Fig.  30  and  49,  §  228),  with  the 
thirteenth  thoracic  neural  spine  (Fig.  30  and  QQ^  §  227),  and  with  a 
point  1  cm.  cephalad  of  the  crista  lambdoidalis  (Fig.  ^Q,  §  226). 

The  occipito-presternal  incision  should  have  a  slight  caudal  con- 
vexity so  as  to  skirt  the  base  of  the  ear.  The  vertebro-presternal 
incision  should  cross  the  brachium  at  about  the  junction  of  its  first 
and  second  fourths  ;  this  incision  may  be  commenced  at  the  middle 
of  its  length,  and  be  carried  thence  in  both  directions.  Lift  the  flap 
at  the  presternal  angle,  and  remove  with  the  skin  the  fat,  connective 
tissue  and  dermal  muscles.    Reflect  it  across  the  dorsimeson. 

M.   SPINO-TRAPEZIUS. 

§  611.  Synonymy.— The  caudal  part  of  the  human  trapezius,  Q.,  A,  1,  187  ;  G.,  A, 
373;  dorso-cvcullaire,  S.  D.,  A,  TI,  334;  portion  dorsale  du  trapeze,  Ch.,  A,  Fig.  90, 
"  1,"  216  ;  dorsal  trapezius,  Ch.  (Fl.),  A,  203  ;  hinder  portion  of  the  trapezius,  Miv.,  B,  137. 

Figures.— Ectal  aspect  (66) ;  insertion  (67,  44);  transection  (99, 100). 

General  Description. — An  elongated  triangle,  from  the  thoracic 
dorsimeson  to  the  mesoscapula  and  the  surface  of  the  MM.  supra- 
spinatus  and  infraspinatus. 

Dissection.— The  ventro-caudal  border  will  appear  as  a  slightly 
raised  line  nearly  parallel  with  the  presterno- vertebral  margin  of 
the  skin.  In  recent  specimens  the  color  of  the  muscle  is  usually  a 
brighter  red  than  that  of  the  subjacent  M.  latissimus. 

Lift  the  border  near  its  middle,  and  trace  it  mesad,  noting  that, 
about  1  cm.  from  the  meson,  the  muscular  fibers  are  replaced  by  a 
thin  tendon  which  is  not  always  easily  separated  from  the  subjacent 
muscle.     Then  trace  the  border  ventro-cephalad,  noting  that  it 


M.    SPINO-TRAPEZIUS.  21S 

thickens  slightly  as  it  crosses  the  vertebral  border  of  the  scapula, 
and  ends  upon  the  fascia  covering  the  M.  infraspinatus. 

Continue  to  lift  the  ventro-caudal  border,  and  dissect  up  the 
middle  part  of  the  muscle  as  far  cephalad  as  possible  ;  then  pull  it 
caudad,  and  at  the  same  time  dorsad  or  ventrad.  This  will  indicate 
the  cephalic  border,  which  is  much  shorter  than  the  otlier,  and 
extends  latero- ventrad  from  a  point  between  the  1st  and  4th  tho- 
racic neural  spines. 

The  dorsal  half  of  the  cephalic  border  is  muscular,  and  separable 
without  much  difficulty  from  the  adjacent  caudal  border  of  the  M. 
acromio-trapezius.  Opposite,  or  slightly  dorsad  of,  the  vertebral 
border  of  the  scapula,  the  border  of  the  M.  splno-trapezius  becomes 
tendinous,  thin  and  indistinct,  so  that  its  true  limits  are  best  ascer- 
tained by  pulling  upon  the  muscular  portion.  It  is  also  overlapped 
to  some  extent  by  the  M.  acromio-trapezius. 

The  cephalic  border  of  the  muscle  may  easily  be  traced,  entad 
of  the  tendon  of  the  M.  acromio-trapezius^  to  a  point  8-10  mm. 
cephalad  of  the  mesoscapula,  and  about  the  same  distance  from  the 
nearest  part  of  the  border  of  the  scapula.  Here  it  terminates  upon 
the  fascia  covering  the  M.  supraspinatus. 

The  muscle  should  now  be  transected  (§  ^SQ\  and  the  ental 
surface  cleared  of  fat,  especially  near  the  attachments. 

§  612.  Origin. — From  the  tips  and  interspinous  ligaments  of  most 
or  all  of  the  thoracic  neural  spines.  The  attachment  of  the  cephalic 
border  may  be  at  any  point  between  the  1st  and  4th  spine,  and  that 
of  the  ventro-caudal  border  at  any  point  between  the  11th  and  13th. 
The  origin  of  the  caudal  2-3  cm.  is  by  a  triangular  tendon,  the  lat- 
eral angle  of  which  is  1  cm.  from  the  meson.  The  rest  of  the  muscle 
arises  by  fleshy  fibers.  Opposite  the  cephalic  3  or  4  spines  there 
are  sometimes  slight  intervals  filled  with  loose  connective  tissue ; 
opposite  the  others,  the  corresponding  intervals,  when  they  exist, 
are  occupied  by  a  firm  fascia  which  practically  renders  the  attach- 
ment continuous  across  the  spines. 

Insertion. — Along  a  curved  s-shaped  line  obliquely  crossing  the 
mesoscapula  (Fig.  44).  The  cephalic  two  thirds  of  the  insertion  is 
by  a  thin  tendon  1-2  cm.  long  and  1-1.5  cm.  wide,  which  is  attached 
to  the  fascia  upon  the  ectal  aspect  of  the  supraspinatus,  and  to  the 
mesoscapular  tuberosity  which  it  crosses  very  obliquely.  Here  it 
joins  the  caudal  and  usually  fleshy  third  of  the  insertion,  which 
extends  upon  the  fascia  covering  the  infraspinatus  at  an  angle  of 


214  ANATOMICAL    TECHNOLOGY, 

about  45  degrees  with  the  mesoscapula.  On  the  ectal  surface  of  the 
spino-irapezius^  along  the  line  of  union  of  the  muscular  and  ten- 
dinous parts,  is  received  the  insertion  of  the  acromio-trapezius 
(Fig.  67). 

M.  ACEOMO-TEAPEZIUS. 

§  613.  Synonymy.— The  intermediate  part  of  tlie  human  trapezius,  G.,  373;  Q.,  I, 
187;  acromio-cucullaire,  S.-D.,  A,  II  333;  portion  cervicale  du  trapeze,  Ch.,  A,  216,  and 
Fig.  90  ;  cervical  trapezius,  Ch.  (FL),  A,  303  ;  anterior  part  of  the  trapezius,  Miv., 
B,  137. 

Figures. — Ectal  aspect  (66) ;  ental  aspect  and  insertion  (67) ;  insertion  area  (44). 

General  Description.— Thin  ;  sub-trapezoidal  ;  from  the  dorsi- 
meson,  in  the  caudal  part  of  the  cervical  region  and  sometimes  also 
the  cephalic  part  of  the  thoracic,  to  the  metacromion,  and  the  adja- 
cent surface  of  the  M.  spino-trapezins. 

Dissection. — The  caudal  border  has  been  indicated  in  describing 
the  spino-trapezius,  which  is  often  slightly  overlapped  by  it.  It 
nearly  coincides  with  a  line  drawn  between  the  vertebral  ends  of  the 
two  mesoscapula?.  Lift  it  at  the  vertebral  border  of  the  scapula, 
and  note  that,  8-10  mm.  from  the  mescm,  it  becomes  a  thin  tendon 
which  may  be  traced  across  the  meson  to  its  platetrope  without 
severing  any  definite  attachments  to  the  subjacent  parts.  Yen  trad 
it  may  be  traced  to  a  point  about  1  cm.  caudad  of  the  mesoscapula, 
and  1.5  to  2  cm.  from  the  nearest  part  of  the  vertebral  border  of  the 
scapula  where  it  terminates  upon  the  ectal  surface  of  the  spino- 
trapezius. 

The  cephalic  border  of  the  muscle  may  be  recognized  as  forming 
the  caudal  margin  of  a  narrow  intermuscular  interval,  the  hiatus 
trapezii,  at  the  side  of  the  neck,  about  midway  between  the  convex- 
ity of  the  shoulder  and  the  meson.  This  interval  is  filled  with  con- 
nective tissue  and  fat,  in  which  are  imbedded  a  lymphatic  gland 
and  an  artery. 

Follow  this  border  to  the  meson,  noting  that,  for  about  1  cm. 
therefrom,  it  is  either  continuous  with  the  caudal  border  of  the  next 
muscle  {clavo-trapezius)  or  slightly  overlapped  by  it.  They  may 
be  separated,  however,  without  cutting  fibers.  Ventrad  of  the  hia- 
tus this  border  is  usually  overlapped  for  3-5  mm.  by  the  levator 
claviculce,  the  border  of  which  must  be  lifted  with  care.  Transect 
the  acromio-trapezius  at  the  vertebral  border  of  the  scapula. 

§  614.  Origin. — In  two  or  three  parts  :  In  the  caudal  five  eighths 
the  thin  tendon  is  continuous  across  the  meson  with  its  platetrope, 


M.    ACR03II0-TRAPEZIUS.  215 

and  is  connected  with  the  subjacent  parts  only  by  small  nerves  and 
vessels.  It  thus  spans  the  interval  between  the  vertebral  borders  of 
the  scapulae,  which  project  slightly  dorsad  of  the  Intervening  verte- 
bral region.  In  the  next  two  or  three  eighths  the  median  raphe  of 
the  tendon  is  joined  by  a  low  median  fascia  which  springs  from  the 
supraspinous  ligaments.  Sometimes,  in  the  cephalic  eighth,  the 
muscular  fibers  reach  the  meson.  The  line  of  origin  extends  from 
the  caudal  end  of  the  axial  spine  to  some  point  between  the  1st  and 
4th  thoracic  spines,  thus  filling  the  interval  between  the  spino- 
trapezius  and  clavo-irapezius. 

Insertion. — In  three  parts  :  (A)  the  cephalic  fifth  is  attached  to 
the  ectal  surface  of  the  metacromion  (Fig.  44),  and  is  usually  over- 
lapped by  the  dorsal  border  of  the  levator  clamculcB ;  (B)  the  cau- 
dal fourth  or  fifth  is  attached  to  the  ectal  surface  of  the  splno- 
irapezius^  along  a  dorso-caudal  line  forming  an  angle  of  30-45 
degrees  with  the  mesoscapula  ;  (C)  the  intervening  portion  of  the 
muscle  is  inserted  upon  the  glenoid  border  of  the  mesoscapula. 

Remark. — The  most  notable  feature  of  this  muscle  is  the  wide 
tendon  of  origin,  which  with  its  platetrope  forms  a  heart-shaped 
area  with  its  apex  directed  cephalad.  The  office  of  the  muscle 
seems  to  be  mainly  that  of  a  ligament,  to  prevent  the  separation  of 
the  vertebral  borders  of  the  scapulae. 

M.   CLAVO-TRAPEZIUS. 

§  615.  Synonymy. — The  cephalic  or  clavicular  portion  of  the  human  trapezius,  G.,  A, 
373;  Q.,  A,  1, 187 ;  clavo-cucullaire,  S.-D.,  A,  II,  333  ;  part  of  the  ''portion  anterieure  du 
mastoido-humeral,"  Ch.,  A,  209  ;  part  of  the  anterior  or  superior  portion  of  the  mastoido- 
humeralis,  Ch.  (Fl.),  A,  197;  cephalic  part  of  the  '' cephalo-humeral"  Miv.,  B,  147,  and 
Wood,  9,  101,  Fig.  23,  "c."  It  is  thought  by  some  that  this  muscle  does  not  represent 
any  part  of  the  human  trapezius. 

Figures.— Ectal  aspect  (66) ;  ental  aspect  of  reflected  ends  (67) ;  clavicular  end  (72). 

General  Description. — A  wide  tseniate  muscle,  from  the  occiput 
and  the  cephalic  part  of  the  dorsimesori  to  the  clavicle  and  the 
trapezlo-deltoid  raphe. 

Dissection. — The  larger  part  of  the  cephalic  border  of  the  hiatus 
mentioned  under  the  dissection  of  the  acromio-trapezius  is  formed 
by  the  caudal  border  of  the  clavo-trapezius.  Trace  this  border 
dorsad,  bearing  in  mind  its  close  union  with  the  cephalic  border  of 
the  acromio-trapezius.  Tlien  trace  it  ventrad,  using  great  care  in 
lifting  it  from  the  subjacent  levator  claviculce^  and  noting  that,  ven- 


216  ANATOMICAL    TECHNOhOGT, 

trad  of  the  point  of  crossing,  the  interval  between  the  two  muscles  is 
filled  with  a  fascia  so  dense  as  to  practically  unite  them. 

Lift  the  skin  from  1-2  cm.  along  the  occipito-presternal  line. 
Dissect  up  the  caudal  border  of  the  claoo-trapezius  for  2-3  cm.  at 
the  junction  of  its  dorsal  and  middle  thirds,  and  pull  it  caudad. 
This  may  serve  to  indicate  the  position  of  the  ventro-cephalic  bor- 
der near  the  cut  edge  of  the  skin.  Moreover,  between  the  border 
of  the  clavo-irapezius  and  the  caudal  border  of  the  adjacent  sterno- 
mastoideus^  just  caudad  of  the  ear,  will  be  seen  emerging  one  or 
two  nerves. 

Follow  the  border  of  the  clavo-trapezius  to  the  crista  lambdoi- 
dalis,  noting  that,  for  15-20  mm.  therefrom,  it  is  closely  united  with 
the  caudal  border  of  the  adjacent  sterno-mastoideus.  The  two 
muscles  may  usually  be  separated  without  cutting  fibers,  but  some- 
times a  slender  fasciculus  passes  from  one  to  the  other  obliquely  at 
about  the  middle  of  their  length. 

Part  of  the  occipital  end  of  the  muscle  is  covered  by  a  small  tri- 
angular muscle  belonging  to  the  ear.  This,  the  M,  cervico-auricu- 
laris  (subcervico-pavilien  of  Straus- Durckheim,  A,  I,  194),  is  shown 
in  Fig.  QQ^  but  not  named  ;  it  must  be  removed  with  great  care  to  a 
point  just  cephalad  of  the  crista  lambdoidalis.  Trace  the  ventro- 
cephalic  border  of  the  clavo-trapezius  to  the  clavicle,  which  may  be 
felt  in  the  muscles  between  the  prsesternum  and  the  convexity  of 
the  shoulder. 

Transect  the  muscle  at  its  middle ;  in  reflecting  the  ventral  end 
of  the  muscle,  use  great  care  in  separating  it  from  the  subjacent 
clavo-mastoideus,  which  is  also  attached  to  the  clavicle.  After 
reflecting  the  dorsal  part,  divide  it  lengthwise  along  a  line  corre- 
sponding with  the  angle  formed  by  the  meson  with  the  crista  lambdoi- 
dalis ;  the  wider  of  the  strips  so  formed  may  then  be  reflected  across 
the  meson,  and  the  narrower  upon  the  head,  as  shown  in  Fig.  67. 

§  616.    Origin.— In  two  parts :  (A)  by  a  thin  tendon  5-10  mm. 

long,  from  the  mesal  10-15  mm.  of  the  crista  lambdoidalis ;  (B)  by 

A  fleshy  fibers  from  the  supraspinous  ligament  for  4-5  cm.  from  the 

,  crest  to  the  caudal  end  of  the  axial  neural  spine  (Fig.  30,  §§  208,  471). 

Insertion. — The  details  of  the  insertion  differ  considerably  in 
individuals,  and  perhaps  in  the  same  individual  according  to  age 
and  the  development  of  the  clavicle.  Sometimes  the  sternal  end  of 
the  clavicle  projects  about  1  mm.  mesad  of  the  M,  clavo-trapezius^ 


M,     OCCIPITO-SCAPULABIS,  21? 

wMle  in  other  cases  the  muscle  extends  mesad  of  the  bone  so  as  to 
join  the  border  of  the  ectopectoralis. 

Pull  the  muscle  dorso-cephalad,  and  note  its  apparent  continua- 
tion across  the  clavicle  with  the  clavO'deltoideus.  The  muscles, 
however,  are  joined  by  a  raphe,  the  trapezio-deltoid,  which  is  more 
apparent  upon  the  ental  aspect.  Most  of  the  clavo-trapezius  is 
inserted  upon  this  raphe  ;  but  the  ental  fibers  of  the  cephalo- ventral 
third  or  fourth  are  attached  directly  to  the  ventral  border  of  the 
sternal  and  straighter  half  of  the  clavicle.  Variations  in  the  mode 
of  insertion  should  be  noted,  drawn  and  reported. 

M.  OCCIPITO-SCAPULAHIS. 

§  617.  Synonymy. — There  seems  to  be  some  doubt  as  to  its  human  homologue  ;  rTwrru 
hoideas  capitis,  Miv.,  B,  145,  and  Wood,  9,  92,  Fig  23,  "  d"  ;  occipito-scapulaire,  S.-D.,  A, 
II,  331 ;  part  of  rhomho'ide,  Ch.,  A,  202  ;  part  of  rhomhoideus,  Ch.  (Fl.),  A,  188. 

Figures. — Slightly  at  the  dorsal  end  of  the  hiatus  trapezii  (66) ;  ectal  aspect  (67) ; 
lateral  border  (73) ;  insertion  area  (45). 

Exposure. — by  the  removal  of  the  3fM,  acromio-  and  clavo- 
trapezius. 

General  Description. — Narrow,  tseniate,  near — and  nearly  par- 
allel with — the  dorsimeson,  from  the  crista  lambdoidalis  to  the 
coraco-vertebral  angle  of  the  scapula. 

Dissection. — About  midway  between  the  occiput  and  the  scapula 
the  lateral  border  of  the  muscle  appears  as  a  slightly  raised  line 
10-15  mm.  from  the  meson.  Trace  it  nearly  to  the  occiput.  Lateri- 
duct  the  middle  of  the  cephalic  half  of  the  muscle  so  as  to  indicate 
its  mesal  border  ;  then  transect. 

§  618.  Origin. — By  fleshy  fibers  from  the  crista  lambdoidalis, 
entad  of  the  origin  of  the  clavo-trapezius^  beginning  5-10  mm.  from 
the  meson,  and  extending  12-15  mm.  laterad  to  a  point  nearly  in 
line  with  the  temporo-parietal  suture  (§  493),  where  it  is  overlapped 
by  the  dorsal  border  of  the  sterno-mastoideus.  Caudad,  the  mus- 
cle gradually  approaches  the  lateral  border  of  the  rhomhoideus. 
At  the  junction  of  the  third  with  the  last  fourth,  the  muscle  narrows 
and  thickens,  so  as  to  become  prismatic  rather  than  tseniate. 

Insertion. — The  narrowing  muscle  is  wedged  pretty  closely 
between  the  rhomhoideus  at  its  mesal  side  and  the  levator  anguli 
scapulcB  at  its  lateral  side,  and  is  inserted  either  between  these  mus- 
cles upon  the  coraco- vertebral  angle  of  the  scapula  (Fig.  45),  6-16 
mm.  cephalad  of  the  mesoscapula,  or  upon  the  ental  surface  of  the 


21S 


ANATOMICAL     TECHNOLOGY. 


second  muscle  close  to  its  own  insertion  ;  in  some  cases,  these  two 
forms  of  attachment  coexist. 

§  619.  Explanation  of  Fig.  67. — The  second  layer  of  skeletal 
muscles  of  the  left  shoulder  and  neck. 

Preparation. — After  the  reflection  of  the  skin  and  derma!  mus- 
cles as  in  Fig.  QQ,  the  following  muscles  were  transected  and  re- 
flected:  spino-trapeziuSy   acromio-trapeziuSy  clavo-trapezius  and 


Fig.  67. — The  Secoot)  Layer  of  Skeletal  Muscles  op  the  Neck  and  Shoulder. 

levator  clamculce.  The  skin  was  also  removed  from  the  left  side  of 
the  head,  together  with  the  external  ear,  the  parotid  and  submaxil- 
lary salivary  glands,  and  parts  of  the  MM.  temporalis  and  masseter. 


Bones. — Acromion  (§  392). — This  process  of  the  mesoscapula  is  seen  to  afford  origin  to 
the  acromio-deltoideus. 

Clamcula  (§§  423,  608). — By  the  reflection  of  the  davo-trapezius  and  the  deflection  of 
the  clavo-mastoideus,  the  clavicle  is  brought  into  view.  Its  name  is  connected  with  its 
eternal  end. 


31.     RHOMBOIDEUS.  219 

Crista  lamldoidalis — The  lambdoid  ridge  of  the  skull  (Fig.  56). — The  crest  itself  does 
not  distinctly  appear,  but  its  position  coincides  with  the  lines  of  attachment  of  the  occvpito- 
scapularis  and  sterno-mastoideus  and  part  of  the  clavo-trapezius. 

Mesoscapula  and  metacromion  (Fig.  44  and  §  608). 

Trochiter — The  larger  or  cephalic  tuberosity  of  the  humerus  (Fig.  30  and  74,  §  420). 

Zygoma — The  zygomatic  arch  (Fig.  30,  56,  §§  207,  229). — The  outlines  of  this  promi- 
nent bony  arch  are  shown  just  dorsad  of  the  name. 

Muscles. — The  acromio-deltokleus  (§  670),  dermohumeralis  (§  629),  spino-deltoideus 
(§  674),  teres  {%  680),  and  triceps  {%%  682,  684),  are  sufficiently  described  in  the  explanation 
of  Fig.  66  (§  608),  and  the  supraspinatiis,  infraspinatus  and  teres  (the  word  major  is  super- 
fluous) in  the  explanation  of  Fig.  74  (§  672).  The  masseter,  temporalis,  splenius  and 
digastricus  are  not  particularly  described  in  this  work. 

Acromio-trapezvjs  (Fig.  66,  §  613). — This  was  transected  so  as  to  leave  the  semicordate 
tendon  wholly  in  the  vertebral  part,  which  is  reflected  dorsad.  The  scapular  part  is 
slightly  lifted  so  as  to  show  the  manner  of  its  connection  with  the  ectal  surface  of  the 
spino-trapezius. 

Clavo-trapezius  (Fig.  66,  §  615). — The  clavicular  end  has  been  reflected.  The  other  and 
much  wider  end  was  longitudinally  divided  from  the  angle  between  the  cephalic  and  mesal 
parts  of  the  origin,  and  the  two  portions  thus  formed  were  reflected  respectively  cephalad 
and  dorsad.     The  name  is  written  upon  the  latter  only. 

Latissimiis  (Fig.  66,  §  635).— By  the  removal  of  the  vertebral  end  of  the  spino-trapezius, 
the  dorso-cephalic  angle  of  this  muscle  is  exposed.  In  the  interval  between  its  cephalic 
border  and  the  caudal  border  of  the  rhomboideus,  are  seen  some  of  the  proper  vertebral 
muscles.  By  inadvertence,  the  fibers  in  the  dorso-cephalic  corner  are  not  represented  as 
parallel  with  the  border. 

Levator  anguli  scapulae  (Fig.  73,  §  686). — A  part  of  the  ectal  aspect  is  seen  between  the 
splenius  and  the  supraspinatus.     The  ental  aspect  of  the  whole  muscle  appears  in  Fig.  73. 

Levator  claviculcB  (§  627). — This  has  been  transected  near  its  insertion  upon  the  meta- 
cromion, and  the  metacromial  end  is  somewhat  indistinctly  seen  reflected  upon  the  spino- 
deltoideus. 

Occipito-scapularis  (§  617).— The  cephalic  attachment  is  seen  to  have  been  covered  by 
that  of  the  clavo-trapezius,  and  its  scapular  end  is  wedged  in  between  the  rliomboideus  and 
the  levator  anguli  scapulae. 

Rhomboideus  (§  620). — The  cephalic  border  is  not  satisfactorily  represented  in  this 
figure.     The  scapular  end  of  the  muscle  is  better  shown  in  Fig.  74. 

Spino-trapezius  (Fig.  66,  §  611). — The  vertebral  end  has  been  removed  altogether. 
The  scapular  end  is  lifted  a  little  so  as  to  show  its  relations  with  the  acromio-trapezius  and 
with  the  ectal  aspects  of  the  supraspinatus,  infraspinatus  and  spino-deltoideus. 

Sterno-mastoideus  (Fig.  72,  §  622). — The  removal  of  the  clavo-trapezius,  the  salivary  glands 
and  the  external  ear  has  exjMJsed  its  cranial  attachment  and  its  intersection  with  the  clavo- 
mastoideus.     Its  sternal  end  and  its  connection  with  its  platetrope  are  shown  in  Fig.  72. 

Other  Parts. — Mt.  an.  ex. — Meatus  auditorius  externus. — Its  lumen  is  exposed  by  the 
removal  of  the  concha  or  external  ear  with  the  skin. 

Mo  RHOMBOIDEUS. 

§  620.  Synonymy. — The  human  rhomboideus  major,  with,  probably  the  r.  minor  also, 
G.,  A,  375  ;  Q.,  A,  191 ;  rliomb'Jide,  S.-D.,  A,  II,  334  ;  rliombcnde,  Ch.,  A,202 ;  rhomb&idevs, 
Ch.  (Fl.),  A,  188;  rhomboideus  major,  Miv.,  B,  145. 

Figures. — Ectal  aspect  (67);  scapular  end,  ectal  aspect  (74);  scapular  end,  ental 
aspect  (75)  y  insertion  area  (44,  45). 


220  ANATOMICAL    TECHNOLOGY. 

General  Description.— Trapezoidal  in  outline  ;  from  the  caudal 
part  of  the  cermcal  dorsimeson  and  the  cephalic  part  of  the  tJio- 
racic^  to  the  vertebral  border  of  the  scapula. 

Exposure. — By  the  removal  of  the  MM.  spina-  and  acromio- 
trapezius. 

Posture. — Yentricumbent,  with  one  or  two  blocks  lengthwise 
under  the  thorax  so  as  to  permit  the  ventriduction  of  the  shoulder. 
Usually  the  body  must  be  steadied  by  cords  or  chain-hooks.  Lat- 
eriduct  the  vertebral  border  of  the  scapula  so  as  to  render  the  M. 
rJiomboideus  tense. 

Dissection.— The  ventro-cephalic  border  of  the  muscle  has  been 
exposed  by  the  reflection  of  the  occipito- scapular  is.  The  caudal 
border  may  be  seen  along  a  line  running  nearly  laterad  from  the 
4th  or  5th  thoracic  spine,  opposite  the  gleno-vertebral  angle  of  the 
scapula.  Note  that  the  texture  of  the  muscle  is  looser  than  that  of 
the  trapezia  and  that  the  caudal  border  is  thinner  than  the  ventro- 
cephalic,  excepting  the  dorso-cephalic  third  of  the  latter.  This 
muscle  may  be  safely  transected  by  cutting  ecto-entad ;  in  reflecting 
it,  note  that  the  thickest  part  is  opposite  the  1st  and  2d  thoracic 
spines. 

§  621.  Origin. — In  two  parts :  (A)  from  the  caudal  two  or  three 
fifths  of  the  cervical  supraspinous  ligament ;  in  the  latter  case  it 
includes  the  caudal  two  thirds  of  the  axial  spine,  and  thus  extends 
about  1  cm.  cephalad  of  the  acromio-trapezius ;  (B)  from  the  sides 
of  the  tips  of  the  first  four  thoracic  spines  and  from  the  interspinous 
ligaments  caudad  of  each  of  them,  excepting,  sometimes,  the  4th. 

Insertion. — At  least  two  forms  of  insertion  are  found.  The  sim- 
pler is  as  follows  (Fig.  44,  45) :  the  cephalic  three  fourths  is  attached 
by  short  tendinous  fibers  along  the  vertebral  border  of  the  scapula, 
passing  gradually  from  its  ental  to  its  ectal  margin.  The  cephalic 
half  or  third  of  this  portion  is  closely  united  with  the  insertion  of 
the  levator  anguli  scapulce.  The  caudal  fourth  is  attached  by 
fleshy  fibers  upon  the  gleno-vertebral  angle  in  apposition  with  the 
origin  of  the  teres. 

The  other  mode  of  insertion  presents  foar  divisions :  (A)  the 
cephalic  8  mm.  is  attached  by  fieshy  fibers  to  the  ental  aspect  of  the 
lev.  ang.  scap.  close  to  its  insertion  upon  the  ental  margin  of  the 
vertebral  border  of  the  scapula,  and  caudo-ventrad  of  the  insertion 
of  the  occipito-scapularis ;  (B)  the  next  6-8  mm.,  constituting  the 
thickest  part  of  the  muscle,  is  attached  by  fleshy  fibers  to  the  ental 


M,    STEENO-MASTOIBEUS.  221 

margin  of  the  vertebral  border,  opposite  the  triangular  space  at  the 
vertebral  end  of  the  mesoscapula ;  (C)  the  next  2-2.3  cm.  is  at- 
tached by  a  thin  tendon,  2-3  mm.  long,  upon  the  ectal  margin  of  the 
vertebral  border  from  opposite  the  middle  of  the  space  just  men- 
tioned, and  thus  slightly  overlapping  part  B,  to  within  8-10  mm.  of 
the  gleno-vertebral  angle  of  the  scapula ;  (D)  the  caudal  ^Q  mm. 
is  separated  from  the  rest  by  an  interval  1-5  mm.  wide,  and  is  in- 
serted by  fleshy  or  very  short  tendinous  fibers  upon  the  ectal  aspect 
of  the  gleno-vertebral  angle  in  apposition  with  the  origin  of  the 
teres.  The  scapular  end  of  the  muscle  may  be  separated  more  or 
less  readily  into  four  divisions  corresponding  with  the  parts  of  the 
insertion  just  described,  and  the  caudal  division  is  sometimes  quite 
distinct,  with  a  decided  extension  toward  the  teres. 

M.    STERNO-MASTOIDEUS. 

Remark. — This  is  strictly  a  muscle  of  the  neck,  but  is  here  described  on  account  of  its 
close  relations  with  the  muscles  of  the  shoulder  and  with  blood-vessels. 

§  623.  Synonymy. — The  sternal  part  of  the  human  sterno-deido-mastoid,  G.,  A,  357; 
Q.,  A,  1,  392  ;  sterno-mastoidlen,  S.-D.,  A,  II,  348 ;  sterno-maxillaire,  Ch.,  A,  210  ;  sterno- 
maxillarls,  Ch.  (Fl.),  A,  198;  sterno-mastoid,  Miv.,  B,  134. 

Figfures. — Lateral  aspect  of  cephalic  half  (66) ;  lateral  aspect  (67) ;  united  sternal  por- 
tions (73)  ;  sternal  portion  (73). 

§  623.  General  Description. — Tseniate,  along  the  ventro-cephalic 
border  of  the  clavo-trapezius^  from  the  prcBsternum  to  the  mastoid 
process  of  the  temporal  bone  and  the  ventral  part  of  the  crista 
lambdoidalis. 

Posture. — Latericumbent ;  a  block  transversely  under  the  neck ; 
the  head  hanging. 

Exposure. — Connect  the  angle  of  the  mouth  with  the  occipito- 
presternal  line  (§  610)  by  an  incision  corresponding  with  the  direction 
of  the  margin  of  the  upper  lip.  Note  that  the  skin  of  the  cheek, 
especially  in  old  males,  is  very  thick.  Dissect  up  both  edges  of  the 
skin  for  about  1  cm. 

The  zygoma  (Fig.  30,  ^Q>,  67)  may  be  felt  as  a  firm  bony  arch 
between  the  M.  temporalis  (Fig.  67)  dorsad,  and  the  M.  masseter 
ventrad. 

Just  caudad  of  the  zygoma  may  be  felt  the  cartilaginous  meatus 
auditorius  (Fig.  67,  Mt  au.  ex,)^  partly  embraced  by  the  small, 
pale  and  rather  loose-textured  parotid  gland  (Fig.  87, 107).  Divide 
the  meatus  close  to  the  head,  and  reflect  the  flap,  together  with  the 


222  ANATOMICAL    TECHNOLOGY. 

ear  and  parotid,  for  2-3  cm.,  taking  care  not  to  cnt  caudad  of  the 
crista. 

Then  reflect  the  ventral  flap  for  abont  the  same  distance.  In  the 
depression  just  caudad  of  the  mandibular  angle  note  the  firmer  tex- 
tured and  darker  colored  submaxillary  gland  (Fig.  66,  87).  Its 
dorsal  border  is  often  quite  firmly  attached  to  the  ventral  border 
and  ectal  surface  of  the  sterno-mastoideus.  Remove  the  gland, 
together  with  the  dense  connective  tissue  in  the  groove  between  the 
head  and  the  neck  ventrad  of  the  origin  of  the  occipito-scapularis. 

Along  the  ventral  border  of  the  space  occupied  by  the  submax- 
illary gland  is  the  Vena  jugular  is  (Fig.  101),  which  lies  upon  the 
ectal  aspect  of  the  sterno-mastoideus^  crossing  very  obliquely  from 
its  ventral  to  its  dorsal  border.  Divide  the  vein  at  the  middle  of  its 
length,  reflect  the  ends  and  free  the  surface  of  the  muscle  from  fat 
and  connective  tissue. 

Dissection. — The  dorsal  border  of  the  muscle  is  apparent  at 
about  its  middle,  where  it  was  crossed  by  the  Y.  jugularis,  and 
where  it  in  turn  crosses  the  ventral  border  of  the  subjacent  claxo- 
mastoideus.  Lift  this  border,  taking  care  not  to  include  the  fibers 
of  the  clavo-mastoideus.  A  little  ceplialad  of  the  middle  of  the 
length  of  the  muscle  dissect  from  the  dorsal  to  the  ventral  border. 

In  reflecting  the  cephalic  part,  note  that  the  ventral  border  is 
thickened  as  if  folded  upon  itself,  and  that,  at  tlie  occiput,  the  dor- 
sal border  may  overlap  the  occipito-scapularis  for  half  the  width 
of  the  latter.  In  reflecting  the  caudal  part,  note  that,  about  the 
middle  of  the  length  of  the  whole  muscle,  it  joins  its  platetrope,  the 
fibers  appearing  to  interdigitate  to  some  extent  (Fig.  72).  About 
2  cm.  cephalad  of  the  prsestemum  the  muscle  is  overlapped  by  the 
ectal  lamina  of  the  ectopectoralis, 

%  624.  Origin. — On  account  of  the  overlapping  just  mentioned, 
the  farther  dissection  of  the  sternal  end  of  the  muscle  is  better 
deferred  until  after  the  examination  of  the  ectopectoralis. 

Insertion. — The  cephalic  attachment  of  the  muscle  is  by  a  tendon 
2-7  mm.  long  which  is  inserted  upon  the  crista  lambdoidalis  laterad 
of,  and  usually  overlapping  to  some  extent,  the  origin  of  the  occip- 
ito-scapularis. The  line  of  insertion  extends  not  only  along  the 
crista,  but  also  upon  the  rather  sharp  ridge  of  the  mastoid  process^ 
which  ceases  suddenly  at  a  slight  elevation  just  dorso-caudad  of  the 
stylo-mastoid  foramen^  3-4  mm.  from  the  meatus.  The  tendon  is 
here  a  little  thicker  than  at  other  points,  and  between  it  and  the 


M,     CLAVO-MASTOIDEUS.  223 

tendon  of  the  subjacent  splenius  (Fig.  67)  there  is  sometimes  a  well- 
defined  depression. 

M.   CLAVO-MASTOIDEUS. 

§  625.  Synonymy. — The  clavicular  part  of  the  human  sterno-cleido-mastoid,  G.,  A, 
357  ;  Q.,  A,  I,  293  ;  "  cleido-mastoidien,"  S.-D..  A,  II,  333  ;  part  of  the  "  mastoido-humeraly* 
Ch.,  A,  209,  Fig.  90;  part  of  the  mastoido-humeralis,  Ch.  (Fl.),  A,  196;  part  of  the  cephalo- 
humeral,  Miv.,  B,  147  ;  deido-mastoid,  Wood,  9, 101,  Fig.  23,  "b." 

Figures.  -  Lateral  aspect  (67) ;  ventral  border  of  clavicular  part  (72). 

General  Description. — Narrow,  tseniate,  from  the  clavicle  to  the 
mastoid  process. 

Posture.  —Lat encumbent,  the  block  transversely  under  the  neck, 
and  the  head  hanging. 

Exposure. — By  the  reflection  of  the  clavo4rapezius  and  the 
sterno-mastoideus. 

Dissection. — The  dorsal  border  is  apparent  at  about  its  middle. 
Raise  it,  and  draw  the  muscle  dorsad  so  as  to  indicate  its  ventral 
border.  In  reflecting  the  cephalic  part,  note  that,  about  18  mm. 
from  the  head,  the  muscle  is  perforated  by  a  nerve,  near  which, 
entad  of  the  muscle,  lies  the  separate  lateral  half  of  the  thyroid 
body.  In  reflecting  the  caudal  part,  note  the  constant  increase  in 
width  to  the  clavicle,  that  the  V.  jugular  is  lies  mesad  of  it,  and 
usually  a  lymphatic  gland  entad  of  it,  while  its  dorsal  border  is 
attached  by  a  firm  fascia  to  the  ventral  border  of  the  levator  cla- 
viculcB. 

§  626.  Origin. — In  two  nearly  equal  parts  :  (A)  the  ventral  part 
arises,  with  the  corresponding  part  of  the  insertion  of  the  clavo-tra- 
pezius^  from  the  ventro-cephalic  border  of  the  sternal  half  or  three 
fifths  of  the  clavicle  ;  (B)  the  remainder  arises  from  the  ental  aspect 
of  the  trapezio-deltoid  raphe^  but  is  connected  with  the  scapular 
part  of  the  clavicle  by  a  strong  fascia  which  might  be  regarded 
as  a  common  tendon  of  attachment  for  the  corresponding  parts  of 
the  clavo-trapezius^  clavo-mastoideus  and  clavo-deltoideus. 

Insertion. — By  fleshy  fibers  upon  the  ventral  and  caudal  bor- 
ders of  the  mastoid  process^  and  upon  its  mesal  side. 

Remark. — Respecting  the  choice  of  origin  and  insertion  for  this 
muscle,  see  §  579. 

M.  LEVATOR  CLAVICUL^. 

§  627.  Synonymy. — "  Transverw-scapulaire,"  S.-D.,  A,  IT,  831;  "levator  daviculm" 
Wood,  9,  95,  Fig.  23,  "  e  "  ;  trachelo -acromial is,  Huxley,  A,  418 ;  levator  scapularis,  Miv., 
B,  148  ;  not  found  normally  in  man. 

Figures. — Scapular  part  (66,  67) ;  insertion  area  (45). 


224  ANAT03fICAL    TECHNOLOGY. 

Posture. — Latericumbent,  with  a  block  transversely  under  tlie 
neck.  The  posture  must  be  changed  often  and  greatly  in  the  course 
of  the  exposure  and  dissection. 

Exposure.— By  the  reflection  of  the  clam-trapezius,  sierno- 
mastoideus  and  clavo-deltoideus,  jN"ote  that,  after  the  reflection  of 
the  above  named  muscles  and  the  occipiio- scapular  is  ^  the  broad 
transverse  process  of  the  atlas  is  covered,  dorsally,  by  a  thick  mass 
of  muscle,  the  most  ectal  of  which,  the  splenius  (Fig.  67),  presents 
a  smooth  and  convex  surface.  Remove  this  mass  by  deep  incisions 
with  the  arthrotome  as  follows :  Laterad  from  the  cephalic  end  of 
the  origin  of  the  rJiomboideus  ;  then  cephalad  to  the  occiput ;  then 
laterad  close  to  the  occiput,  but  without  severing  any  of  the  muscu- 
lar attachments  along  the  crest ;  finally,  beginning  with  the  meson, 
dissect  up  the  mass  from  the  vertebrae. 

General  Description. — Narrow,  tseniate,  from  the  hasioccipital 
hone  (Fig.  57)  and  atlantal  transverse  process  or  diapopJiysis 
(Fig.  52)  to  the  metacromion  (Fig.  44). 

Dissection. — The  dorsal  border  of  the  scapular  end  has  been  indi- 
cated (§  614)  in  connection  with  the  insertion  of  the  cephalic  border 
of  the  acromio-trapezius.  Trace  it  cephalad,  and  draw  the  middle 
of  the  muscle  dorsad  so  as  to  indicate  its  ventral  border. 

In  reflecting  the  caudal  part,  note  a  lympTiatlc  gland  close  to  the 
coracoid  border  of  the  supraspinatus.  In  reflecting  the  cephalic 
part,  note  that,  a  little  caudad  of  the  atlantal  transverse  process,  its 
plane  gradually  changes  from  dorso-ventral  to  dextro-sinistral,  and 
that  there  are  signs  of  subdivision. 

Remove  the  muscles  ventrad  and  cephalad  of  the  atlantal  trans- 
verse process,  but  without  cutting  the  attachment  of  this  muscle  to 
its  ventral  surface.  Feel  for  the  prominent  auditory  bulla  just 
mesad  of  the  M.  masseter  and  the  meatus^  and  carefully  dissect 
off  the  M.  digastricus,  which  covers  it.  Avoid  the  external  carotid 
artery  which  skirts  the  meso-cephalic  border  of  the  bulla,  and  the 
Tiyoid  arcJi  (Fig.  30)  which  lies  imbedded  in  the  muscles  between 
it  and  the  artery. 

Then  use  the  tracer  to  clear  away  the  connective  tissue,  and  the 
arthrotome  to  scrape  the  ventral  surface  of  the  transverse  process 
of  the  atlas,  excepting  where  it  is  occupied  by  the  origin  of  the  lev- 
ator clamculcB,  Between  the  border  of  the  process  and  the  larynx 
and  trachea  note  and  remove  the  lateral  lobe  of  the  thyroid  hody. 


M,     DERMO-HUMERALIS.  225 

Note,  but  do  not  remove,  the  carotid  artery,  and  the  nervous  trunk 
representing  the  conjoined  NJSF.  vagus  and  sympathicus  (Fig.  107). 

§  628.  Origin. — The  larger  and  constant  head  arises  by  fleshy 
fibers  from  the  ventral  surface  of  the  atlantal  transverse  process 
along  an  oblique  line  extending  from  the  junction  of  the  process 
with  the  body  of  the  vertebra,  3-4  mm.  from  the  meson,  latero-caudad 
to  a  point  about  3  mm.  cephalad  of  the  caudo-lateral  angle  of  the 
process.  This  line  of  origin  is  6-8  mm.  long,  and  is  nearly  parallel 
with  the  oblique  meso- caudal  border  of  the  arthral  surface  in  con- 
tact with  the  axis. 

The  smaller  and  less  constant  head  is  about  3  mm.  wide  and  is 
the  more  direct  continuation  of  the  ventral  border  of  the  muscle. 
Opposite  the  latero-cephalic  angle  of  the  transverse  process  it  be- 
comes a  thin  flat  tendon  which  is  closely  applied  to  the  ventro- 
lateral aspect  of  a  muscle,  the  M.  rectus  anticus  capitis^  which 
extends  along  the  ventral  side  of  the  vertebrae,  and  is  inserted  with 
it  into  the  basioccipital  bone  nearer  the  bulla  (Fig.  57)  than  the 
meson,  and  about  midway  between  the  jugular  foramen  (Fig.  57, 
Fm.  J.)  and  the  cephalic  angle  of  the  bulla.  This,  the  occipital 
head  of  the  muscle,  is  sometimes  absent,  and  other  irregularities 
have  been  observed  in  the  cephalic  end  of  the  muscle. 

Insertion. — By  a  strong  tendon  1-2  mm.  long  and  a  little  nar- 
rower than  the  muscle,  upon  the  ectal  surface  of  the  metacromion 
(Fig.  45,  67),  close  to  its  free  border.  The  dorsal  border  slightly 
overlaps  the  ventral  border  of  the  acromio-trapezius  near  its  inser- 
tion, and  the  ventral  border  is  firmly  joined  by  a  strong  fascia  with 
the  claT)0-trapezius, 

M.  DERMO-HUMERALIS. 

§  629.  Synonymy. — "  Dermo-humeral,"  S.-D.,  A,  II,  251  ;  part  of  the  " pannicule 
charnu"  Ch.,  A,  200;  part  of  the  fleshp  pannide,  Ch.  (Fl.),  A,  186  ;  part  of  the  pannicu- 
lus  carnosus,  Miv.,  B,  136  ;  not  represented  in  man. 

Figures.— Pumeral  part,  ectal  aspect  (66,  74) ;  partly  reflected  (67,  72,  73). 

Posture. — Latericumbent,  the  ventral  region  toward  the  dis- 
sector ;  a  block  transversely  under  the  thorax,  just  caudad  of  the 
elbows. 

Exposure. — Connect  the  last  (13th)  thoracic  spinous  process 
with  the  ventrimeson  by  a  dorso-ventral  incision.  Be  careful  to 
divide  only  the  skin,  with  the  subcutaneous  fat  and  connective  tis- 
sue, together  with  a  thin  sheet  of  pale  muscular  fibers,  the  dermo- 
15 


226  ANATOMICAL    TECHNOLOGY. 

Tiumeralis^  and  avoid  cutting  the  ental,  thicker  and  darker  colored 
laiissimus  (Fig.  QQ\  the  cephalic  part  of  which  was  exposed  in  the 
dissection  of  the  spino-trapezius. 

Begin  to  lift  the  flap  at  the  dorsimeson  ;  remove  the  fat  and  con- 
nective tissue  from  the  ental  surface  of  the  dermo-Jimneralis,  and 
note  that  its  fibers  have  nearly  the  same  direction  as  those  of  the 
latissimus.  When  the  caudo-ventral  border  of  the  latissimus  is 
reached,  a  little  ventrad  of  the  middle  of  the  incision,  be  careful  not 
to  lift  with  the  skin  and  dermo-Jiumeralis^  the  thin  dorso-caudal 
margin  of  the  M.  xipM-humeralis  (Fig.  72),  a  member  of  the  pecto- 
ralis  group  of  muscles,  which  arises  at  the  meson,  and  sometimes 
adheres  quite  closely  to  the  dermo-humeralis. 

General  Description. — As  stated  by  Straus-Durckheim  (A,  I, 
251),  ^'this  muscle  covers  as  a  mantle  the  whole  thorax  and  abdo- 
men, .  .  .  but  differs  from  the  skin-muscles  proper  in  the  attach- 
ment of  one  end  to  the  skeleton;"  this  attachment,  however,  is 
only  indirect. 

Dissection. — The  cephalic  and  shorter  border  of  the  muscle  may 
be  seen  on  the  ental  surface  of  the  skin  along  a  dorso-ventral  line 
from  the  2d  or  3d  thoracic  spine  to  the  axilla.  The  caudo-ventral 
border  is  less  distinct,  but  may  be  detected  1-2  cm.  from  the  meson. 
Connect  the  two  borders  by  an  incision  3-4  cm.  from  the  brachium. 
Leave  the  caudal  portion  of  the  muscle  upon  the  skin,  but  carefully 
dissect  up  the  narrower  and  thicker  brachial  part,  freeing  both  its 
ectal  and  ental  surfaces  from  fat  and  connective  tissue.  Note  that 
it  not  only  overlies  the  corresponding  part  of  the  latissimus,  but 
that  its  ental  surface  becomes  intimately  united  with  the  ectal  sur- 
face of  that  muscle. 

§  630.  Origin. — ^From  the  skin,  along  an  oblique  line  extending 
ventro-cephalad  from  about  the  middle  of  the  length  of  the  pelvis 
upon  the  caudal  aspect  of  the  meros  as  far  as  the  knee ;  also  along 
a  line  which  is  just  laterad  of  the  dorsimeson  opposite  the  2d  or  3d 
thoracic  spine,  but  which  gradually  leaves  the  meson  as  it  extends 
caudad  to  join  the  pelvic  line  already  mentioned. 

Insertion. — From  the  broad  origin  above  described  the  fasciculi 
converge  ventro-cephalad  toward  the  caudal  aspect  of  the  brachium. 
The  muscle  becomes  narrower  and  thicker,  and  less  closely  attached 
to  the  skin.  Near  the  dorsal  border  of  the  brachium  it  joins  the 
ectal  surface  of  the  subjacent  latissimus.  The  dorsal  border,  1-1.3 
cm.  wide,  is  attached  directly  by  muscular  fibers,  but  the  remain- 


THE    HUMERUS.  227 

der  ends  as  a  thin  tendon  ranging  from  1-3  cm.  long.  The  details 
of  its  indirect  connection,  through  the  latissimus^  with  the  bicipital 
arch  (Fig.  73),  and  thus  with  the  humerus,  may  be  examined  more 
conveniently  after  the  dissection  of  the  pectorales, 

Remaxk. — This  muscle  does  not  exist  in  man,  where  the  group 
of  dermal  muscles  is  represented  only  by  the  M.  platysma  my  aides 
upon  the  sides  of  the  neck,  and  by  certain  muscles  of  the  face. 

§  631.  Explanation  of  Figures  68-71  inclusive. — These  represent  respectively  the 
cephalic  (outer),  ventral  (anterior),  caudal  (inner),  and  dorsal  (posteiior)  aspects  of  the  left 
humerus. 

A  shaded  representation  of  the  ventral  aspect  of  the  right  humerus  is  given  in  Fig.  46. 
These  four  figures  are  little  more  than  outlines  for  the  sake  of  indicating  the  attachment 
areas  and  lines  of  the  muscles  or  muscular  divisions  described  in  this  work  which  arise 
from  or  are  inserted  upon  this  bone. 

As  in  the  figures  of  the  scapula  (Fig.  43,  44),  the  lines  enclosing  origins  are  composed 
of  dots,  and  those  enclosing  insertions  of  short  dashes. 

In  order  to  place  the  figures  across  the  page,  and  so  facilitate  reference  and  comparison, 
many  of  the  parts  are  undesirably  small,  and  several  are  so  crowded  as  to  be  indistinct. 

The  attachments  are  at  least  approximately  correct  for  the  majority  of  cases,  but  con- 
siderable variation  is  to  be  expected. 

The  identification  of  the  muscles,  especially  those  of  the  pectoralis  group,  is  much 
facilitated  by  the  use  of  a  carved  wooden  model  of  the  humerus,  enlarged  4  or  5  diameters 
so  as  to  increase  both  the  attachment  areas  and  the  spaces  between  them.  Such  a  model, 
made  by  Mr.  H.  ^V.  Turner,  a  special  student,  has  been  in  use  for  several  years  in  the 
Anatomical  Laboratory  of  Cornell  University. 

The  following  features  of  the  humerus  itself  are  shown  and  sufficiently  described  in 
the  descriptions  of  Fig.  45  B  and  Fig.  46  : — 

Cn.  (canalis)  hicipitalis  (69,  70),  §§  402,  409  ;  capitellum  (69),  §  410  ;  caput  nrticulare 
(71),  §§  403,  411  ;  crista  deltoidea  (68,  69),  §  412  ;  crs.  {crista)  epicondylaris  (68,  71),  §  415  ; 
epicondylus  (69,  71),  ^  415  ;  epitrocJdea  (69,  70,  71),  §  416  ;  Fm.  {foramen)  epitrochleare 
(69.  70,  71),  §  417 ;  trochin  (69,  71),  §§  405,  420 ;  trochiter  (68,  69,  71),  §§  406,  420  ;  trochlea 
(69),  §  420. 

The  following  parts  are  not  designated  upon  these  figures,  but  may  be  recognized  from 
the  other  figures  and  descriptions  : — 

Crista  pectoralis  (Fig.  46,  §  413) ;  fossa  ulnaris  and  fossa  radialis  (Fig.  46,  §  418) :  fossa 
trochiteriana  (Fig.  45  B,  §§  404,  679). 

The  following  parts  are  not  described  elsewhere  : — 

Crista  epitrochlearis. — This  name  may  be  applied  to  the  ridge  which  extends  proximad 
from  the  epitrochlea  (Fig.  69). 

Fm.  {foramen.)  medullare—Tlie  medullary  or  nutrient  foramen  (Fig.  70).— This  opens 
upon  the  caudal  aspect  of  the  diaphysis,  at  about  the  junction  of  the  middle  and  distal 
thirds  of  the  bone.     It  points  distad  from  the  surface. 

Fs.  {fossa)  olecranalis—The  olecranon  fossa  (Fig.  71).— This  is  a  deep  and  irregular 
depression  upon  the  dorsal  aspect  of  the  extremitas  distalis.  When  the  antebrachium  is 
extended,  the  olecranon  of  the  ulna  is  received  by  it.  We  have  never  observed  a  perfora- 
tion of  the  bone  at  this  point,  as  is  sometimes  the  case  with  man. 


228 


ANATOMICAL    TECHNOLOGY. 


, ,      M,  SfiL7io~de  Itoideus, 
^  '       J  I  .  W  acro,nuo-deJtoLcLiusx    » 

P'-^u^Ai/.^       1^'  ectopectoraits^  im.  ettails.^    \  \        M.  saprasplyiGri'u^si 


^Crista  £ 
m  extensor  Jruninu. 


Fig.  68. 


M.  mlcostaUs'^ 
M.  InfraspinotUM.^ 


ftfrockiecL, 


^-epLtrochUa 


M.  xtphi-fiume rails  (A.B.CJi 
MMi'iattssimus  et  feres v    troc/itn-j^ 


\  ^TeV^  M.  ecto-,    nyn.tntcLLis  dy.c^pha.Uca:\     M.€,7i±QpettoraU^\\ 

^CapittUnrru-       pe.ctoraUs]p^e.rLtciLL^d\r.catAcLa.LLs\    d.\,  teph^tiUa.  f   \ 


Fig.  69. 


.epLtrockka^    . 
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pronator  teres 


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M.  su-prcLSpbiatus 

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Fig.  70. 


%  6 ntopecto raiis,  dv.  cauddl't'S  \ 
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Fig.  68-71.— The  Humerus. 


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M.     LATISSIMUS,  229 

^  633.  Upon  Figures  68-71  are  represented  the  insertion  areas  or  lines  of  the  following 
muscles  ;  the  list  includes  all  which  are  inserted  upon  the  humerus  :— 

Acromio  dtltoideus  (08),  §  676  ;  coracoideus,  caput  breve  (70),  caput  longum  (71),  §  668; 
ectopectoralls,  bn.  ectalis  (68,  63),  §  649 ;  ectopectoralis,  Im.  entails,  do.  caudalis  (69),  §  653 ; 
ectopectoralis,  Im.  entails,  dv.  cepJialicd  (68,  69),  §  651 ;  entopectoralis,  dv.  caudalis  (69,  70), 
§  656 ;  entopectoralis,  dv.  cep/uilica  (69,  70),  §  658 ;  infraspinatus  (68),  §  678  ;  micostalis 
(63),  §  679  ;  spino-deltoldeus  (68),  §  674  ;  suprasplnatus  (68,  69),  §  675  ;  teres  (69,  70),  §  680 ; 
xipJil-humeralis  (69),  §  660. 

As  stated  in  §  670,  the  insertion  of  the  coracoideus,  caput  hngum,  is  so  variable  that 
the  area  is  here  indicated  on  Ficr.  71  by  an  interrogation  point. 

§  634  The  origin  areas  or  lines  of  the  following  13  muscles  are  represented  upon 
Fig.  68-71  :— 

Brachial's  (68,  71),  §  692;  entotrkeps,  dv.  hrevis  (70,  71),  §  688,  dv.  caudalis  (70,  71), 
§  637,  dv.  cephallca  (71),  §  689,  dv.  intermedia  (68,  71),  §  686 ;  extensor  digitorum  com- 
munis (68,  71),  §  697  ;  extensor  minimi  (68,  71),  §  698  ;  extensor  radialis  brevior  (68),  §  696  ; 
ext.  rad.  longlor  (68,  71),  §  694 ;  extensor  vlnaris  (68),  §  699  ;  jUxor  radialis  (70),  §  702 ; 
pronator  teres  (70,  71),  j^  701  ;  supinator  long  us  (71),  §  690. 

M.    LATISSIMUS. 

§  635.  Synonymy.— Latissimus  dorsi,  Q,,  A,  1,189;  G.,  A,  374;  **  grand  dorsal,** 
S.-D.,  A,  II,  339 ;  ''grand  dorsal,"  Ch.,  A,  217,  Fig.  90  ;  great  darsal,  Ch.  (Fl.),  A,  203; 
latimmus  dorsi.  Mi  v.,  B,  137. 

Figures.— Ectal  aspect  (66,  67,  74) ;  ental  aspect  (72,  73,  75) ;  insertion  area  (69,  70) , 
transection  (99,  100). 

Posture. — Latericumbent,  tlie  venter  toward  the  dissector;  a 
block  transversely  under  the  thorax  just  caudad  of  the  elbows. 

Exposure. — Most  of  the  muscle  has  been  exposed  by  the  re- 
moval of  the  spino-trapezius  and  dermo-JiumeraUs,  and  needs  only 
to  have  its  ectal  surface  cleared.  If  the  caudal  region  of  the  body 
has  not  been  removed,  the  corresponding  part  of  the  latlssimus 
may  be  exposed  by  dividing  the  skin  and  the  dermo-Jiumeralis 
along  a  dorso-caudal  line  from  the  already  exposed  caudo-ventral 
border  of  the  latissimus  to  the  crista  ilii  (§  230,  Fig.  51)  of  the  op- 
posite side,  and  reflecting  the  flap  so  formed  across  the  dorsimeson. 

General  Description. — A  large  triangular  sheet,  covering  rather 
more  than  the  dorso-cephalic  half  of  the  abdomen  and  thorax,  ex- 
cepting so  much  of  the  latter  as  is  between  the  scapulae.  It  arises 
at  the  dorsimeson  between  the  pelvis  and  tlie  5t7i  thoracic  spine^ 
and  is  inserted  upon  the  humerus,  forming  part  of  the  bicipital 
arch  (Fig.  73). 

Dissection. — Lift  the  caudo-ventral  border  where  it  crosses  the 
7th  rib  (which  is  also  the  7th  counting  from  the  last),  and  trace  it 
both  ways  for  2-3  cm.    Trace  the  cephalic  border  from  the  vertebral 


230  ANAT03nCAL   TECHNOLOGY. 

l)order  of  tlie  scapula  along  a  dorso-ventral  line  from  the  5th  tho- 
racic neural  spine. 

Transect  the  muscle  along  a  line  between  the  7th  rib  and  the 
vertebral  border  of  the  scapula,  beginning  at  the  caudo-ventral 
border  and  alternately  lifting  and  dividing  the  successive  parts. 
Toward  the  meson,  along  a  Ijne  extending  ventro-caudad  from  the 
10th,  11th  or  12th  thoracic  spine  to  the  lateral  border  of  the  verte- 
bral muscles,  about  3  cm.  from  the  meson,  the  muscular  sheet  gives 
place  to  a  strong  fascia. 

In  reflecting  the  brachial  portion  of  the  muscle,  note  the  attach- 
ment of  the  dermo-Tiumeralis  to  its  ectal  surface  (Fig.  74),  its  close 
relations  with  the  subjacent  M.  xipM-humeralis,  and  the  presence 
of  a  lymphatic  gland  near  the  dorso-caudal  border  of  the  latter. 
Turn  the  arm  so  as  to  bring  the  convexity  of  the  elbow  dorsad,  and 
thus  expose  the  space  between  the  brachium  and  the  scapula,  and 
note  that  the  ental  surface  of  the  latissimus  is  joined,  near  its 
cephalic  border,  by  a  thick  muscle,  the  teres  (Fig.  75),  from  the 
glenoid  border  of  the  scapula,  and  that,  from  the  ectal  surface,  close 
to  the  attachment  of  the  dermo-humeralis^  there  proceeds  distad  a 
muscle,  the  epltrochlearis  (Fig.  75). 

The  details  of  the  connection  of  the  latissimus  with  the  humerus 
and  the  bicipital  arch  are  more  easily  examined  after  the  dissection 
of  the  pectoralis  group,  and  the  removal  of  the  arm  from  the  body. 

§  636.  Origin. — In  two  parts :  (A)  by  muscular  or  short  tendi- 
nous fibers  from  the  sides  of  the  tips  of  the  thoracic  spines  from  the 
4th  or  5th  to  the  10th  inclusive,  and  from  the  corresponding  inter- 
spinous  ligaments  ;  this  part  of  the  origin  is  wholly  covered  by  the 
origin  of  the  spino-trapezius ;  (B)  from  the  dorsimeson,  between 
the  10th  thoracic  spine  and  the  sacrum,  by  a  strong  triangular  ten- 
don, the  lateral  angle  of  which  corresponds  nearly  with  the  lateral 
border  of  the  vertebral  mass  of  muscles. 

Insertion. — At  the  junction  of  the  2d  and  3d  fourths  of  the  hu- 
merus, upon  its  ventral  aspect,  by  a  thick  tendon  which  forms  the 
caudal  pillar  of  the  bicipital  arcTi. 

The  detailed  description  of  the  insertion  must  include  that  of  the 
M.  teres  (§  680,  Fig.  75) ;  but  though  the  tendons  of  the  two  muscles 
are  inseparably  united,  there  are  indications  of  the  manner  of  their 
junction.  The  joint  tendon,  at  a  point  midway  between  the  hume- 
ral end  and  the  point  of  separation  of  the  two  muscles,  is  wholly 
tendinous  as  to  the  distal  fifth  of  the  caudal  surface  which  seems  to 


M,     CLA  VO-DELTOIDEUS.  231 

form  the  direct  continuation  of  the  latissimus^  while  the  remainder 
is  chiefly  muscular.  The  cephalic  surface  presents  the  opposite 
appearance,  being  muscular  as  to  its  proximal  fifth.  In  general,  it 
is  as  if  the  shorter  tendon  of  the  teres  were  applied  upon  the  longer 
tendon  of  the  latissimus  in  such  a  way  that  the  distal  border  of  the 
latter  shows  upon  the  caudal  surface  of  the  joint  tendon,  while  the 
proximal  border  of  the  former  shows  upon  the  cephalic  surface. 

The  area  of  attachment  (Fig.  71,  72)  is  about  one  seventh  of  the 
length  of  the  entire  humerus,  and  forms  an  elongated  fossa  upon 
the  caudal  surface,  near  the  ventral  border ;  its  proximal  end  is 
opposite  the  distal  end  of  the  area  of  insertion  of  the  short  head  of 
the  coracoideus, 

M.  CLAVO-DELTOIDEUS. 

§  637.  Synonymy. — The  clavicular  portion  of  the  human  deltoidevSy  G.,  A,  444 ;  Q., 
A,  1,  199  ;  "  deltoclaviculaire"  S.-D.,  A,  II,  351  ;  "portion  da  mastoido-humeral"  Ch.,  A, 
809  ;  iwrtion  of  the  mastoido-humeral,  Ch.  (Fl.),  A,  197  ;  'portion  of  the  cephalo-humeral, 
Miv.,  B,  147;  Wood,  9,101. 

Figures. — Ectal  aspect,  clavicular  end  {QQ)]  ectal  aspect  of  whole  (72,  right  side); 
ental  aspect  of  antebrachial  part  (72,  left  side). 

Posture. — Latericumbent,  the  venter  toward  the  dissector.  Se- 
cure the  arm  caudiducted  so  as  to  stretch  the  muscles  upon  the 
ventral  aspect  of  the  brachium  and  shoulder. 

Exposure. — The  proximal  end  of  the  muscle  was  exposed  dur- 
ing the  exposure  of  the  clavo-trapezius.  Connect  the  vertebro-pre- 
sternal  incision  made  in  exposing  the  trapezii  with  the  dorsal  border 
of  the  antebrachium,  at  the  junction  of  the  proximal  and  middle 
thirds,  by  an  incision  along  the  ventral  border  of  the  brachium  and 
passing  can  dad  of  the  elbow.  Reflect  both  edges  of  the  skin  for 
2-3  cm.  near  the  shoulder,  and  for  1-2  cm.  near  the  elbow. 

General  Description. — Tseniate ;  along  the  ventral  aspect  of 
the  brachium,  from  the  clamcle  to  the  ulna. 

Dissection. — Draw  the  clavicular  portions  of  the  clavo-trapezius 
and  clavo-mastoideus  away  from  the  body  so  as  to  expose  the  more 
or  less  distinct  bands — hardly  deserving  the  name  of  ligaments — 
which  pass  from  the  ends  of  the  clavicle  to  the  shoulder  and  neck. 
In  a  subsequent  dissection  of  the  parts  these  connections  may  be 
studied  in  detail  before  division.  Divide  them  and  draw  the  same 
muscles  cephalad  so  as  to  render  tense  the  clavo-deltoideus,  and 
indicate  the  general  position  and  direction  of  its  borders. 

The  caudal  border  begins  at  the  sternal  end  of  the  clavicle, 


233  ANATOMICAL    TECHNOLOGY, 

crosses  obliquely  the  subjacent  ectal  lamina  of  the  M.  ectopectoralis 
(Fig.  72,  right  side),  and,  at  the  junction  of  the  proximal  and  middle 
thirds  of  the  brachium,  is  separated  by  only  a  slender  line  of  con- 
nective tissue  from  the  cephalic  division  oii\\Q pecto-antehrachialis. 
The  cephalic  border  is  the  direct  continuation  of  the  caudal  bor- 
der of  the  clavO'trapezius^  but  is  attached  quite  firmly  to  the  strong 
fascia  covering  the  cephalic  surface  of  the  brachium.  The  muscle, 
with  the  clavicle  attached,  may  now  be  dissected  up  as  far  as  the 
ventral  border  of  the  antebrachium,  but  the  distal  half  of  the  cau- 
dal border  cannot  usually  be  separated  from  the  pecto-antebracM- 
alls  without  cutting  fibers.  The  examination  of  the  insertion  can 
be  made  more  easily  after  the  removal  of  some  other  muscles. 

§  638.  Origin. — As  stated  under  the  clavo-trapezius  (§  615),  the 
clavo-deltoideus^  viewed  from  its  ectal  surface,  is  apparently  the 
direct  continuation  of  that  muscle ;  the  two  are  really  separated 
only  by  the  transverse  raphe,  excepting  that  the  ental  layer  of  fibers 
of  the  clavo-deltoideus  arises  from  the  ventral  border  of  the  clavicle 
directly,  or — near  its  scapular  end— by  short  tendinous  fibers. 

Insertion. — At  the  ventral  border  of  the  antebrachium  the 
cephalic  border  of  this  muscle  is  firmly  connected  with  the  general 
antebrachial  fascia,  and,  at  8-10  mm.  from  the  ulna^  the  muscle 
joins  the  hracJiialis  to  be  inserted  with  it,  by  a  flat  tendon,  upon  a 
rough  and  sometimes  slightly  depressed  area  on  the  caudal  aspect 
of  the  ulna,  just  distad  of  the  greater  sigmoid  notch,  and  about 
midway  between  the  dorsal  and  ventral  borders.     See  §  693. 

Remark. — By  its  origin  this  muscle  seems  to  be  a  member  of  the  deltoid  group  of 
muscles,  but  its  insertion  associates  it,  functionally,  with  the  flexors  of  the  antebrachium. 
When  the  clavicle  is  wholly  absent,  as  with  the  horse,  etc.,  the  MM.  clavo-deltoideus,  claw- 
trapezius  and  davo-mastoideus  seem  to  form  a  single  muscle,  the  cephalo-humeralis. 

%  639.  Explanation  of  Fig.  72. — The  pectoralis  group  of  mus- 
cles, partly  dissected,  seen  from  the  ventral  aspect.  The  neck  is 
toward  the  observer.  The  right  and  left  of  the  figure  corresjjond  in 
position  with  the  right  and  left  of  the  observer  (§  ^Q). 

Preparation. — The  cat  is  dorsicumbent,  resting  upon  the  right 
side  more  than  the  left.  The  figure  includes  the  thorax  and  caudal 
part  of  the  neck,  together  with  the  arms  to  a  little  distad  of  the 
elbows.  The  arms  are  pulled  away  from  the  trunk  so  as  to  put  the 
pectoral  muscles  upon  the  stretch.  On  the  right  side,  the  borders 
of  the  muscles  have  been  defined  by  the  removal  of  the  fat  and  con- 


THE   FECTOEALIS     GROUP.  233 

nective  tissue,  and  in  some  cases  the  ectal  layers  liave  been  slightly 
displaced.  On  the  left  the  divisions  of  the  ectopectoralis  and  pecto- 
antehracMalls  have  been  reflected,  cut  short  or  wholly  removed ; 
on  this  account  the  cephalic  part  of  the  mesal  or  interpectoral 
raphe  is  drawn  dextrad  out  of  line  with  the  caudal  part,  giving 
a  somewhat  distorted  appearance  to  the  entire  figure.  The  raphe 
itself  is  too  sharply  defined. 

This  figure  fairly  illustrates  the  crossing  of  the  pectoral  elements  which  is  commented 
upon  in  §  641. 

The  figure  represents  the  condition  of  things  in  the  preparation  from  which  it  was 
taken  ;  but  in  some  respects,  especially  as  to  the  marked  subdivision  of  the  caudal  divi- 
sion of  the  entopectoralis  and  the  non-attachment  of  the  xipJii-humeralis  to  the  xiphister- 
num,  it  hardly  indicates  the  usual  arrangement. 

Bones,  etc. — Cartilago — The  first  costicartilage  (Fig.  30,  49). — The  costal  end  of  this 
just  appears  on  the  left  side. 

Cladcula  {%  423). — The  position  of  the  left  clavicle  is  nearly  inverted  with  respect  to 
its  normal  position,  on  account  of  the  reflection  of  the  clavicular  end  of  the  claw-deltoideus. 
From  its  mesal  and  lateral  ends  are  strips  of  fascia  or  thin  ligaments  passing  respectively 
to  the  praesternum  and  to  the  muscles  upon  the  scapula.  On  the  right  side  the  sternal  end 
of  the  clavicle  appears  near  the  cephalic  end  of  the  mesal  raphe. 

Costa  (Fig.  30). — Part  of  the  first  rib  appears  on  the  left  side. 

Epigastrium  (§  238). — The  name  is  written  across  this  region,  just  caudad  of  the  xiphi- 
sternum  ;  the  space  was  vacated  by  the  removal  of  the  MM.  rectus,  ectobliquus  and  other 
constituents  of  the  abdominal  parietes. 

Trochin  (Fig.  30,46,  §  430). — This,  the  "lesser"  humeral  tuberosity,  appears  on  the 
left  between  the  humeral  ends  of  the  caudal  and  cephalic  divisions  of  the  entopectoralis. 

XipMstenium  (Fig.  49,  §  436). — In  some  cases  the  xi/phi-humeralis  is  attached  to  nearly 
the  whole  length  of  the  narrower  portion  of  this  last  sternal  segment. 

Muscles. — The  following  are  not  particularly  described  in  this  work  ;  sterno-Jiyoideus, 
sterno-thyroideus,  ectobliquus  and  rectus.  The  thoracic  continuation  of  the  last  is  shown  in 
Fig.  73. 

Biceps  (§  691). — The  distal  part  of  this  appears  on  both  sides.  On  the  left  side  its  ten- 
don (tendo  bicipitis)  may  be  seen  j  ust  ventrad  of  the  trochin. 

Clavo-deltoideus  (§  651). — The  right  is  but  slightly  displaced  ;  the  left  has  been  tran- 
sected and  reflected. 

GUuo  mastoideus  (§  625)  and  clavo-trapezius  (§  615). — Tlie  edges  of  the  clavicular  ends 
of  these  muscles  are  seen  on  the  right  side  of  the  neck. 

Bermo-humeralis  (§  629). — On  the  left  side  a  fragment  of  this  is  seen  connected  with 
the  latisslmus. 

Ectopectoralis,  Im.  ectalis  (§  649). — On  the  right  this  is  partly  hidden  by  the  cephalic 
division  of  the  pecto-antehrachialis  and  the  clavo-deltoideus.  On  the  left  it  has  been  tran- 
sected very  near  the  meson,  and  the  humeral  portion  is  reflected. 

Ectopectoralis,  Im.  entalis,  dv.  caudalis  (§  653). — Only  part  of  this  appears  on  the  right. 
The  humeral  portion  of  the  left  has  been  reflected,  and  part  of  it  removed  so  as  to  leave  it 
shorter  than  the  di\  cephalica. 

Ectopectoralis,  Im.  entalis,  dv.  cephalica  (§  651). — On  the  right  it  is  entirely  hidden  by 
the  ectal  lamina  ;  the  left  has  been  treated  like  the  caudal  division,  excepting  that  the 
reflected  humeral  end  is  left  longer. 


2U 


ANATOMICAL    TECHNOLOGY. 


Entopedoralis,  do.  caudalis  (§  656). — The  riglit  humeral  portion  is  hidden.  The  left 
was  separable  into  two  divisions. 

Mntopectoralis,  do.  cephalica  (§  658).— On  the  right  little  of  this  is  visible.  On  the  left 
it  is  almost  wholly  exposed. 

EpitrocJdearis  (§  681).— The  left  is  entire,  passing  from  the  latissimus  to  the  elbow, 
where  it  is  associated  with  the  pecto-antebrachicdis.  On  the  right  side  is  seen  the  reflected 
distal  half. 


ctavo  trapezius 

iideus 

chLvo-maatoiiABM 


Fig.  72. — The  Pectokalis  Group  op  Muscles,  Partly  Dissected. 


Latissimus  (§  635). — A  fragment  of  the  right  is  visible.  The  left  has  the  appearance 
of  passing  ectad  of  the  hiceps ;  in  reality,  however,  most  of  it  passes  entad  of  the  biceps, 
and  what  appears  to  be  the  continuation  of  the  latissimus  is  the  tendon  of  the  xiphi-hume- 
ralis  which  passes  entad  of  the  caudal  division  of  the  entopectoralis. 

Pecto-antehrachialis,  dv.  cephalica  (§  646),  do.  caudalis  {%  647). — These  are  shown  entire 
on  the  right,  but  on  the  left  they  have  been  removed  excepting  the  distal  ends. 

Sterno-mastoideus  (§  622). — The  sternal  ends  of  both  are  shown,  including  the  mesal 
raphe  formed  by  the  interdigitation  of  their  fibers. 

Supinator  longus  (§  690). — Part  of  this  appears  on  the  right. 

Supraspinatus  (§  675). — This  is  more  fully  shown  in  Fig.  73,  74. 


PECTORALIS    GROUP,  235 

Triceps  (§§  687-689). — The  caudal  or  ectal  aspect  of  the  entotriceps  appears  on  both 
sides,  but  the  divisions  are  not  defined. 

Xiphi-humeralis  (§  660). — On  the  right  the  sternal  part  is  shown  but  not  named.  On 
the  left,  its  course  entad  of  the  entopectoral's  is  indicated  by  the  broken  lines,  and  part  of 
its  humeral  end  is  seen.  Usually  this  muscle  is  more  intimately  connected  with  the 
xiphisternum. 

PECTORALIS  GROUP. 

§  640.  General  Remark. — The  two  pectoral  muscles  of  man, 
ectopectoraUs,  ''pectoralis  major,"  and  entopectoralis,  ''pectoralis 
minor,"  are  represented  in  the  cat  by  several  mnscles  to  which 
Straus-Durckheim  and  others  have  applied  distinct  names.  Most 
of  these  divisions,  however,  may  be  recognized  as  parts  of  two 
masses,  an  ectal  or  superficial,  arising  nearer  the  cephalic  end  of 
the  sternum,  and  extending  laterad  to  the  diapTiysis  of  the  hume- 
rus, and  an  ental  or  deep,  arising  from  the  caudal  part  of  the  ster- 
num, and  extending  later o-cepTialad  to  the  Tiead  of  the  bone.  The 
former,  representing  the  ectopectoraUs,  tends  to  subdivide  into 
superposed  lamince ;  the  latter,  representing  the  entopectoralis, 
tends  rather  toward  a  division  into  parallel  fasciculi.  See  §  572, 
Humphrey,  E,  110,  and  Wilder,  20,  306. 

§  641.  CrosHing  of  the  Pectoral  Elements. —^^cluding  the  M.  pecto-antelrachialis, 
which  is  inserted  upon  the  antebrachium,  the  pectoral  mass  may  be  roughly  described  as 
a  series  of  four  superposed  laminae  crossing  one  another  in  such  a  way  that  the  cephalic  in 
origin,  is  distal  in  insertion,  while  the  caudal  in  origin  is  proximal  in  insertion. 

The  ectal  lamina  of  the  M.  ectopectoraUs  (Fig.  72)  arises  from  the  prsesternum  and  ceph- 
alad  of  it,  and  is  inserted  upon  the  middle  third  of  the  humerus.  The  ental  lamina,  as  a 
whole,  arises  from  the  cephalic  third  of  the  sternum,  and  is  inserted  upon  the  proximal 
three  fifths.  The  M.  entopectoralis,  as  a  whole,  arises  from  the  entire  mesosternum,  and  is 
inserted  upon  the  proximal  third.  Finally,  the  M.  xiphi-humeralis  arises  from  or  near  the 
xiphisternum,  and  is  inserted  upon  the  head  and  neck  of  the  humerus. 

It  follows  from  this  arrangement  that  the  general  direction  of  the  fibers  of  the  first  por- 
tion is  nearly  transverse  ;  that,  in  the  natural  attitude  of  the  arm,  for  a  part  of  their  course 
at  least,  the  fibers  of  the  last  portion  run  nearly  parallel  with  the  meson  ;  while  the  direc- 
tions of  the  other  two  portions  are  intermediate. 

A  somewhat  similar  relation  exists  between  the  less  distinctly  separable  regions  of  the 
human  ectopectoraUs  as  described  by  Gray  (A,  400)  and  Quain  (A,  I,  193). 

The  insertion  lines  of  the  two  laminae  of  the  ectopectoraUs  are  nearly  parallel,  but 
almost  meet  at  their  distal  ends  (Fig.  69).  If  they  were  continuous,  they  might  be  de- 
scribed as  a  single  line  folded  upon  itself,  and  their  tendons  would  be  strictly  comparable 
with  the  tendon  of  the  human  pectoralis  major  as  described  by  Gray  and  Quain. 

§  642.  The  Pectoral  Complexity. — In  the  cat  there  may  be  recognized  eight  or  nine 
elements  of  the  pectoral  mass,  more  or  less  independent  as  to  origin  or  insertion  or  both. 
In  man,  the  M.  entopectoralis  (P.  minor)  is  distinct,  and  the  M.  ectopectoraUs  is  more  or 
less  readily  in  different  subjects  separable  into  two  or  three  portions,  whose  origins  and 
insertions,  however,  are  nearly  or  quite  continuous. 

It  may  be  said,  therefore,  that  the  provision  for  separate  and  independent  movement 


236  ANATOMICAL    TECHNOLOGY. 

by  means  of  the  pectoral  muscles  is  twice  as  grreat  in  the  cat  as  in  man.  This  will  hardly 
surprise  those  who  have  watched  a  kitten  at  play,  or  a  cat  in  any  kind  of  vigorous  action. 
It  must  be  remembered,  however,  that  this  superior  complexity  of  the  muscles  acting  upon 
the  biachium,  and  thus  upon  the  limb  as  a  whole,  does  not  confer  peculiar  powers  upou 
the  distal  segment,  and  no  one  would  regard  the  cat's  manus  as  equal  to  that  of  man.  In 
the  quadruped,  the  specialization  is  proximal  and  the  distal  parts  are  relatively  simple ; 
with  the  bimanous  biped,  the  muscles  acting  upon  the  arm  as  a  whole  are  comparatively 
simple  and  in  what  may  be  regarded  as  a  generalized  condition,  but  the  projection  of  the 
brachium  from  the  thorax  confers  great  freedom  of  movement,  while  the  distal  muscles 
are  more  distinct  and  independent  than  in  the  cat. 

Those  who  are  disturbed  that  any  parts  of  a  cat  should  be  described  as  more  complex 
than  the  corresponding  human  organs  should  compare  the  stomach  and  brain  of  man  with 
the  same  parts  of  the  pig,  sheep  and  porpoise, 

§  643.  Caution. — Excepting  the  muscles  especially  related  to 
the  vertebral  column,  there  are  probably  none  more  difficult  of  dis- 
section than  the  pectorales.  This  is  due  in  part  to  the  number  and 
extent  of  the  individual  variations  which  have  so  far  made  it  impos- 
sible to  provide  directions  to  meet  all  cases,  but  chiefly  to  the 
intrinsic  complexity  of  superposition  and  attachment. 

The  student  should  proceed  with  great  caution,  follow  the  direc- 
tions and  descriptions  as  closely  as  possible,  repeat  the  dissection 
upon  the  opposite  side,  and  make  careful  notes  and  drawings  of  all 
peculiarities.  < 

§  644.  Exposure. — As  with  the  trapezius  group,  it  is  usually 
more  convenient  to  expose  all  of  the  pectorales  by  lifting  a  single 
flap  of  skin. 

Connect  the  antebrachial  end  of  the  incision  made  in  exposing 
the  clavo-deltoideus  with  the  free  border  of  skin  left  in  exposing  the 
dermo-Jiumeralis  and  latissimus^  or  with  the  epigastrium  (Fig.  72). 
Begin  with  the  skin  already  raised  from  the  ventral  aspect  of  the 
brachium,  and  reflect  the  flap  just  circumscribed  across  the  ventri- 
meson.  To  cut  as  nearly  as  possible  in  the  direction  of  the  fibers, 
the  flap  may  be  grasped  at  first  by  the  angle  near  the  shoulder,  but 
later  by  its  caudal  margin.  Great  care  must  be  taken  to  avoid 
injuring  the  subjacent  muscles. 

M.  PECTO-ANTEBRACHIALIS. 

§  645.  Synonymy.—"  Pecto-antebracMal"  S.-D.,  A,  II,  352  ;  "  sterno-aponeurotique," 
Ch.,  A,  247  ;  sterno-aponeuroticus,  Ch.  (Fl.),  A,  232  ;  part  of  "  pectoralis,  part  1,'*  Mi  v.,  B, 
145  ;  not  normally  represented  in  man. 

Figures. — Ectal  aspect  of  both  divisions  (72,  right  side  ;  distal  ends  (72,  left  side). 

General  Description. — In  two  divisions,  cephalic  and  caudal^ 
from  the  median  raplie  at  the  prcesternum  and  3d  mesosterneber 


M.     PECTO-ANTEBRACniALIS.  237 

respectively,  to  the  dorsal  border  of  the  antehracMum  near  the 
elbow. 

Posture.— Dorsicumlbent,  the  head  toward  the  dissector ;  a  hlock 
under  the  shoulders  so  that  the  head  and  neck  hang  down.  . 

§  646.  Dv.  Cephalica. — ^Dissection. — The  cephalic  border  has 
been  indicated  during  the  dissection  of  the  clavo-deltoideus^  to 
which  it  is  attached  excepting  at  the  ends.  Trace  it  for  2-3  cm. 
both  ways  from  the  middle.  Then  feel  upon  the  meson,  about 
3  cm.  from  the  tip  of  the  prsesternum,  for  the  elevation  corresponding 
with  the  first  sternal  node,  or  for  the  attachment  thereto  of  the  sec- 
ond costicartilages.  Laterad  from  that  point  runs  a  white  line, 
which  marks  the  caudal  margin  of  the  muscle.  Toward  this  line 
dissect  up  the  muscle  from  its  cephalic  border,  at  about  the  mid- 
dle of  the  length  of  the  latter,  and  transect. 

In  reflecting  the  mesal  part  of  the  muscle,  note  its  close  attach- 
ment to  the  subjacent  ectopectoralis^  and  that  it  joins  its  platetrope 
by  a  median  raphe.  The  distal  part  of  the  muscle  is  much  more 
easily  separable  from  the  subjacent  muscle,  but,  about  1  cm.  ven- 
trad  of  the  level  of  the  antebrachium,  its  caudal  border  is  joined 
by  the  caudal  division  of  the  muscle.  At  this  point  the  muscular 
fibers  of  both  divisions  are  replaced  by  tendinous  fibers. 

The  tendon  thus  formed  seems  to  be  continuous  with  the  general 
antebrachial  fascia,  but,  if  this  fascia  be  divided  along  a  line  cor- 
responding with  the  cephalic  border  of  the  muscle,  the  tendon  may 
be  traced  across  the  caudal  surface  of  the  antebrachium  and  found 
to  terminate  upon  the  dorsal  aspect  of  the  ulna.  The  examination 
of  the  details  of  the  insertion  may  be  deferred  until  after  the  dissec- 
tion of  the  caudal  division. 

Origin. — From  a  median  raphe  common  to  it  and  its  platetrope, 
and  extending  the  whole  length  of  the  prsesternum,  excepting, 
sometimes,  its  caudal  or  cephalic  1-2  mm. 

Insertion. — By  tendinous  fibers  along  the  distal  third  of  the 
oblique  caudal  border  of  the  subcutaneous  surface  near  the  proxi- 
mal end  of  the  dorsal  aspect  of  the  ulna.  The  cephalic  border  of  the 
tendon  is  closely  attached  for  part  of  its  length  to  the  caudal  border 
of  the  clavo-deltoideits,  and  its  caudal  border  is  continuous  with  the 
fibers  forming  the  tendon  of  the  caudal  division  of  the  muscle. 

§  647.  Dv.  Caudalis.— Posture  and  Exposure  as  with  the 
cephalic  division.    The  muscle  is  very  slender  and  closely  attached 


238  ANATOMICAL    TECHNOLOGY. 

to  the  neigblboring  muscles,  so  that  its  isolation  is  not  always  easy. 
Sometimes  it  is  absent  altogether. 

Dissection. — The  distal  part  of  the  cephalic  border  has  heen 
indicated  as  united  with  the  caudal  border  of  the  cephalic  division. 
It  is  here  1.5-3  mm.  wide,  but  widens  gradually  as  it  crosses  the 
axilla  and  nears  the  meson. 

At  3-5  cm.  from  the  meson,  it  leaves  the  border  of  the  cephalic 
division,  and  becomes  attached  with  equal  closeness  to  the  caudal 
border  of  the  ental  lamina  of  the  ectopectoraUs^  which  it  accompa- 
nies, until  it  reaches  the  meson  at  the  3d  mesosterneber,  about  the 
middle  of  the  length  of  the  sternum,  exclusive  of  the  xiphisternum. 

§  648.  Origin. — By  very  short  tendinous  fibers,  from  the  meson 
of  the  3d  or  4th  mesosterneber,  just  caudad  of  the  origin  of  the  ental 
layer  of  the  ectopectoralis.  Sometimes  the  origin  on  one  side  is 
just  caudad  of  that  on  the  other.  At  the  meson  its  width  is  10-15 
mm.,  but  it  narrows  greatly  toward  the  distal  end.  The  caudal 
border  of  the  distal  end  is  connected  with  the  epitrocJilearis, 

M.  ECTOPECTORALIS. 

§  649.  Synonymy.— The  human  pectoraUs  major,  G.,  A,  399  ;  Q.,  A,  II,  193  ;  "  large 
pectoral,"  S.-D.,  A,  I,  342. 

Exposure. — By  the  reflection  of  the  MM.  clamdeltoideus  and  pecto-antebrachialis. 

LAMINA    ECTALIS. 

Synonymy. — "  Le  premier  chef  du  large  pectoral"  S.-D.,  A,  T,  343  ;  pectoraUs,  part  2^ 
{in  part),  Mi  v.,  B,  146. 

Figures.— Part  of  ectal  aspect  (72,  right  side) ;  ental  aspect  of  humeral  end  (72,  left 
side)  ;  insertion  line  (68, 69). 

General  Description. — Wide,  tseniate,  from  the  ventrimeson^  at 
and  cephalad  of  t\\Q  prce sternum,  to  the  middle  third  of  the  ventral 
border  of  the  Jiumerus. 

Dissection. — The  caudal  border  extends  almost  directly  laterad 
from  i\ie  pr  ester  no  meso  sternal  node,  where  its  mesal  end  underlies 
the  mesal  end  of  the  caudal  border  of  the  cephalic  division  of  the 
M.  pecto-antehracJiialis.     Lift  it  with  great  care  at  about  the  middle. 

The  cephalic  border  lies  nearly  parallel  with  the  caudal,  at  a 
'distance  of  2-3  cm.,  and  extends  almost  directly  laterad  from  the 
point  where  the  caudal  end  of  the  sterno-mastoideus  (Fig.  72)  passes 
entad  of  the  pectoral  mass.  In  well-injected  specimens  this  border 
is  indicated,  at  about  the  middle  of  its  length,  by  the  disappear- 
ance, entad  of  it,  of  an  artery  which  has  emerged  from  the  thorax 
and  curved  over  the  cephalic  border  of  the  pectoral  mass. 


M.     ECTOPECTORALIS.  239 

Lift  the  cephalic  border  at  its  middle  and  relax  the  parts  so  as  to 
permit  dissection  entad  of  the  muscle  from  one  border  to  the  other  ; 
then  transect. 

la  reflecting  the  mesal  end  of  the  muscle,  cut  an  artery  and 
nerve  which  emerge  from  the  subjacent  ental  layer^  and  note  that, 
near  the  meson,  the  cephalic  border  curves  cephalad.  The  ental 
surface  of  the  lateral  part  of  the  muscle  is  often  so  closely  joined 
with  the  subjacent  muscle  that  there  is  danger  of  cutting  fibers. 
The  tracer  should  be  used  in  tearing  the  connective  tissue  until  the 
bone  is  reached. 

§  650.  Origin. — From  a  median  raphe  common  to  it  and  its 
platetrope  ;  the  caudal  half  or  three  fifths  of  the  raphe  is  attached 
to  the  presternal  keel,  the  remainder  is  continuous  with  the  line  of 
union  of  the  caudal  portion  of  the  MM.  sterno-mastoidei. 

Insertion. — The  middle  of  the  length  of  the  line  of  insertion  cor- 
responds closely  with  the  middle  of  the  length  of  the  humerus,  but 
the  insertion  includes  rather  more  than  a  third  of  the  length  of  the 
bone.  Its  distal  end  is  almost  in  line  with  the  middle  of  the  distal 
end  of  the  bone,  but  its  proximal  end  is  nearly  midway  between 
the  ventral  and  cephalic  aspects.  The  caudal  border  of  the  line  of 
insertion  is  well  defined,  but  the  cephalic  is  not  so  clearly  separable 
from  the  insertions  ot  the  spino-deltoideus  and  hracMalis^  and  a 
strong  fascia  sometimes  extends  proximad  from  the  border  of  the 
muscle  toward  the  trochiter. 

LAMINA  ENTALIS,   DV.    CEPHALICA. 

§  651.  Synonymy. — *'  Le  second  chef  du  large  pectoral,  sa  partie  ant^rieure,"  S.-D., 
A,  II,  343  ;  pectoralis,  part  5,  "  subclavicular  part"  Miv.,  B,  147. 

Figures. — Sternal  end  (72,  left  side) ;  humeral  end,  reflected  (73,  left  side) ;  insertion 
area  (68,  69). 

General  Description. — Narrower  and  thicker  than  the  ectal 
layer ;  15-18  mm.  wide ;  from  the  prcBsternum  and  raphe  to  the 
proximal  fourth  of  the  cephalic  side  of  the  humerus. 

Dissection. — The  artery  and  nerve  mentioned  (§  649)  as  passing 
from  the  ental  to  the  ectal  layer  of  the  ectopectoralis  usually  pene- 
trate the  former  through  a  narrow  interval  about  one  third  of  the 
distance  from  the  meson  to  the  humerus.  This  interval  usually 
marks  the  line  of  separation  between  the  cephalic  and  caudal  divi- 
sion of  the  ental  lamina  of  the  ectopectoralis.  Mesad  of  the  inter- 
val, the  plane  of  separation  is  at  a  right  angle  with  the  surface  of 


240  ANATOMICAL    TECHNOLOGY. 

the  muscle,  but  laterad  of  it  the  plane  becomes  oblique,  with  a 
dorso-cephalic  direction  wliich  is  more  marked  nearer  the  humerus. 
Transect  by  an  ecto-ental  incision  opposite  the  artery. 

In  reflecting  the  sternal  part,  note  the  close  union  of  the  ental 
surface  near  the  meson  with  the  ectal  surface  of  the  sterno-mastoU 
deus.  In  reflecting  the  humeral  part,  note  that,  excepting  at  the 
caudal  border,  the  muscular  fibers  cease  along  the  ventral  margin 
of  the  trochiter. 

§  652.  Origin.— The  caudal  two  thirds  is  from  the  lateral  sur- 
face of  the  prsesternum  cephalad  of  the  attachment  of  the  first  costi- 
cartilage ;  the  cephalic  third  from  the  median  raphe  and  from  the 
ectal  surface  of  the  steTno-mastoideus. 

Insertion. — Along  a  curved  line  upon  the  cephalic  surface  of  the 
proximal  fourth  or  fifth  of  the  humerus  (Fig.  68,  69).  The  line  of 
insertion  begins  3-4  mm.  proximad  of  the  proximal  end  of  the  inser- 
tion of  the  ectal  lamina^  and  sometimes  very  slightly  ventrad  of  it. 
The  distal  two  thirds  of  the  line  extend  dorso-proximad  to  a  point 
just  ventrad  of  the  slight  elevation  {Tbcl,  micostale^  see  M.  mico- 
stalls),  distad  of  the  Fs.  trochiteriana  (Fig.  45,  B),  where  it  usually 
turns  slightly  ventrad  so  that  the  proximal  third  forms  an  angle  of 
20-30  degrees  with  the  rest.  The  line  ceases  about  3  mm.  from  the 
proximal  border  of  the  trochiter  at  the  edge  of  the  insertion  of  the 
M,  supraspinatus. 

LAMIKA  ENTALIS,  DV.   CAUDALIS. 

§  653.  Synonymy. — "Ze  second  chrf  du  large  pectoral,  sa  partie  poster ieure"  S.-D,, 
A,  II,  343  ;  pectoralis,  part  2  {in  part),  Miv.,  B,  143. 

Figures. — Part  oi  ectal  aspect  (71,  right  side) ;  humeral  end,  reflected  (72,  left  side)  ; 
insertion  line  (69). 

General  Description.— The  widest  and  longest  portion  of  the 
ectopectoralis,  excluding  of  course  the  pecto-antebracMalis ;  from 
the  cephalic  part  of  the  sternum  to  the  second  and  third  fifths  of 
the  ventral  border  of  the  humerus. 

Dissection. — The  cephalic  border  has  been  indicated  during  the 
dissection  of  the  cephalic  division,  and  the  caudal  border  during  the 
dissection  of  the  caudal  division  of  the  pecto-antebracMalis.  Lift 
both  borders,  but  dissect  up  the  middle  of  the  muscle  from  the 
cephalic  toward  the  caudal  border,  using  the  tracer  and  the  handle 
of  the  scalpel  so  as  to  avoid  cutting  the  subjacent  muscles ;  then 
transect,  and  reflect  both  ends  until  bone  is  reached. 


M.    ENT0PECT0RALI8.  241 

§  654.  Origin. — By  fleshy  fibers,  from  the  lateral  border  of  the 
pr ester nal  Iceel^  and  from  the  first  mesosterneber  and  jpart  of  the 
second,  thus  filling  the  interval  between  the  origin  of  the  cephalic 
division  and  that  of  the  jpecto-antebracliialis,  do.  caudalis. 

Insertion. — Along  a  line  occupying,  approximately,  the  second 
and  third  fifths  of  the  ventral  border  of  the  humerus,  thus  ventrad 
of  the  lines  of  insertion  of  the  cephalic  division,  and  of  the  ectal 
lamina.  The  insertion  is  somewhat  variable  in  detail,  but  a  simple 
form  is  the  following:  The  cephalic  half  continues  fleshy  to  the 
bone,  while  the  caudal  half  is  inserted  by  a  thin  tendon  3-7  mm. 
long.  The  proximal  end  of  the  line  of  insertion  is  nearly  opposite, 
but  2-3  mm.  ventrad  of,  the  distal  end  of  the  line  of  insertion  of  the 
cephalic  division,  and  the  distal  end  is  close  to  the  distal  end  of  the 
line  of  insertion  of  the  ectal  lamina. 

M.  ENTOPECTORALIS. 

§  655.  Remark. — The  remainder  of  the  pectoral  mass  forms  at  least  three  divisions 
which  are  suflaciently  distinct  in  origin  or  insertion  to  warrant  separate  descriptions,  but 
which,  perhaps,  are  all  parts  of  what  may  be  regarded  as  a  large  representative  of  the 
"  pectoralis  minor"  of  man  (§  572). 

Thes3  muscular  divisions  are  very  variable  in  number,  form,  connection  with  each  other 
and  osseous  attachment.  In  respect  to  size  there  are  marked  differences  between  individ- 
uals ;  in  young  or  feeble  cats,  the  masses  may  be  not  only  thin,  but  more  or  less  sxibdivided, 
while  in  adult  or  robust  animals,  they  are  sometimes  almost  continuous  with  each  other. 

Exposure. — So  much  as  was  not  concealed  by  the  M.  ectopecto- 
rails  is  covered  by  a  dense  layer  of  connective  tissue  which  must 
be  removed. 

DV.   CAUDALIS. 

§  656.  Synonymy. — "Le  premier  chef  du  grand  pectoral  "  S.-D.,  A,  II,  341  ;  pectoraliSf 
part  3  {in  part),  Miv,,  B,  147. 

Figures. — The  ectal  aspect  (72,  both  sides);  humeral  end,  reflected  (73);  insertion 
line  (69,  70). 

General  Description. — A  thick  band,  from  the  6t7i  mesosterne- 
her  and  sometimes  the  xipMsternum  to  the  proximal  half  or  two 
fifths  of  the  ventral  border  of  the  humeral  diaphysis. 

Dissection. — The  line  of  separation  between  the  cephalic  and 
caudal  divisions  is  about  midway  of  the  width  of  the  whole  mass, 
at  about  3  cm.  from  the  humerus ;  it  coincides  nearly  with  a  line 
drawn  from  the  surgical  neck  of  the  bone  in  the  direction  of  the 
fibers  of  the  muscle.  The  degree  of  separation  varies  greatly,  and 
16 


242  ANATOMICAL    TECHNOLOGY, 

sometimes  one  or  both  of  tlie  divisions  show  signs  of  subdivision. 
In  the  specimen  figured  (Fig.  72),  the  cephalic  division  presents  two 
well-marked  subdivisions. 

Near  the  humerus  the  interval  between  the  two  divisions  is 
usually  wide,  but  toward  the  sternum  the  cephalic  border  of  the 
caudal  overlaps  the  caudal  border  of  the  cephalic  division,  and 
sometimes  their  separation  cannot  be  effected  without  cutting  fibers. 
At  the  sternum,  however,  the  overlapping  sometimes  hardly  exists. 

The  caudal  border  has  been  exposed  during  the  dissection  of  the 
latissimus  and  dermO'Tiumeralis^  whose  humeral  ends  are  connected 
with  this  muscle  at  the  bicipital  arcJi  (Fig.  73) ;  but  the  sternal  half 
of  this  border  is  closely  united  with  the  cephalic  border  of  tlie 
xipM-humeralis^  which  it  overlies  in  its  humeral  half.  The  xijjM- 
Jiumeralis  may  be  recognized  by  its  loose  and  wide  origin  at  the 
epigastrium.  Carefully  disengage  the  two  muscles  at  their  crossing, 
then  transect  the  caudal  division  of  the  entopectoralis, 

§  657.  Origin. — By  fleshy  or  short  tendinous  fibers  from  the 
border  of  the  last  2  or  3  mesosternebrse,  and  sometimes  from  the 
cephalic  part  of  the  xiphisternum,  and  from  the  intervening  nodes. 

Insertion. — Variable  and  complex,  and  not  easily  described, 
excepting  in  connection  with  the  other  elements  of  the  bicipital  arch. 
At  about  3  cm.  from  its  attachments  to  the  ventral  border  of  tlie 
humerus  the  caudal  border  is  connected  with  the  latissimus,  and  its 
ental  aspect,  along  an  oblique  line  passing  proximo-cephalad,  is 
sometimes  united  with  the  thin  tendon  of  the  xipM-Jiumeralis.  For 
the  sake  of  distinctness,  this  union  may  be  severed  close  to  the 
ental  surface,  some  fasciae  passing  from  the  caudal  border  of  the 
tendon  to  the  surface  of  the  M.  Mceps  may  be  removed,  and  the 
extent  of  the  true  insertion  may  be  seen  more  distinctly. 

Like  that  of  the  caudal  division  of  the  ental  layer  of  the  ecto- 
pectoralls^  the  insertion  is  partly  muscular  and  partly  tendinous. 
The  line  of  attachment  is  about  3  cm.  long,  and  extends  from  the 
base  of  the  trochiter  along  the  ventral  border  of  the  humerus  to  a 
point  near  the  junction  of  the  second  and  middle  fifths  of  the  length 
of  the  whole  bone,  and  opposite  the  junction  of  the  muscular  and 
tendinous  parts  of  the  insertion  of  the  caudal  division  of  the  ental 
lamina  of  the  ectopectoralis.  The  proximal  third  or  two  fifths  of  the 
insertion  is  fleshy,  the  rest  is  a  thin  tendon  about  1  cm.  long. 


M.    ENTOPECTORALIS.  243 


DV.    CEPHALICA. 


§  658.  Synonyniy. — **  Sterna  trochitbrien"  S.  D.,  A,  II,  337;  pectoralis,  part  3  (in 
part),  Miv.,  B,  147. 

Figures. — Ectal  aspect  (72,  left  side);  humeral  end,  reflected  (73) ;  insertion  area (68, 
69,  70). 

General  Description. — A  thick  band,  mucli  widened  at  the 
sternum ;  from  all  the  mesosternebrcB^  excepting  the  first  and  sixth 
— OY  fifth  and  sixth — and  from  the  intervening  Siudi  terminal  nodes ^ 
to  the  head  of  the  humerus. 

Exposure. — Both  borders  have  been  exposed,  the  cephalic  by 
the  reflection  of  the  ectopectoralis^  the  caudal  by  the  reflection  of 
the  caudal  division  of  the  entopecioralis. 

Dissection. — The  humeral  end  must  be  reflected  with  great  care, 
and  the  preliminary  examination  should  be  made  with  the  tracer 
rather  than  with  the  scalpel.  Particular  pains  should  be  taken  to 
avoid  cutting  or  breaking  a  slender  tendon  which  sometimes  extends 
from  the  cephalic  border,  close  to  the  humerus,  to  the  coracoid 
process  of  the  scapula  (Fig.  73,  Tn,  x.). 

The  ectal  fibers  of  the  muscle  cease  at  the  supraspinatus,  and 
seem  to  be  inserted  upon  it,  but  the  coracoid  margin  of  the  latter 
muscle  may  be  dissected  up  for  1-5  mm. ;  there  will  be  exposed 
a  tendinous  continuation  of  the  entopectoralis^  which,  as  to  its 
cephalic  half,  cannot  be  separated  farther  from  the  tendon  of  the 
supraspiriatus  without  cutting  the  tendinous  fibers. 

§  659.  Insertion. — At  the  border  of  the  overlapping  supraspi- 
natus  the  fleshy  part  of  the  present  muscle  is  replaced  by  a  tendon 
which  is  attached  to  the  caudal  aspect  of  the  trochiter,  and  along  its 
ventral  border  ;  this  attachment  is  in  line  with  the  insertion  of  the 
caudal  division,  and  terminates  1-2  mm.  from  its  proximal  end. 
The  caudal  half  or  third  of  this  tendon  is  thin ;  the  rest  is  thick  and 
fused  with  the  ental  surface  of  the  tendon  of  the  supraspinatus  so 
that  the  respective  areas  of  attachment  can  be  ascertained  only 
approximately.  The  latter  muscle,  however,  is  on  the  ectal  side, 
and  occupies  the  crest  and  cephalic  aspect  of  the  trochiter. 

In  addition  to  the  tendon  of  direct  insertion,  a  slender  band 
sometimes  extends  from  the  cephalic  border,  just  at  the  junction  of 
the  muscle  and  the  tendon,  and  is  attached  to  the  border  of  the 
coracoid  process  between  its  tip  and  the  prominent  coracoid  lip  of 
the  glenoid  fossa.    This  tendon  probably  represents  the  coracoid 


244r  ANATOMICAL    TECHNOLOGY. 

insertion  of  the  entire  entopedoralis  in  some  monkeys  and — more 
commonly — in  man.  As  to  the  frequency  of  the  humeral  insertion 
of  the  human  M.  entopectoralis,  see  Macalister,  Proc.  Roy.  Irish 
Acad.,  X,  142. 

M.  XIPHI-HDMERALIS. 

§  660.  Synonymy. — "  Le  second  chef  du  grand  pectoral,"  S,-D.,  A,  II,  341  ;  pectoralis, 
part  4,  Miv.,  B,  147. 

Fig'ures. — Part  of  ectal  aspect  (72) ;  humeral  end,  reflected  (73) ;  insertion  spots  (69). 

Exposure. — By  the  reflection  of  the  other  portions  of  the  pec- 
toral mass. 

General  Description. — ^The  longest  and  most  slender  member 
of  the  pectoralis  group  ;  from  the  median  raphe  at  the  epigastrhim 
to  the  proximal  end  of  the  humerus.  The  length  of  the  cephalic 
border  is  sometimes  20  cm.,  while  the  width  at  the  middle  is  only 
4  mm. 

Dissection  and  Origin. — The  caudal  border  was  exposed  during 
the  dissection  of  the  MM.  latisslmus  and  d^ermo-humeralis  /  the 
cephalic  border  during  the  dissection  of  the  caudal  division  of  the 
M.  eniopectoralis.     Transect  the  muscle  near  the  middle. 

In  reflecting  the  proximal  part,  note  that,  1-2  cm.  from  the 
meson,  the  loose  connective  tissue  between  it  and  the  thoracic  parie- 
tes  is  sometimes  replaced  by  a  Arm  tendinous  attachment  to  the  8th 
costal  cartilage  and  to  the  fascia  covering  the  M.  rectus  ;  the  mus- 
cular fibers  cease  at  about  the  same  point,  and  the  thin,  wide  tendon 
is  connected  with  its  platetrope  by  a  median  raphe,  the  position  of 
which,  as  regards  the  xiphisternum,  is  quite  variable. 

§  661.  Insertion. — The  humeral  connections  are  complex  and 
variable.  In  passing  the  latissimus,  it  is  usually  connected,  by 
tendinous  fibers,  with  the  ental  surface  of  that  muscle,  then,  indi- 
rectly, with  the  eniopectoralis  and  the  other  elements  of  the  bicipital 
arch.  Just  beyond  this  connection  the  narrow  muscle  is  replaced 
by  a  tendon  which  usually  widens  as  it  nears  the  humerus.  In  the 
broad  sheet  so  formed  may  usually  be  detected  three  more  or  less 
distinct  bands  with  attachments  as  follows  (Fig.  QQ,  71,  73) :  (A) 
upon  the  bicipital  border  of  the  trochin,  just  cephalad  of  the  inser- 
tion of  the  M.  subscapularis  ;  (B)  and  (O)  just  caudad  of  the  inser- 
tions of  the  cephalic  and  caudal  divisions  of  the  eniopectoralis.  As 
a  whole,  therefore,  the  tendon  spans  the  bicipital  groove. 


BICIPITAL    ARCH,  245 


ARCUS  BTCIPITALIS— THE  BICIPITAL  ARCH  (Fig,  73). 

662.  This  name  is  given  to  the  tendinous  arch  through  which 
passes  the  M.  biceps  (Fig.  73,  75).  In  man,  normally,  the  ectopecto- 
ralis  passes  ectad  of  the  biceps,  while  entad  of  it  pass  the  tendons  of 
the  latissimus  and  teres.  In  the  cat,  as  in  the  Mammals  generally, 
there  is  a  union  of  the  ental  with  the  ectal  muscles  so  as  to  form  a 
complete  arch  over  the  biceps.  The  ectal,  or  cephalic,  pillar  of  the 
arch  is  formed  by  the  caudal  division  of  the  entopectoralis  ;  the 
ental,  or  caudal,  pillar,  by  the  teres  and  latissimus,  while  the 
xipM-humeralis  and  derrao-Tiumeralis  are  connected  with  one  or  the 
other  pillar,  with  the  muscles  composing  them,  or  with  the  convex- 
ity of  the  arch  itself. 

Explajiation  of  Fig.  73. — The  ental  aspect  of  the  muscles  about 
the  left  shoulder,  and  the  ectal  aspect  of  the  MM.  serratus  magnus 
and  levator  anguli  scapulce. 

Preparation. — After  the  dissection  and  reflection  or  removal  of 
the  muscles  of  the  trapezius  and  pectoralis  groups,  and  of  the  other 
muscles  already  described  as  connecting  the  soma  with  the  arm  and 
shoulder  girdle,  the  arm  and  scapula  were  turned  dorsad. 

Certain  muscles  {scaleni)  not  described  herein  have  been  wholly 
removed  from  the  neck  and  cephalic  part  of  the  thorax,  and  of  the 
M.  ectobliquus  (abdominis)  there  is  left  little  more  than  the  first  six 
digilations.  There  are  thus  exposed  the  M.  rectus  with  its  wide, 
thin  tendon,  and  parts  of  the  costal  cartilages  7-8,  with  the  inter- 
vening MM.  inter  CO  stales. 

Bones,  etc. — A  reus  bieipitalis,  with  its  cephalic  and  caudal  pillars  (Clm.  cephaZica  and 
eaudalis)—T]ie  bicipital  arch  (§  662). — This  is  seen  to  embrace  the  M,  biceps.  There  ia 
considerable  variety  in  the  mutual  relations  of  its  constituents.  In  the  preparation  fig- 
ured, the  M.  latissimus  might  be  said  to  enter  into  the  composition  of  both  pillars,  and  the 
M.  dermo-humeralis  does  not  directly  reach  the  arch  at  all, 

Costa  and  cartilago  (§§  441,  443). — The  first  rib  is  exposed  and  the  name  is  written 
thereon.  The  sternal  ends  of  the  eighth,  ninth  and  tenth  ribs  are  seen  near  the  cut  bor- 
der of  the  M.  ectohliquus.  The  first  costicartilaije  affords  insertion  to  the  tendon  of  the  M. 
rectus,  and  parts  of  the  seventh  to  the  tenth  appear  between  the  margins  of  the  MM.  rectus 
and  ectobliquus  ;  elsewhere  their  position  is  indicated  by  dotted  lines. 

Diapophyses  cermcales — The  transverse  processes  of  the  cervical  vertebras  (§  481). — 
These  are  numbered  1-7,  but  no  name  has  been  written  near  them.  Note  the  gradual 
increase  in  the  extent  of  their  bifurcation  toward  the  caudal  end  of  the  series. 

Pre.  {Processus)  coracoideus — The  coracoid  process  of  the  scapula  (Fig.  43,  44,  45  A ; 
§§  389.  400:. 


ANATOMICAL    TECHNOLOGY, 


Tn,  X. — The  tendinous  slip  from  the  border  of  the  cephalic  division  of  the  M.  ectopecto- 
ralis  to  the  coracoid  process  (§  659). 

Trachea — windpipe  (Fig.  89). — The  transverse  lines  indicate  merely  the  general 
appearance  of  this  tube,  and  not  the  number  of  its  rings. 

Xvphi&ternum  (Fig.  49,  72,  §  426). 


iV.  tt'^T  rt&-s  etvpata  rts 


crTi 


^^.t(^ 


Fig.  73. — ENTAii  Aspect  of  the  Left  Shoulder  Muscles,  and  Ectal  Aspect  of 

THE    MM.    SERRATUS-MAGNUS  AND   LEVATOR  ANGVLI  SCAPUL.'E. 


Muscles. — The  following  are  not  particularly  described  ;  the  numbers  placed  after  the 
names  designate  the  other  figures  in  which  they  appear : — 

8plenius  (67) ;  sterno-thyroideus  (72) ;  rectus  (72) ;  ectobliquus  (72)  ;  intercostalis. 

Biceps  {%  691). — The  proximal  tendon  is  seen  passing  entad  of  the  lij^ament  which 
spans  the  Ganalis  bicipitnlis  (Fig.  46  and  45,  B),  and  emerging  again  nearer  the  Pre.  cora- 
coideus ;  it  is  not,  however,  inserted  into  it,  but  upon  the  Tuherculum  bieipit/ile  (Fig.  45,  A). 

Coi'acoideus  (%  668). — Only  the  caput  breve  is  seen,  arising  from  the  coracoid  process 
and  passing  to  the  neck  of  the  humerus.     The  caput  longum  appears  in  Fig.  75. 


M,     SEERATUS    MAGNUS.  24? 

jDermo-humeralis  (§  629) — A  i)art  of  tliis  is  seon  to  pass  to  the  ectal  aspect  of  tLe  M. 
latissimus. 

EntopeetGi'alis^  do.  caudalts  (§  656). — As  in  Fig.  73,  which  was  taken  from  the  same 
preparation,  this  division  presents  a  well-marked  subdivision. 

Eiito'pectoralis,  dv.  cephalicd  (§  658). — Thicker  than  the  caudal  division,  this  is  inserted 
chiefly  upon  the  trochiter,  but  here,  as  in  some  other  cases,  a  slender  tendon  {Tn.  x.)  passes 
to  the  coracoid  process. 

Lntissimus  (§  635). — The  ectal  aspect  was  presented  in  Fig.  66  and  67 ;  hero  are  seen 
the  ental  surface  and  its  connections  with  the  arcus  blcipiialis  and  the  M.  teres. 

Levator  anguU  scapulcE  i^  666). — The  general  appearance  of  the  muscle  is  fairly  indi- 
cated, but  the  removal  of  the  other  soft  parts  from  the  line  of  origin  lias  given  the  proxi- 
mal end  the  look  of  having  been  cut  off  The  proximo-cephalic  angle  also  extends  some- 
what too  far  cephalad.  The  interval  bstween  it  and  the  serratus  magnns  was  artificially 
produced.  The  two  muscles  are  evidently  parts  of  the  same  general  muscular  lamina,  but 
there  are  sufficient  practical  reasons  for  treating  of  them  separately. 

Bterno-mastoidens  (^  623). — This  is  better  shown  in  Fig.  72. 

Suhsrapiilaris  (§  670). — Especially  noteworthy  are  the  appearances  of  its  continuity 
with  the  adjacent  muscles,  serratus  magnns,  lecator  anguli  scapnlcB,  teres  and  supraspina- 
tus.     Its  tendon  of  insertion  is  crossed  by  the  coracoideus. 

Siipraspimitus  {%  615). — Between  this  and  tha  humeral  part  of  the  suhscapularis  is  the 
triangular  interval  mentioned  in  the  dissection  of  the  coracoideus  (§  668). 

Teres  (§  680). — As  in  the  other  figures,  the  word  major  has  been  inadvertently  added. 

Xiphi-huraeralia  (§  660). — The  humeral  end  is  reflected  like  the  two  divisions  of  the 
entopectoraUs. 

Occipito-scapularis  (§  617). — Its  ventral  margin  is  seen  to  thicken  caudad. 

M.   SERRATUS  MAGNUS. 

§  664.  Synonymy. — The  human  serratus  magnus,  G.,  A,  402,  Q.,  A,  1, 196  ;  "grand 
denteU"  [thoracic  portion],  S.-D.,  A,  II,  335  ;  grand  dentele,  Cli.,  A,  250  ;  great  serratus, 
Ch.  (F].),  A,  236  ;  serratus  magnus,  Miv.,  B,  145. 

Figures. — Ectal  aspect  (73)  ;  scapular  end  (75) ;  insertion  area  (43). 

Posture. — Latericumbent ;  the  venter  toward  the  dissector;  a 
block  transversely  under  the  thorax  just  caudad  of  the  elbows. 

Exposure. — For  the  complete  exposure  of  this  muscle  it  is  neces- 
sary to  reflect  all  the  muscles  thus  far  enumerated,  excepting  the 
sternO'Onastoldeus ;  also  to  remove  the  larger  part  of  the  thoracic 
portion  of  the  M.  ectohliquus  "  external  oblique  muscle  of  the 
abdomen"  (Fig.  73),  and  to  remove  or  partly  displace  the  thoracic 
portion  of  the  M.  rectus  and  some  other  muscles  upon  the  cephalic 
region  of  the  thorax. 

Lift  the  elbow  so  that  the  brachium  rests  at  a  right  angle  with 
the  side  of  the  neck.  Dissect  out  the  fat  and  connective  tissue  thus 
exposed  between  the  shoulder  and  scapula  and  the  thorax,  then 
divide  and  reflect  the  axillary  vessels  and  nerves.  This  will  permit 
the  whole  arm,  with  the  scapula,  to  be  turned  dorsad  so  as  to  expose 


248  AiXATOMICAL    TECHNOLOGY. 

the  lateral  wall  of  the  thorax.  Sometimes  there  will  be  found  a 
slender  muscle  extending  from  the  muscles  covering  the  ventral 
surface  of  the  cervical  vertebrae  to  the  M.  teres  which  lies  along 
the  glenoid  border  of  the  scapula. 

General  Description.— A  thick,  trapezoidal  muscle,  from  all 
the  ribs  and  cartilages^  excepting  the  last  3  or  ^,  to  the  caudal 
three  fifths  of  the  vertebral  border  of  the  scapula.  Its  cephalic  bor- 
der is  continuous  with  the  caudal  border  of  the  levator  anguli  scap- 
ulce,  with  which,  indeed,  it  seems  to  form  a  single  muscle.  The 
independence  of  the  two  muscles  in  man  results  from  the  absence  of 
so  much  of  the  lev.  ang.  scap,  as — in  the  cat — arises  from  the  last 
three  cervical  vei^brse. 

Dissection. — Kear  the  vertebral  end  of  the  first  rib  note  the 
emergence  of  an  artery  and  nerve.  Extending  caudad  from  this 
point  note  the  sliglitly  raised  border  of  a  long,  flat  muscle,  one  of 
the  Scaleni  ;  divide  this  at  the  fourth  rib,  and  reflect  the  two  ends, 
to  the  9th  or  10th  costal  cartilage  and  to  the  cervical  muscles  re- 
spectively. Nearer  the  ventrimeson  lies  another,  and  wider,  ribbon- 
shaped  muscle,  the  rectus  thoracis.,  the  thoracic  continuation  of  the 
rectus  abdominis.  Eeflect  this  muscle,  together  with  the  strong 
fascia  between  it  and  the  ventrimeson,  cephalad  as  far  as  the  1st 
rib,  and  caudad  to  the  9th  or  10th. 

Now  turn  the  arm  ventrad  so  as  to  expose  the  ental  surface  of 
the  combined  serratus  magnus  and  levator  anguli  scapulce.  Dis- 
sect up,  or  divide,  the  rather  dense  fascia  which  extends  from  the 
dorso-caudal  and  dorso-cephalic  borders  upon  the  neck  and  thorax. 
Lift  the  arm  from  the  thorax  so  as  to  put  the  whole  muscle  upon 
the  stretch,  and  examine  the  ectal  surface  along  a  line  extending 
from  the  point  of  emergence  of  the  artery  and  nerve  above  m.en- 
tioned — corresponding  with  the  vertebral  attachment  of  the  first 
rib— to  the  vertebral  border  of  the  scapula  at  or  near  the  junction 
of  its  coracoid  and  middle  thirds,  and  opposite  the  vertebral  end 
of  the  mesoscapula. 

If,  along  this  line,  runs  the  principal  branch  of  the  artery,  the 
division  of  the  entire  mass  into  a  caudal  part,  the  serratus  magnus, 
and  a  cephalic  part,  the  legator  anguli  scapidcB,  can  usually  be 
made  without  cutting  many  fibers  ;  but  in  some  cases  it  may  be  bet- 
ter to  leave  the  muscles  connected.  Note,  in  either  case,  that  the 
M.  serratus  presents,  in  its  thoracic  half,  divisions  corresponding  to 
the  ribs,  while  the  other  muscle  is  continuous. 


M.    SERRATUS    MAGNUS,  249 

Divide  the  connective  tissue,  sometimes  quite  firm,  whicli  unites 
these  subdivisions,  and  then  transect  the  muscle  itself  along  a  curved 
line  about  3  cm.  from  the  scapula.  For  greater  ease  of  examining 
the  attachments  of  the  subdivisions,  continue  the  interval  just  cau- 
dad  of  the  4th  rib  to  the  cut  edge  of  the  muscle.  In  reflecting  the 
two  parts  thus  formed,  note  the  passage  of  nerves  and  vessels  to 
them  from  the  intercostal  spaces.  The  muscle  is  usually  tender, 
and  the  tracer  should  be  used  rather  than  the  knife  in  clearing 
away  the  connective  tissue  at  the  attachments  of  the  subdivisions. 

§  QQ5,  Origin. — A  line  drawn  through  all  the  origins  describes 
about  the  lifth  of  a  circle,  extending  from  the  middle  of  the  1st  rib 
to  the  middle  of  the  9th  or  lOtli.  The  4th  subdivision  extends  almost 
directly  dorsad,  the  first  and  last  extend  dorso-caudad  and  dorso- 
cephalad  respectively,  while  the  intermediate  ones  vary  in  direction 
according  to  position. 

The  first  subdivision  arises  from  the  1st  rib  along  nearly  or  quite 
the  whole  of  its  caudal  border ;  tow^ard  the  sternal  end  it  is  over- 
lapped to  some  extent  by  the  attachment  of  the  scalenus  above 
mentioned ;  the  2d,  from  the  2d  costal  cartilage  1-2  mm.  from  its 
union  with  the  rib,  and  sometimes  by  a  short  tendon ;  the  3d  and 
4th,  from  similar  points  upon  their  respective  ribs  or  just  at  the 
point  of  union  of  the  ribs  and  cartilages ;  the  5th,  at  the  point  of 
junction  ;  tlie  6th,  7th  and  8tli,  from  their  respective  ribs,  at  grad- 
ually increasing  distances  from  their  junctions  ;  the  9th,  at  about 
2  cm.  from  the  junction.  The  lines  of  attachment  of  the  first  and 
the  last  coincide  very  nearly  with  the  axis  of  the  ribs  ;  those  of  the 
next  four  are  nearly  at  right  angles,  while  those  of  the  remaining 
three  are  oblique.  A  10th  subdivision,  from  the  10th  rib,  some- 
times occurs.    It  should  be  carefully  looked  for. 

Insertion. — The  scapular  attachment  is  continuous,  but  in  two 
parts  :  (A)  the  caudal  two  to  three  fifths  is  by  a  short  tendon  along 
the  ental  edge  of  the  vertebral  border  of  the  scapula ;  (B)  the 
remainder  is  by  fleshy  flbers  upon  a  triangular  area  near  the  ver- 
tebral border  of  the  subscapular  fossa,  10-15  mm.  long  and  4-8  mm. 
wide.  The  wider  end  of  this  attachment  is  opposite  the  vertebral 
end  of  the  mesoscapula,  and  is  continuous  with  the  insertion  of  the 
levator  anguli  scapulce. 


250  AJ>rA  TOMICAL     TECHNOL  OQT. 


M.  LEVATOR  ANGULI  SCAPULA. 

§  666.  Synonymy. — The  human  Imator  anguli  scapulce,  G.,  A,  376,  Q.,  A,  I,  192 ; 
"grand  denteW  [the  cervical  portion],  S.-D.,  A,  II,  335;  angalalre  de  Vomoplat,,  Ch.,  A, 
203  ;  ang'ilar  muscle  of  the  scapula  Ch.  (Fl.),  A,  189  ;  levator  a/iguli  scapulce,  Miv.,  B,  145. 

Figures. — Ectal  aspect  (73)  ;  scapular  end  (75) ;  insertion  area  (43). 

Posture  and  Exposure. — These  are  the  same  as  with  the  serra- 
tus  magnus^  excepting  that  the  block  may  be  under  the  neck,  and 
the  muscles  {scaleni)  covering  the  series  of  ventral  tubercles  of  the 
diapophyses  of  the  cervical  vertebrae  (Fig.  53)  must  be  removed. 

General  Description. — Thick,  trapezoidal,  just  cephalad  of  the 
M.  serraius  magnus^  from  the  diapophyses  of  the  3d-7th  cervical 
vertebrce  to  the  subscapular  surface  of  the  scapula  close  to  the 
vertebral  border. 

Dissection. — After  the  division  of  the  serratus  magnus,  this 
forms  the  only  union  between  the  arm  and  the  trunk.  Note  its 
compactness  as  compared  with  the  muscle  just  named,  although 
sometimes  the  vertebral  end  shows  signs  of  subdivision.  Transect 
it  at  the  middle. 

§  687.  Origin. — By  fleshy  fibers  from  the  rounded  ends  of  the 
dorsal  tubercles  of  the  transverse  processes  of  all  the  cervical  verte- 
brae excepting  the  atlas  and  axis,  and  from  the  ligaments  between 
the  tubercles.  Entad  of  tlie  attachment  will  be  seen  the  shining 
tendons  of  the  M,  plagio-antobliquus  cermcalis.  The  line  of 
origin  is  about  6  cm.  long. 

Insertion. — The  scapular  attachment  is  by  fleshy  fibers  upon  a 
triangular  area  about  15  mm.  long  by  5-10  mm.  wide  (Fig.  43).  This 
area  is  continuous  with  the  area  of  insertion  of  the  serratus  mag- 
nus^  but  tiie  apex  points  in  the  opposite  direction,  that  is,  toAvard 
the  coracoid  border  of  the  scapula.  The  ental  surface  sometimes 
receives  the  insertion  of  the  occipito- scapular  is  (§  617). 

Remark. — The  arm,  with  the  scapula  attached,  has  now  been  separated  from  the  trunk, 
and  may  be  dissected  on  a  smaller  tray.  After  reviewing  the  insertions  of  the  muscles  so 
far  examined,  the  dissector  may  remove  them  to  withiu  1-2  cm.  of  their  attachment. 

M.  CORACOIDEUS. 

§  668.  Synonymy.— The  human  coraco-lyracMalis,  G.,  A,  407,  Q.,  A,  I,  204;  ^' coram 
brachial:'  S.-D.,  A,  II,  343  ;  "  coracobrachial"  Ch.,  A,  268  ;  coi'aco-humeralis  Oh.  (Fl.),  A, 
254 ;  coraco-brachialis,  Miv.,  B,  148. 

Figures.— Caj)^^  Ireve  (73) ;  caput  longvm  (75) ;  insertion  areas  (70,  71). 


31.     CORACOIDEUS.  251 

Posture. — The  bracliium  forms  nearly  a,  right  angle  with  both 
the  scapula  and  the  antebrachium.  Place  the  arm  upon  its  cephalic 
surface,  let  the  antebrachium  and  manus  rest  against  the  rim  of  the 
tray  toward  the  dissector,  and  place  a  block  Hatwise  under  the 
scapula  and  shoulder  so  that  the  brachium  forms  an  angle  of  about 
45  degrees  with  the  tray. 

Exposure. — Remove  the  fascia,  fat,  connective  tissue,  vessels 
and  nerves  upon  the  caudal  aspect  of  the  shoulder  and  bracliium. 
In  doing  this,  watch  very  carefully  for  the  slender  tendon  (of  the 
caput  tongum,  Fig.  75),  which  extends,  in  some  cases,  nearly  the 
wliole  length  of  the  brachium  ;  use  the  tracer  more  than  the  knife, 
and  remove  nothing  until  sure  that  the  tendon  is  not  included. 

General  Description. — This  muscle  consists  of  two  parts  {caput 
longum  and  cp.  hi^eve)^  so  distinct  that,  if  they  were  larger,  they 
probably  would  be  regarded  as  two  muscles  (§  573).  They  arise 
from  the  coracoid  process  of  the  scapula  and  are  inserted  into  the 
humerus  near  its  proximal  and  distal  ends.  Both  parts  are  so 
small  as  to  be  easily  overlooked. 

Dissection. — Feel  for  the  coracoid  process  in  the  triangular  inter- 
val at  the  head  of  the  humerus  between  the  distal  ends  of  the  sub- 
scapular is  and  suprasplnatus  (Fig  73,  75) ;  the  tip  of  the  process 
is  just  at  the  border  of  the  former  muscle  near  the  apex  of  the  inter- 
val. Carefully  lift  the  border  of  the  subscapularis  with  the  forceps, 
and  use  the  tracer  and  scalpel  to  dissect  between  it  and  the  slender 
coracoideus.  The  latter  lies  upon  the  capsule  of  the  joint  and 
sometimes  adheres  quite  firmly  to  it. 

Separate  the  connections,  when  they  exist,  with  the  tracer,  and 
divide  the  muscle  so  as  to  follow  the  course  of  the  shorter  and  more 
fleshy  part  (caput  hreve)  from  the  coracoid  process  to  the  surgical 
neck  of  the  humerus.  The  dissection  of  the  longer  and  more  slen- 
der caput  longum  should  be  done  almost  wholly  with  the  tracer, 
and  the  delicate  tendon  should  not  be  pulled  in  tracing  it  toward 
the  distal  end  of  the  humerus. 

§  669.  Origin. — The  common  origin  of  the  two  heads  from  the 
tip  of  the  coracoid  process  is  by  a  tendon  about  1  mm.  long. 

Insertion. — The  short  head  is  inserted  by  fleshy  fibers  upon  the 
caudal  surface  of  the  surgical  neck  of  the  humerus  ;  the  length  of 
the  area  of  insertion  is  approximately  equal  to  half  the  distance 
from  its  proximal  end  to  the  proximal  end  of  the  humerus,  and  the 
width  equals  half  the  length.     The  ventral  margin  of  the  area  of  its 


252  ANATOMICAL    TECHNOLOGY. 

insertion  is  well  defined,  but  the  dorsal  margin  is  in  contact  with 
the  area  of  insertion  of  the  proximal  division  of  the  internal  head  of 
the  triceps,  and  sometimes  fasciculi  cross  from  one  muscle  to  the 
other. 

The  long  head  is  more  often  absent  than  present :  it  is  not  men- 
tioned by  Mivart,  and  its  existence  in  the  cat  is  denied  by  Meckel 
(A,  VI,  281).  Of  the  cases  observed  by  us,  no  two  were  alike.  The 
fleshy  portion  usually  leaves  the  short  head  at  about  its  middle, 
and  is  2-3  cm.  long.  Its  tendinous  continuation  is  sometimes  fila- 
mentary and  disappears  among  the  intermuscular  fascia ;  some- 
times it  is  larger  and  divides,  one  portion  joining  the  tendon  of  the 
epiirocJilearis  and  the  other  inserting  upon  the  humerus  near  the 
Fm.  epitrochleare ;  more  often  this  last  is  the  only  attachment,  but 
the  precise  point  varies  so  much  that  the  area  which  was  observed 
in  one  case  is  indicated  on  Fig.  71  by  an  iTderrogation  point. 

M.  SUBSCAPULARIS. 

§  670.  Synonymy. — The  human  subscapularis,  G.,  A,  404,  Q.,  A,  I,  203  ;  "  soiis-scap- 
ulaire,"  S,-D.,  A,  II,  345  ;  "  sous-scapulaire,"  Ch.,  A,  266  ;  suhscapularis,  Ch.  (Fl.),  A,  252; 
svbseapularis,  Miv.,  B,  148. 

Figures. — Ental  aspect  (73,  75) ;  origin  area  (43)  ;  insertion  area  (70,  71). 

Posture. — The  same  as  for  the  coracoideus.  The  muscle  is 
already  fully  exposed. 

General  Description.— Thick,  subtriangular,  from  most  of  the 
subscapular  fossa  of  the  scapula  to  the  trochin  of  the  humerus. 

Dissection. — In  addition  to  the  loose  fascia  previously  removed, 
the  free  surface  of  the  suhscapularis  is  covered  by  a  firmer  fascia 
which,  in  places,  adheres  to  the  muscle.  Complete  the  removal  of 
connective  tissue  and  fat  from  the  triangular  intervals  near  the  gle- 
noid ends  of  the  glenoid  and  coracoid  borders  of  the  muscle,  and 
between  them  and  the  supraspinatus  and  teres  respectively.  Note 
that  the  coracoid  interval  is  twice  the  length  of  the  other,  and 
extends  about  two  fifths  of  the  length  of  the  muscle. 

Manipulate  the  muscle  so  as  to  indicate  the  direction  of  the  fas- 
ciculi, and  note  that  the  central  portion  of  the  muscle  is  hidden  near 
the  glenoid  end  of  the  scapula  by  the  converging  glenoid  and  cora- 
coid portions. 

Transect  the  muscle  to  the  bone  by  an  incision  connectiug  the 
two  borders  at  the  apices  of  the  intervals  above  mentioned  ;  bisect 
the  vertebral  end  of  the  muscle  and  reflect  the  two  sides,  noting  the 


31.     SUBSCAPULARIS.  253 

extent  and  manner  of  connection  between  the  muscle  and  the  bono  ; 
then  reflect  the  humeral  end,  noting  its  close  attachment  to  the  cap- 
sule of  the  shoulder  joint. 

§  671.  Origin. — By  fleshy  fibers  from  the  subscapular  fossa, 
excepting :  (A)  the  oblong  area  near  the  vertebral  border  which 
gives  insertion  to  the  levator  anguli  scapulce  and  serratus  magnus ; 
(B)  an  irregular  quadrilateral  area  near  the  glenoid  angle  of  the 
bone,  the  vertebral  limit  of  which  coincides  nearly  with  the  position 
of  a  vascular  foramen  about  1  cm.  from  the  lip  of  the  glenoid  fossa. 
In  addition  to  this  general  fleshy  origin  from  the  periosteum  lining 
the  subscapular  fossa,  the  muscle  has  at  least  two  lines  of  tendinous 
attachment  along  the  slight  ridges  which  converge  toward  the  gle- 
noid angle. 

Insertion. — By  a  strong  flat  tendon  upon  the  dorsal  border  of 
the  trochin  of  the  humerus  at  the  margin  of  the  arthral  surface. 

§  672.  Explanation  of  Fig.  74. — The  cephalic  (outer)  aspect 
of  the  left  brachium  and  antebrachium,  with  the  ectal  muscles  of 
the  scapular  region. 

Preparation. — After  examination  of  the  MM.  serratus  magnus 
and  levator  anguli  scapulce,  the  arm  with  the  scapula  was  detached 
from  the  trunk  by  the  transection  of  those  muscles. 

The  spino-deltoideus  and  acromio-deltoideus  have  been  tran- 
sected and  reflected. 

Bones,  etc. — Acromion  (Fig.  44,  §  392). — As  seen  in  Fig.  G7,  the  tip  of  this  process 
coincides  with  the  acromial  margin  of  the  M.  acromio-deltoideus ;  but  the  muscle  is  here 
reflected  so  as  to  hide  it,  and  the  name  has  not  been  connected  therewitli  by  a  dotted  line. 

Capitellum  radii  (§§  220,  410). — This  enlargement  of  the  proximal  end  of  the  radius  is 
shown  but  not  named  in  Fig,  30.  Its  position  hero  is  nearly  indicated  by  the  beginning 
of  the  name. 

Epicondylus  (Fig.  30,  68,  69,  71,  §  415). — The  position  is  nearly  indicated  by  the  first 
letter  of  the  name. 

Olecranon  (Fig.  30,  §  230). — This  proximal  process  of  the  ulna  forms  the  angle  of  the 
elbow. 

Trochiter  (Fig,  30,  46,  68,  §  405). — This  has  been  exposed  by  the  removal  of  the  M, 
clavo-deltoideus  (Fig.  66).     By  inadvertence  it  is  marked  ce. 

Muscles. — The  following  have  been  suflScieutly  described  in  connection  with  tho 
figures  whos3  numbers  are  placed  in  parentheses  : — 

Dermo-humerali8  (66,  67,  72,  73),  ^  629  ;  latissimus  [QQ,  67,  72,  73),  §  635 ;  rhomhoideus 
(67),  §  620  ;  supraspimitus  (67),  §  675  ;  teres,  "  teres  major,"  (67),  §  680. 

Acromio-deltoideus  {%  676)  and  spino  deltoideus  (§  674).— These  two  muscles  have  been 
transected  and  reflected.  The  name  of  the  former  is  written  across  tho  scapular  end 
of  both. 


254 


ANATOMICAL    TECHNOLOGY. 


Bleeps  (§  691).— After  transection,  the  distal  part  of  tins  was  left  in  place  ;  tlie  proximal 
part  is  hidden,  but  appears  in  Fig.  75. 

Brachialis  {%  692).— The  somewhat  thin  ectal  margin  of  this  flexor  of  the  antebrachium 
gives  no  adequate  idea  of  its  size  and  the  extent  of  its  origin  area  (Fig.  68). 

Extensor  digitorum  communis  (§  697). — 
The  origin  areas  of  this  and  of  the  ex.  minimi 
(§  693)  and  ex.  ulnaris  (§  699)  are  closely 
group'id  on  tha  epicondylus,  and  their  bodies 
form  a  compact  mass. 

Extensor  {carpi)  radialls  longlor  (§  694)  and 
ex.  radialls  hremor  (§  693). — The  name  is 
written  upon  the  body  of  the  former,  but  the 
latter  is  only  partially  visible,  and  its  name  is 
written  along  the  side  of  the  supinator  lonijus. 

Flexor  vlnarls  (§  702). — The  name  is  writ- 
ten along  the  side  of  the  muscle. 

Meditrlceps — The  "  long,  middle  or  scapu- 
lar head  of  the  triceps"  (§  682).— The  tendon 
of  this  strong  muscle  is  comparatively  small 
and  is  partly  hidden  by  the  micostalis  (here 
called  teres  minor).  The  body  of  the  muscle 
is  also  partly  hidden  by  the  ectotrlceps. 

Micostalis — "Teres  minor"  (§  679).— In 
the  undissected  arm  this  insignificant  muscle 
is  hidden  by  the  acromlo-deltoideus  and  spino- 
deltoideus. 

Spino  deltoideus  (§674). — See  acromio-del- 
toideus  above. 

Supinator  longus  (§  690). — The  M.  of  the 
name  rests  upon  the  proximal  end  of  this  mus- 
cle, which  is  seen  to  emerge  between  the  MM. 
biceps  and  brachialis. 

Teres  minor — Micostalis. — See  above. 

M.  SUPRASPINATUS. 

§  673.  Synonymy. — The  human  supra, 
spinatus,  G.,  A,  405,  Q.,  A,  I,  200 ;  *'  svs-epi- 
neux,"  S.  -D  ,  A,  II,  336  ;  "  sns-epineux,  Ch., 
A,  285;  supraspinatus,  Ch.  (Fl.),  A,  251; 
supraspinatus,  Miv.,  B,  148. 

Figures. — Ectal  aspect  (67,  74) ;  part  of 
ental  aspect  (73,  75) ;  origin  area  (44) ;  inser- 
tion area  (68,  69,  70). 


Fig.  74. — The  Cephalic  Aspect  of  the 
Left  Arm,  with  the  Ectal  Mus- 
cles OF  the  Scapula. 


Posture. — Similar  to  that  for  the  dissection  of  the  sub  scapular  is, 
excepting  that  the  arm  should  rest  upon  the  caudal  (inner)  side, 
and  the  mesoscapula  should  be  toward  the  observer. 

Dissection. — Note  that  the  ectal  surface  of  the  muscle  is  cov- 


M.     SPINO-DELTOIDEUS.  255 

ered  by  a  firm  fascia,  whicli  is  closely  attaclied  along  the  border  of 
the  mesoscapula  and  the  coracoid  border  of  the  scapula  excepting 
where  it  was  separated  from  the  sub  scapular  is.  Divide  these 
attachments,  cutting  from  the  glenoid  angle  of  the  scapula  toward 
the  vertebral  border,  then  transect  the  muscle  at  its  middle,  and 
reflect  both  parts  ;  the  proximal  part  may  be  wholly  removed. 

Origin. — By  fleshy  fibers  from  the  whole  supraspinous  fossa, 
and,  by  the  ectal  fascia,  from  the  coracoid  border  of  the  scapula 
and  mesoscapula. 

Insertion. — The  muscle  passes  over  the  capsule  of  the  shoulder 
joint  with  but  slight  adhesions  thereto,  and  ends  in  a  short,  thick 
tendon  which  is  attached  to  the  crest  of  the  trochiter.  Between  the 
trochiter  and  the  tip  of  the  acromion  process,  the  body  of  the  mus- 
cle is  closely  attached  to  the  border  of  the  acromio-deltoideus.  Tlie 
distal  cm.  of  the  other — the  coracoid — border  is  connected  with  the 
insertion  of  the  cephalic  division  of  the  entopectoralis^  as  described 
under  that  muscle  (g  658). 

M.    SPINO-DELTOIDEUS. 

§  674.  Synonymy.— The  spinal,  or  mesoscapular,  part  of  the  human  deltoideus,  G.,  A, 
404,  Q.,  A,  I,  199  ;  "  delto-spinni;'  S.-D.,  A,  II.  338  ;  part  of  •'  long  ahducteur  du  Iras,"  Ch., 
A,  263  ;  part  of  the  long  ahdactor  of  the  arm,  or  scapular  portion  of  the  deltoid,  Ch.  (Fl.), 
A,  249 ;  part  of  deltoid,  Miv.,  B,  147. 

Figures. — Ectal  aspect  (66,  67) ;  reflected  (74) ;  origin  area  (44)    insertion  area  (68). 

Posture. — Let  the  arm  rest  upon  its  caudal  surface  on  the  flat 
side  of  a  block,  with  the  elbow  toward  the  dissector.  The  scapula 
may  be  permitted,  at  times,  to  hang  over  the  end  of  the  block,  so 
as  to  render  the  muscle  tense. 

.  Exposure. — Remove  the  skin  upon  the  cephalic  surface  of  the 
brachium  to  the  junction  of  its  middle  and  distal  thirds.  Remove 
the  linn  fascia  covering  the  cephalic  side  of  the  shoulder. 

General  Description.— Thin,  apparently  subtriangular,  but 
really  trapezoidal ;  from  the  mesoscapula  and  metacromion  to  the 
deltoid  ridge  (Fig.  46,  68,  69),  on  the  proximal  half  of  the  cephalic 
surface  of  the  humerus. 

Dissection. — The  dorsal  border  forms  a  nearly  direct  line  be- 
tween the  tuberosity  of  the  mesoscapula  and  the  humerus  at  the 
junction  of  the  proximal  and  middle  thirds.  Lift  it  at  its  middle, 
where  it  crosses  the  angle  formed  between  the  muscles  upon  the 


256  ANATOMICAL     TECHNOLOGY. 

glenoid  border  of  the  scapula  and  the  dorsal  border  of  the  bra- 
chlum.  Here  it  is  easily  separated  from  the  subjacent  muscles,  but 
nearer  both  ends  it  adheres  very  closely.  Dissect  the  muscle  up 
toward  the  tip  of  the  metacromion.  Lift  the  overlapping  border  of 
the  acTomio-delioideus,  which  lies  just  ventrad  of  it  near  the  hu- 
merus. At  the  side  of  the  metacromion  toward  the  tip  of  the  acro- 
mion will  be  exposed  the  short,  free,  ventral  border  of  the  muscle. 
Connect  the  two  borders  and  reflect  the  ends.  In  reflecting  the 
scapular  part,  avoid  cutting  into  the  subjacent  infro.spinatus,  some 
fibers  of  which  take  their  origin  from  the  ental  surface  of  the  spino- 
deltoideus.  The  humeral  end  passes  entad  of  the  acromio-deltoi- 
deus^  most  of  the  fibers  of  which  are  inserted  upon  its  ectal  surface. 

§  675.  Origin. — By  short  tendinous  fibers  along  the  infraspinous 
border  of  the  mesoscapula  and  metacromion,  from  the  tuberosity 
of  the  former  to  the  glenoid  angle  of  the  latter,  and  from  a  tendinous 
raphe  between  this  muscle  and  the  acromio-trapezius. 

Insertion. — By  a  tendon  1-1.5  cm.  long  upon  the  deltoid  ridge 
of  the  humerus  ;  this  extends  obliquely  distad  along  the  proximal 
half  of  the  shaft  from  the  middle  of  the  cephalic  surface  to  the  ven- 
tral border.  The  ectal  surface  of  the  tendon  is  wholly  covered  by 
the  acromio-trapezius^  and  the  line  of  insertion  is  nearly  parallel 
with  that  of  the  insertion  of  the  ectal  lamina  of  the  ectopectoralis. 

M.    ACROMIO-DELTOIDEUS. 

§  676.  Synonymy. —The  acromialy  or  intermediate,  part  of  the  human  deltoideufi,  G., 
A,  404,  Q. ,  A,  1, 199  ;  "  delto-acromial,"  S.-D.,  A,  II,  338 ;  part  of  the  "  long  abducteur  du 
bras"  Ch.,  A,  363 ;  part  of  the  long  abductor  of  the  arm,  or  scapular  portion  of  the  deltoid, 
Ch.  (Fl.),  A,  249 ;  part  of  deltoid.  Mi  v.,  B,  147. 

Figures,  Posture  and  Exposure. — As  with  the  M.  spino-del- 
toideus. 

General  Description. — A  short  band,  from  the  acromion  to  the 
deltoid  ridge  of  the  humerus. 

Dissection. — The  dorsal — and  longer— border  was  lifted  in  order 
to  expose  the  tendon  of  the  spino-deltoideus.  The  shorter— or  ven- 
tral—border may  be  traced  from  the  tip  of  the  acromion  to  a  point 
near  the  proximal  end  of  the  line  of  insertion  of  the  same  muscle, 
and  forms  the  dorsal  limit  of  the  subcutaneous  area  of  the  trochiter 
(marked  ce  in  Fig.  74). 

§  677.   Origin.— By  short  tendinous  fibers  along  the  infraspinous 


3L    INFRASPINATUS,  257 

border  of  the  acromiori^  and  the  contiguous  border  of  the  metad^o- 
Tnion  to  near  the  tip  of  the  latter. 

Insertion. — Most  of  the  hbers  seem  to  terminate  upon  the  ectal 
surface  of  the  tendon  of  the  spino-deltoideus^  but  the  ectal  layers, 
esijecially  at  the  borders  of  the  muscle,  are  connected  with  the  bone 
by  a  thin,  tendinous  sheet,  which  is  attached  along  a  sliorter  and 
straighter  line  than  that  of  the  insertion  of  the  muscle  just  named 
and  between  it  and  the  insertion  of  the  ectal  layer  of  the  ectopecto- 
rails.  The  proximal  end  of  the  line  of  insertion  is  3-4  mm.  ventrad 
and  distad  of  the  proximal  end  of  the  line  of  insertion  of  the  splno- 
deltoideus, 

M.   INFRASPmATUS. 

§  678.  Synonymy. — The  human  infraspinatus,  G.,  A,  405,  Q.,  A,  I,  200;  "  sous-epi- 
neux,"  S.-D.,  A,  II,  344  ;  "  sous-epineua;,"  Ch.,  A,  265  ;  supraspinatus,  Ch.  (Fl.),  A,  251 ; 
infraspinatus.  Mi  v.,  B,  148. 

Figures. — Ectal  aspect  (67,  74) ;  origin  area  (44) ;  insertion  area  (68). 

Posture. — As  for  the  M.  supraspinatus. 

Exposure. — By  the  reflection  of  the  MM.  spino-trapezius^  lega- 
tor clamculcB^  spino-deltoideus  and  acromio-deltoideus. 

General  Description. — From  the  infraspinous  fossa  to  the 
Fossa  trocJiiteriana  of  the  humerus  (Fig.  45,  B). 

Dissection. — The  rounded  mesoscapular  border  may  be  seen 
between  the  head  of  the  humerus  and  the  metacromion,  where  it  is 
overarched  by  the  acromion.  The  border  is,  for  the  most  part,  in 
close  contact  with  the  small  micostalis^  but  close  to  the  humerus 
1  is  an  interval  filled  by  connective  tissue.  Follow  this  interval 
nearly  to  a  point  opposite  the  metacromion,  and  then  divide  the 
infraspinatus. 

In  reflecting  the  humeral  part,  note  a  synovial  bursa  between 
the  tendon  and  the  dorsal  slope  of  the  fossa  of  insertion.  The  scap- 
ular half  separates  readily  from  the  micostalis  (marked  teres  minor 
u]^on  the  figures),  but  from  the  teres,  nearer  the  vertebral  end  of  the 
scapula,  it  can  be  separated  only  by  cutting  fibers. 

Origin. — By  fleshy  fibers  from  the  entire  supraspinous  fossa,  and 
by  short,  tendinous  fibers  from  the  raphe  between  it  and  the  teres. 

Insertion.~By  a  strong  tendon  into  the  ventral  half  of  a  depression 
{Fs.  trocTiiteriana,  %  404)  upon  the  cephalic  aspect  of  the  trochiter. 
The  proximal  end  of  the  insertion  is  almost  in  contact  with  the  attach- 
ment of  the  supraspinatus  upon  the  crest  of  the  trochiter.  The 
17 


258  ANATOMICAL    TECHNOLOGY. 

insertion  of  the  cephalic  division  of  the  ental  lamina  of  the  ento- 
pectoralis  extends  just  dorsad  from  this  depression,  and  the  Tuber- 
culum  micostale  is  just  distad  of  it. 

M.   MICOSTALIS. 

g  679.  Synonymy.— The  Imman  teres  minor,  G.,  A,  406,  Q.,  A,  I,  201  ;  "  micostal ,'' 
S.-D.,  A,  11,  345  ;  "  court  abducteur  du  bras,  ou  petit  rond,"  Cli.,  A,  265  ;  short  abductor  of 
the  arm,  or  teres  minor,  Ch.  (Fl.),  A,  350  ;  teres  minor,  Miv.,  B,  148. 

Figures. — Ectal  aspect  (74,  where  the  muscle  has  its  more  common  name  teres  minor); 
origin  area  (43) ;  insertion  area  (68). 

Posture.— As  for  the  M.  infraspinatus  (§  678). 

Exposure. — By  the  reflection  of  the  M.  infrasioinatus. 

General  Description. — Small,  from  part  of  the  glenoid  border 
of  the  scapula  to  the  Tuherculum  micostale  (Fig.  ^^. 

Dissection. — The  mesoscapular  border  was  exposed  by  the  re- 
moval of  the  infraspinatus.  The  opposite  border  is  nearly  in  line 
with  the  glenoid  border  of  the  scapula,  and  it  is  only  necessary  to 
remove  some  ccmnective  tissue  between  it  and  the  oblique  border  of 
the  ectotriceps^  and  to  dissect  up  the  muscle  from  the  meditriceps, 
to  which  it  adheres  somewhat  closely.  In  reflecting,  note  the  close 
attachment  of  the  ental  surface  to  the  capsule  of  the  shoulder  joint. 

Origin. — By  a  sheet  of  tendinous  fibers  from  the  glenoid  border 
of  the  scapula,  beginning  about  one  fifth  of  the  length  of  the  border 
from  the  glenoid  fossa,  and  ending  at  its  middle. 

Insertion. — By  a  very  short  tendon  upon  the  Tbcl,  micostale  on 
the  cephalic  aspect  of  the  trochiter. 

M.   TERES. 

§  680.  Synonymy.— The  human  teres  major,  G.,  A,  406,  Q.,  A,  I,  202  ;  "  teres,"  S.-D., 
A,  II,  809  ;  '*  ahducteur  du  bras,  ou  grand  rond,''  Ch.,  A,  267  ;  abductor  of  the  arm,  or  teres 
major,  Ch.  (Fl.),  A,  253;  teres  major,  Miv.,  B,  148. 

Figures. — Ectal  aspect  (66,  67,  74);  ental  aspect  (75)  ;  origin  area  (43);  insertion  area 
(69,  70). 

Posture. — The  same  as  for  the  M.  sub  scapular  is. 

Exposure.  —If  the  bicipital  arch  has  not  been  divided,  it  must 
be  now ;  the  brachial  artery  and  nen^es  accompanying  it  must  be 
removed,  and  the  body  of  the  M.  bicejys  pushed  ventrad. 

General  Description. — A  thick  band  ;  from  the  glenoid  border 
of  the  scapula  to  the  ventral  surface  of  the  humerus^  a  little  distad 


M.    EPITROCHLEARIS,  259 

of  its  head  ;  associated  at  its  origin  with  the  subscapular is^  and  at 
its  insertion  with  the  latlssimus. 

Dissection.— Both  borders  of  the  muscle  have  been  indicated 
during  the  examination  of  the  subscapularis  and  latissimus.  Con- 
nect them  at  tlie  point  of  junction  of  the  M.  teres  with  the  last  named 
muscle.  The  scapular  part  of  the  muscle  may  be  dissected  from  its 
attachment  along  the  border  of  the  scapula,  but  the  humeral  part- 
together  with  the  humeral  part  of  the  latissimus — can  be  reflected 
with  ease. 

Origin. — By  flesliy  fibers,  from  all  but  the  glenoid  sixth  of  a 
shallow  groove  along  the  glenoid  border  of  the  scapula  ;  this  groove 
intervenes  between  the  true  glenoid  border  and  the  marked  ridge 
upon  the  subscapular  surface  which  runs  nearly  parallel  with  it  at 
a  distance  of  4-5  mm.  It  arises  also  from  the  aponeurotic  septum 
between  it  and  tlie  subscapular  is. 

Insertion. — This  has  been  described  in  connection  with  the 
M,  latissimus  (§  635). 

M.   EPITROCHLEARIS. 

§  681.  Synonymy. — The  dorso-epitrocJdien  of  monkeys,  and,  by  exception,  of  man,  Q., 
A,  I,  207  ;  "  triceps-interne,"  S.-D.,  A,  II,  348;  dorso-epitrochlear,  Miv.,  A,  137. 

Figures. — Ectal  aspect  (72,  left  side) ;  distal  end,  reflected  (72,  right  side)  ;  both 
ends  (75). 

Posture. — Let  the  arm  rest  upon  its  cephalic  surface,  with  the 
olecranon  and  the  gleno- vertebral  angle  of  the  scapula  toward  the 
dissector.  The  muscle  was  exposed  during  the  dissection  of  the 
pecto-antebrachialis  and  clavo-deltoideus. 

General  Description. — A  thin  ribbon,  from  the  vertebral  bor- 
der of  the  latissimus  to  the  caudal  border  of  the  olecranon  process 
of  the  ulna. 

Dissection.— The  ventral  border  was  indicated  in  the  dissection 
of  the  pecto-antebrachialis  ;  the  dorsal  border  may  be  seen  if  the 
latissimus  is  drawn  toward  the  head  of  the  humerus.  Both  borders 
should  be  freed  from  connective  tissue  and  thin  fascia ;  then  the 
muscle  may  be  divided  at  its  middle. 

Origin. — Variable  and  ill  defined.  By  fleshy  fibers  from  the 
ventral  border  of  the  latissimus,  just  opposite  the  oblique  line  of 
union  of  the  latter  muscle  with  the  teres^  and  close  to  the  place  of 
reception  of  the  dermo-humeralis  ;  occasionally  some  of  the  fibers 
arise  from  the  latter  muscle. 


%60  ANAT03IICAL    TECHNOLOGY. 

Insertion. — At  the  epiirochlea  the  fleshy  fibers  are  replaced  by 
a  thin  tendon  which  really  forms  part  of  the  general  antebrachial 
fasciay  and  is  continuous  with  the  tendons  of  the  pecto-antebrachi- 
alis  ;  so  much  of  the  fascia  as  belongs  to  this  muscle  is  attached 
along  the  proximal  10-15  mm.  of  the  caudal  border  of  the  triangular 
subcutaneous  area  upon  the  dorsal  aspect  of  the  olecranon. 

M.   MEDITRICEPS. 

§  682.  Synonymy. — The  human  middle  or  scapular  head  of  the  triceps,  G.,  A,  400,  Q., 
A,  I,  207  ;  "  hiceps-moyen"  S.-D.,  A,  II,  348 ;  "  long  extenseur  et  gros  extenseur  de  Vavant 
Iras''  Cli.,  A,  273  ;  the  long  and  large  extensor  of  the  forearm,  Ch.  (Fl.),  A,  258;  second 
part  of  the  triceps,  Miv.,  B,  149. 

Figures. — Cephalic  aspect  (66,  67,  74)  ;  caudal  aspect  (72,  75)  ;  ori^n  area  (43). 

Posture. — At  first  the  arm  should  rest  upon  its  cephalic  side, 
but  the  posture  must  be  changed  several  times  during  the  dissection. 

Exposure. — By  the  reflection  of  the  MM.  latissiTnus^  teres  and 
epitrochlearis. 

General  Description. — Prismatic,  from  the  glenoid  third  of  the 
glenoid  border  of  the  scapula  to  the  olecranon. 

Dissection. — At  the  middle  of  its  length  the  ventral  border  of 
the  muscle  is  indicated  by  the  large  neri^e  which  lies  between  it  and 
the  M.  entotriceps.  Let  the  scapula  be  flexed  upon  the  brachium 
so  as  to  relax  the  muscle,  and  dissect  from  the  caudal  toward  the 
cephalic  border  along  its  entire  length,  as  far  as  the  epi trochlea. 

The  cephalic  surface  is  readily  separable  from  the  ectotriceps  ia 
its  proximal  fourth  ;  but  for  the  rest  of  its  length  it  is  united  with 
the  dorsal  border  of  that  muscle  by  a  strong  fascia.  In  reflecting 
the  distal  part,  note  the  close  union  of  both  borders  of  the  muscle 
in  its  distal  5  mm.,  and  the  presence  of  a  synovial  sacJc  over  the 
bifid  tip  of  the  olecranon. 

Origin. — By  a  short  tendon,  the  outline  of  the  section  of  which 
is  wedge-shaped,  the  base  toward  the  glenoid  end  of  the  scapula 
and  the  apex  toward  the  gleno-vertebral  angle.  The  line  of  origin 
occupies  nearly  the  glenoid  third  of  the  glenoid  border,  beginning 
about  1  mm.  from  the  glenoid  fossa. 

Insertion. — By  a  short  tendon  upon  the  rounded  tuberosity 
which  forms  the  dorsal  angle  of  the  olecranon  ;  the  ventral  border 
of  the  tubercle  is  indicated  by  a  slight  transverse  furrow. 

§  683.   Explanation  of  Fig.  75. — The  muscles  on  the  caudal 


MUSCLES    OF   THE    ARM.  261 

aspect  of  the  brachium  and  antebrachium,  and  the  ental  aspect  of 
the  scapula. 

Preparation. — The  cephalic  (outer)  aspect  of  the  same  arm  is 
shown  in  Fig.  75.  The  caudal  aspect  of  the  scapular  region  is  also 
represented  in  Fig.  73,  but  the  position  of  the  whole  limb  is  there 
reversed.  The  serratus  magnus  and  levator  anguli  scapulce  have 
been  transected  a  little  nearer  the  scapula  than  the  rhoinboldeMS^ 
which  appears  ectad  of  them.  The  hicipital  arch  has  been  divided, 
and  the  biceps  and  epitrocMearis  transected  and  reflected  so  as  to 
expose  the  coracoideus  and  entotriceps.  The  muscles  on  the  caudal 
and  ventral  aspect  of  the  antebrachium  have  been  merely  freed 
from  fat  and  fascia. 

Bones,  etc. — Antebraefdum — the  forearm  ;  hracMum — tlie  upper  arm  or  proximal 
segment  of  the  arm. 

Ftn,  {Foramen)  epitrochleare  (Fig.  46,  §  417). — A  part  of  its  ventral  orifice  is  covered  by 
the  humeral  end  of  the  M.  entotriceps,  dv.  hrems. 

Humerus  (Fig,  45,  46,  68-71,  §  407).— Most  of  the  caudal  aspect  of  this  bone  is  exposed  ; 
the  trochin  appears  at  the  proximal  end. 

Olecranon  (Fig.  30,  §  220). — The  prominence  of  the  elbow. 

Pre.  (Processus)  coracoideus — The  coracoid  process  of  the  scapula  (Fig.  43,  44,  45,  A, 
§  400). — In  the  shaded  space  between  the  supraspinatus  and  subscapularis  projects  the  tip 
of  this  process.  Connected  therewith  are  the  origin  tendon  of  the  coracoideiLS  and  the 
tendinous  slip  from  the  insertion  tendon  of  the  entopectoralis,  dv.  cephalica. 

Muscles. — The  following  have  been  sufficiently  described  elscAvhere,  and  in  the  expla- 
nations of  the  figures  whose  numbers  are  placed  in  parentheses:  — 

Latissirn.u8  (67),  §  635  ;  subscapularis  (73),  §  670  ;  supraspinatus  (67,  73),  §  675 :  supina- 
tor longus  (74),  §  690. 

Biceps  (§  694). — The  distal  end  is  seen  to  pass  to  the  ulna  between  the  proximal  ends 
of  the  two  groups  of  muscles  lying  on  the  ventral  aspect  of  the  antebrachi  am :  the  flexores, 
including  the  pronator  teres,  and  the  extensores,  including  the  supinator  longus  (see  ^5  695). 
The  tendon  of  origin  passes  entad  of  and  through  the  Canalis  hicipitalis  to  the  Tbcl.  bicipi- 
tale  (Fig.  45,  A)  of  the  scapula,  but  in  this  figure  it  has  the  appearance  of  continuity  with 
the  slip  from  the  entopectoralis  to  the  Pre.  coracoideus. 

BracJiialis  (§  692). — Only  a  portion  is  seen  between  the  MM.  pronator  and  ectopectoralis. 

Coracoideus  (§  668). — The  caput  breve  has  been  shown  in  Fig.  73,  and  appears  here 
passing  eephalad  of  (behind)  the  insertion  tendon  of  the  MM.  teres  and  latissimus.  The 
caput  longum  is  seen  to  pass  caudad  of  the  same  tendon,  to  become  a  very  slender,  thread- 
like tendon,  and  to  become  attached  to  the  ventral  margin  of  the  Fm.  epitrochleare. 

Ectopectoralis,  Im.  entalis,  dc.  caudalis  (§  653).— The  remnant  of  muscle  so  named  evi- 
dently includes  also  part  of  the  caudal  division  of  the  entopectoralis. 

Entopectoralis  (§  658). — The  name  begins  near  the  insertion  tendon  of  the  cephalic 
division. 

Entotriceps,  dv.  brecis  (§  688).— This  is  not  only  the  shortest  division  of  the  entotriceps, 
but  forms  a  very  different  angle  with  both  the  humerus  and  the  olecranon. 

Entotriceps,  dc.  caudalis  (%  687)  ;  dv.  cephalica  (§  689) :  dv.  intermedia  (§  686). -The 
relative  positions  of  these  thrae  divisions  of  the  entotriceps  are  more  clearly  shown  upon 


262 


^iV^  TOMICAL    TECHNO  L  OGT. 


Fig.  71,  where  their  origin  areas  are  seen  to  be  respectively  intermediate,  distal  and  jyroxi- 
mal.  It  should  be  remembered  that  the  names  here  applied  to  them  are  merely  provisional. 
EpitrocJilearis  (§  681). — The  proximal  end  is  in  position  ;  the  distal  tendon  has  been 
reflected  ;  the  tendons  of  the  two  divisions  of  the  pecto -antebrachial is  (§§  645-647,  Fig.  73), 
with  which  it  is  associated,  have  been  removed. 

Extensor  (carpi)  radialis  hremor  (%  696) ; 
ex.  rad.  longior  (§  6C4).— The  former  of 
these  two  associated  muscles  was  but  par- 
tially visible  in  Fig.  74. 

Flexor  {digitorum)  communis  ectalis. — 
This  represents  the  common  flexor  of  the 
digits  which,  in  Anthropotomy,  is  called  snb- 
limis,  superficial!' s  or  perforatus.  It  is  not 
particularly  described  herein. 

Flexor  {carpi)  radialis  (§  702). — The  divi- 
sion of  the  insertion  tendon  described  by 
Straus-Durckheim  does  not  appear  in  this 
figure. 

Latissimus  (§  635). — After  the  division 
of  the  bicipital  arch,  the  parts  immediately 
concerned  in  its  formation  were  removed. 
The  figure  shows  the  intimate  association 
f  the  distal  ends  of  the  latimmus  and  teres, 
and  the  origin  of  the  epitrochlearis  from  the 
ectal  aspect  of  the  former  near  its  ventral 
margin. 

Lewtor  angull  scapuUp,  (§  666). — As  shown 
in  Fig.  43  and  73,  the  origins  of  this  and  of 
the  serratus  magnns  are  practically  contin- 
uous. 

Meditriceps  (§  682).— The  cephalic  aspect 
of  the  proximal  end  appears  in  Fig.  74. 

Bhomhoideus  (§  620). — The  scapular  end 
of  this  muscle  is  seen  to  be  coextensive  with 
the  scapular  ends  of  the  serratus  magnus 
and  lexiator  angull  scapuloe,  but,  as  shown 
upon  Fig.  43  and  44,  the  insertion  area  is 
partly  upon  the  ental  and  partly  upon  the 
ectal  aspect  of  the  vertebral  margin  of  the 
bone. 

Serratus  magnvs  (§  664).— See  let),  ang. 
scap.,  above. 

Teres  (§  680). — As  stated  elsewhere,  the 
word  major  is  superfluous.  The  figure  well 
shov.'s  the  passage  of  the  combined  tendons 
of  this  muscle  and  the  latissimus  between  the  two  heads  of  the  coracoideus. 


Fig.  75.— The  MuscliEs  upon  the  Ental 
Aspect  of  the  Scapula  and  the 
Caudal  Aspect  of    the    Brachium 

AND  AnTEBRACHIUM. 


M.    ENTOTEICEPS.  263 

M.    ECTOTRICEPS. 

§  684.  Synonymy. — The  external  head  of  the  human  triceps,  G.,  A,  409,  Q.,  A,  1, 207  ; 
''triceps  externe,"  S.-D.,  A  II,  347  ;  "  coui't  extzriseur  de  I'avant  bras,"  Ch.,  A,  273  ;  short 
extensor  of  the  forearm,  Ch.  (Fl.),  A,  259  ;  first  division  of  the  triceps,  Miv.,  B,  149. 

Figures. — Ectal  aspe;it  (66,  67,  74) ;  origin  area  (71). 

Posture. — The  arm  may  rest  upon  the  shoulder  and  wrist,  the 
elhow  looking  upward,  the  dorsal  aspect  of  the  brachium  toward 
the  dissector,  and  the  antebrachium  leaning  against  a  block. 

Exposure. — The  muscle  is  subcutaneous  in  its  whole  length,  and 
was  exposed  in  removing  the  skin  from  the  cephalic  aspect  of  the 
brachium. 

General  Description. — A  flattened  fusiform  mass,  from  the 
proximal  part  of  the  deltoid  ridge  of  the  humerus  to  the  cepTialic 
aspect  of  the  olecranon. 

Dissection. — The  dorsal  border  was  cut  from  the  cephalic  border 
of  the  meditriceps^  and  the  whole  muscle  is  attached  to  the  subja- 
cent muscles  only  by  connective  tissue ;  an  artery  enters  its  ental 
surface  a  little  pro xi  mad  of  the  middle  of  the  length,  and  must  be 
divided.  The  ventral  border  is  attached  to  the  hracMalis  upon  the 
cephalic  side  of  the  arm  by  a  strong  fascia,  but  at  the  middle  of  the 
muscle  it  is  thinner  than  elsewhere,  and  may  be  cut  first.  Then 
transect  the  muscle  and  reflect  it,  dividing  the  fascia  between  its 
ventral  border  and  the  adjacent  parts. 

Origin. — By  a  thin  tendon  from  the  proximal  part  of  the  deltoid 
ridge  and  from  the  dorso-cephalic  aspect  of  the  neck  of  the  humerus. 
The  line  of  attachment  is  curved  so  as  to  pass  ventrad  of  the  tuber- 
cle for  the  insertion  of  the  micostalis^  and  dorsad  of  the  origin  of 
the  middle  division  of  the  entotriceps,  some  fibers  of  which  seem  to 
spring  from  the  tendon  of  the  ectotriceps.  The  line  begins  about 
5  mm.  proximad  of  the  proximal  end  of  the  line  of  insertion  of  the 
spino-deltoldeus. 

Insertion. — The  proper  tendon  is  5  mm.  wide  at  its  attachment 
to  the  cephalic  border  of  the  olecranon,  but  the  distal  half  of  the 
ventral  border  of  tlie  muscle  is  so  firmly  connected  to  the  brachial 
and  antebrachial  fascia  that  it  may  be  said  to  have  a  general  inser- 
tion upon  the  region  about  the  elbow. 

M.    ENTOTRICEPS. 

§  685.    Remark. — The  remaining  extensors  of  the  antebrachium  are  not  easy  to 
pmologize  with  the  parts  of  the  human  triceps,  anconeus  and  subanconeus ;  the  names 


264  ANATOMICAL   TECHNOLOGY. 

here  given  to  tliem  are  provisional  and  descriptive  rather  than  designatory.     They  readily 
separate,  and  no  special  directions  for  dissection  are  required. 

DV.    INTERMEDIA. 

§  686^.    Synonymy.— Straus-Durckheim  (A,  II,  350j  calls  this  "  le  premier  chef  de 
Vancone  moyen  " ;  Mivart  describes  it  as  the  fourth  division  of  the  triceps  (B,  149). 
Figures.  —In  part  (75)  ;  origin  area  (68,  71). 

Origin. — By  fleshy  fibers  from  the  dorsal  surface  of  the  snrgical 
neck  of  the  humerus,  and  from  the  proximal  part  of  the  shaft. 
Sometimes  the  attachment  extends  upon  the  arthral  capsule.  The 
length  of  the  area  of  origin  equals  about  one  sixth  of  the  length  of 
the  humerus.  Its  caudal  border  is  encroached  upon  by  the  area 
of  insertion  of  the  M.  eoracoideus,  caput  hrexe,  but  the  cephalic 
border  is  rounded,  and  embraced  by  the  line  of  origin  of  the  M. 
ecfotriceps.  The  triangular  apex  of  the  area  lies  between  the  ori- 
gins of  the  caudal  division  next  to  be  described  and  the  M.  dracM- 
alis.  The  ventral  border  is  indicated  by  the  brachial  artery  and 
median  iierve  which  lie  between  it  and  the  dv.  caudalis. 

Insertion.  — At  the  junction  of  the  middle  and  distal  thirds  of 
the  humerus  the  muscle  ends  in  a  slender,  flat  tendon  which  widens 
slightly  as  it  nears  the  elbow,  rests  in  the  furrow  at  the  proximal 
end  of  the  bone,  and  is  inserted  into  the  oblique  ridge  which  forms 
the  dorsal  limit  of  the  furrow,  thus  slightly  ventrad  of  the  ridge  of 
insertion  of  the  medltriceps.  Between  the  tendon  and  the  floor  of 
the  furrow  is  a  synovial  capsule. 

DV.    CAUDALIS. 

§  687.  Synonymy.— Called  by  S.-D.  (A,  II,  350)  "  le  second  chef  de  Vancone  moyen  "  ; 
it  is  the  third  division  of  Mivart  (B,  149). 

Figures.— Caudal  aspect  (75)  ;  origin  area  (70,  71). 

Origin. — By  fleshy  fibers  from  a  subtriangular  area,  a  little 
proximad  of  the  middle  of  the  dorso-caudal  aspect  of  the  humerus. 
The  length  of  the  area  equals  about  one  sixth  of  the  length  of  the 
bone.  Its  apex  points  proximad,  and  is  almost  continuous  with 
the  apex  of  the  origin  area  of  the  Di^.  intermedia. 

Along  the  caudal  border  of  the  distal  part  of  the  muscle  runs 
the  ulnar  nerve  ;  the  A.  hracMalis  and  i\^.  medius  cross  the  dorsal 
border  at  about  the  junction  of  the  proximal  and  middle  thirds. 

Insertion. — By  short,  tendinous  fibers  upon  the  caudal  border 
of  the  venti-al  aspect  of  the  olecranon  as  far  as  the  lip  of  the  greater 
sigmoid  notch  (Fig.  30). 


M,    SUPINATOR    LONG  US.  265 


DV.   BREVIS. 

§  688.  Synonymy.— The  ancone  interne  of  S.-D.,  A,  II,  351 ;  the  fifth  dimsion  of  the 
triceps,  Mivart,  B,  149. 

Figures. — Ental  aspect  (75) ;  origin  area  (70,  71). 

Origin. — By  fleshy  or  short  tendinous  fibers  from  the  ectal  sur- 
face of  the  osseous  bar  which  encloses  the  Foramen  epitrocMeare, 
as  far  as  the  origin  area  of  the  pronator  teres  upon  the  epitrochlea. 

Insertion. — By  fleshy  fibers  into  the  caudal  border  of  the  olecra- 
non, just  distad  of  the  furrow  for  the  insertion  of  the  meditriceps, 

DV.   CEPHALICA. 

§  689.    Synonymy.— The  ancone  externe,  S.-D.,  A,  II,  350  ;  the  anconeus,  Miv.,  B,  149. 
Figures. — Indistinctly  (75) ;  origin  area  (71). 

Exposure. — The  strong  fascia  upon  the  cephalic  surface  of  the 
elbow  must  be  removed. 

Origin. — By  fleshy  fibers  from  the  elongated  triangular  surface 
upon  the  distal  half  of  the  dorsal  surface  of  the  humeral  shaft. 
The  cephalic  limit  of  the  area  is  indicated  by  the  prominent  ridge 
which  extends  obliquely  distad  from  the  middle  of  the  dorsal  sur- 
face to  the  epicondyle.  The  caudal  border  extends  more  nearly  in 
the  line  of  the  axis  of  the  bone. 

Insertion. — By  fleshy  fibers  upon  the  cephalic  side  of  the  olecra- 
non, from  the  insertion  of  the  middle  division  to  a  point  opposite 
the  distal  lip  of  the  greater  sigmoid  notch^  which  is  just  distad  of 
the  epicondyle.     The  insertion  area  is  about  2  cm.  long. 

The  ental  surface  of  the  muscle  is  attached  to  the  capsule  of  the 
elbow  joint,  but  its  thickness  indicates  that  it  serves  some  other 
purpose  than  that  suggested  by  Straus-Durckheim,  namely,  to  keep 
the  capsule  tense. 

M.   SUPINATOR  LONGUS. 

§  690.  Synonymy.— The  human  supinator  longus,  G.,  A,  415,  Q.,  A,  I,  215 ;  ''long 
snpinateur,"  S.-D.,  A,  II,  356  ;  "  long  supinateur,"  Ch.,  A,  289 ;  long  supinator,  Ch.  (Fl.), 
A,  272  ;  supinator  longus,  Miv.,  A,  151. 

Figures. — Cephalic  aspect  (74)  ;  caudal  aspect  (75) ;  origin  line  (71). 

Posture.-t-The  arm  may  rest  upon  the  caudal  surface  most  of 
the  time,  but  must  be  held  in  various  positions  at  different  stages 
of  the  dissection. 

Exposure. — Divide  the  skin  and  the  ectal  fascia  from  the  epi- 
condyle to  the  wrist,  and  girdle  the  arm  between  the  Mfninentia 


266  ANAT03nCAL    TECHNOLOGY, 

Tiypothenaris  (Fig.  105)  and  the  base  of  the  pollex.  Tlie  girdling 
must  be  done  with  care,  so  as  not  to  divide  any  of  the  tendons  at 
the  wrist.  Reflect  the  skin  and  fascia  first  upon  the  caudal  (ulnar) 
side  of  the  antebrachium. 

General  Description. — A  slender  muscle  from  the  cephalic  side 
of  the  humerus  to  the  distal  end  of  tlie  radius. 

Dissection. — If  the  antebrachium  is  extended  slightly,  the  free 
ventral  border  of  the  muscle  will  appear.  The  dorsal  border  is 
attached  by  connective  tissue  to  the  subjacent  muscles,  excepting 
close  to  the  ventral  border  of  the  brachiuni,  where  a  large  nerve 
passes  between  it  and  the  next  muscle.  Trace  this  border  distad  to 
near  the  end  of  the  radius,  noting  that  the  connections  with  the  sub- 
jacent muscles  become  firmer  toward  the  wrist.  Divide  the  muscle, 
and  reflect  the  proximal  end  ;  this  sometimes  adheres  so  closely  to 
the  cephalic  surface  of  the  'braeJilalis  that,  for  5-7  mm.  from  the 
humerus,  it  cannot  be  separated  without  cutting  flbers. 

Origin. — By  a  very  thin  tendon,  from  the  middle  fifth  of  the  dor- 
sal border  of  the  humerus ;  a  third  of  the  origin  line  lies  between 
the  origin  areas  of  the  hraclilaUs  and  the  cephalic  division  of  tlie 
entotriceps ;  the  rest  of  the  line  is  a  direct  proximal  continuation 
of  the  apex  of  the  origin  area  of  the  last  named  muscle,  and  ceases 
at  the  distal  end  of  the  origin  area  of  the  caudal  division. 

Insertion. — By  fleshy  fibers  upon  the  distal  end  of  the  radius, 
just  proximad  of  the  grooves  for  the  tendons  of  the  3fM.  extensor es 
radiales  and  upon  the  adjacent  ligaments. 

M.  BICEPS. 

§  091  Synonymy — The  human  hzceps  brnrJdalis,  Q.,  A,  408,  or  biceps  flexor  cubiti,  Q., 
A,  I,  205 ;  "  biceps,"  S.-D.,  A,  II,  353  ;  "  lonp  flechisseur  de  Vacant  bran  on  biceps  brachial" 
Ch.,  A,  371  ;  long  flexor  of  the  forearm  or  brachial  biceps,  Ch.  (Fl.),  A,  255  ;  biceps,  Miv.,  B,  148. 

Figures. — Ventro-caudal  aspect  (72,  73)  :  cephalic  aspect  of  distal  end  (74)  ;  reflected 
(75) ;  origin  point,  tuberculum  bicipitale  (45,  A,  43)  ;  insertion  point,  tuberositas  bicipi- 
tolls  (30). 

Posture. — At  first  the  arm  should  rest  upon  the  cephalic  side. 
The  muscle  was  exposed  by  the  division  of  the  hielpital  arch  (§  662). 

General  Description. — A  long,  fusiform  muscle  extending  the 
whole  length  of  the  ventral  surface  of  the  brachium,  from  the- 
bicipital  tubercle  of  the  scapula  to  the  bicipital  tuberosity  of  the? 
radius. 

Dissection. — No  preliminary  dissection  is  needed  beyond  freeing j 
the  muscle  from  fascia  and  connective  tissue.    After  transection,  if 


M.    BBACIITALTS.  267 

the  scapula  is  strongly  flexed  upon  the  brachium,  the  tendon  of  ori- 
gin of  the  muscle  may  be  seen  to  play  in  the  bicipital  groove.  If 
now  the  capsule  is  opened,  the  tendon  will  be  seen  to  be  still  cov- 
ered by  a  special  sheath,  so  that  it  does  not  lie  free  within  the  cap- 
sule. If  it  be  desirable  to  expose  the  whole  tendon,  the  dissector 
must  divide  the  coracoid  attachment  of  the  entopectoralis  and  the 
expanded  tendon  of  the  xiplii-humeralis. 

The  distal  end  of  the  M,  Mceps  must  then  be  freed  from  general 
connective  tissue,  and  special  note  taken  of  a  rather  firm  tendinous 
band  which  connects  the  caudal  side  of  the  muscle  with  the  fascia 
covering  the  M,  pronator  teres.  The  insertion  cannot  be  seen  until 
some  of  the  antebrachial  muscles  are  removed,  but,  by  lifting  the 
border  of  the  muscle  which  arises  from  the  epicondyle,  it  is  possible 
to  trace  the  tendon  of  the  Mceps  toward  a  point  upon  the  radius 
distad  of  the  attachment  of  the  clam-deltoideus  and  hracJiialis. 

Origin. — By  a  strong,  rounded  tendon,  1.5  cm.  long,  from  the 
prominent  glenoid  lip  of  the  glenoid  fossa  of  the  scapula.  (In  man, 
a  second  tendon— that  of  the  ''  short"  or  ''  coracoid"  head — arises 
from  the  tip  of  the  Pre,  coracoldeus.) 

Insertion. — By  a  similar,  though  slightly  shorter,  tendon  upon 
the  hicipital  tuberosity  of  the  radius.  An  additional  slight  inser- 
tion is  by  the  tendinous  band  above  mentioned  upon  the  ventral 
surface  oi  i\\e  pronator  teres. 

M.    BRACHIALIS. 

§  693.  Synonymy.— The  human  hrnchialis  antious,  G.,  A,  409,  Q.,  A,  1,  306 ;  "&ra- 
cldal"  S.-D.,  A,  II,  354  ;  "  court  fleclmseur  de  Uavant  bras  ou  hrachial  anterieur,'"  Cb.,  A, 
373  ;  short  flexor  of  the  forearm,  Ch.  (Fl.),  A,  356  ;  hrachialls  anticus,  Mi  v.,  B,  148. 

Figures. — Ectal  aspect  (74) ;  ental  aspect  (75) ;  origin  area  (68,  71) ;  insertion  area, 
indistinctly  (30). 

Posture. — With  this  and  the  remaining  muscles  the  appropriate 
posture  will  readily  suggest  itself  to  the  dissector. 

Exposure. — By  the  reflection  of  the  MM.  biceps  and  supinator 
longus. 

General  Description. — From  an  irregular,  long,  v-shaped  line 
upon  the  cephalic  surface  of  the  shaft  of  the  humerus  to  the  ulna 
near  its  proximal  end. 

Dissection.— Flex  the  brachium  slightly  upon  the  antebrachium 
so  as  to  relax  the  muscle.  At  the  border  of  the  antebrachium  push 
it  slightly  cephalad,  and  note  that  here  it  is  attached  to  the  hume- 


268  ANATOMICAL    TECHNOLOGY. 

rus  only  by  loose  connective  tissue,  which  may  be  torn  with  the 
tracer. 

Note  here  the  median  nerve  and  hracMal  artery  after  their 
passage  through  the  Foramen  epitrocMeare,  Still  keeping  the 
brachium  flexed,  separate  the  cephalic  side  of  the  muscle  from  the 
series  of  antebrachial  muscles  arising  from  the  cephalic  side  of  the 
humerus.  The  muscle  may  be  divided  just  proximad  of  its  union 
with  the  clavo-deltoideus. 

%  693.  Origin. — By  fleshy  fibers  from  an  irregular,  long,  v- shaped 
line  extending  almost  the  whole  length  of  the  cephalic  surface  of  the 
shaft  of  the  humerus.  The  apex  of  the  v  is  represented  by  a  trian- 
gular area  a  little  distad  of  the  tubercle  for  insertion  of  the  M. 
micostalis. 

The  dorsal  and  longer  branch  of  the  v  extends  dorso-distad  to 
near  the  middle  of  the  length  of  the  bone,  thence  distad  to  the  crista 
epicondylaris^  which  it  follows  to  opposite  the  proximal  end  of  the 
jFm.  epitroclileare. 

The  ventral  branch  runs  ventro-distad  parallel  with  the  crista 
deltoidea,  then  distad  to  about  the  junction  of  tlie  middle  and  distal 
thirds  of  the  bone. 

Each  of  these  branches  is  2-4  mm.  wide,  and  is  really  therefore 
a  long  and  narrow  area  rather  than  a  line.  The  triangular  space 
between  them  does  not  give  origin  to  fibers. 

Insertion. — From  this  peculiar  origin  the  fibers  converge  to  form  a  flat  tendon  .5-1  cm. 
wide,  which  is  closely  attached  by  its  octal  surface  to  the  ental  surface  of  the  tendon  of 
the  M.  davo-deltoideus.  The  tendon  of  the  brachialis  is  inserted  upon  the  dorsal  portion  of 
the  depressed  rough  area  on  the  caudal  aspect  of  the  ulna  just  distad  of  the  greater  sig- 
moid notch  and  about  midway  between  the  dorsal  and  ventral  margins  of  the  bone. 

This  account  of  the  M.  brachialis  is  derived  mainly  from  the  illustrated  Thesis  of 
Homer  Collins,  B.  S.,  a  special  student  in  the  Anatomical  Laboratory  of  Cornell  Univer- 
eity.  The  dotted  lines  upon  Fig.  68,  71  approximately  include  the  outline  of  the  v-shaped 
line,  but  they  should  be  double, 

M.  EXTENSOR  (CARPI)  RADIALIS  LONGIOR. 

§  694  Synonymy. — The  human  muscle  of  the  same  name,  G.,  A,  415,  Q.,  A,  I,  216; 
"premier  radial,"  S.-D.,  A,  II,  359  ;  part  of  the  "  extenseur  anterieur  du  metacarpe"  Ch., 
A,  277  ;  part  of  the  anterior  extensor  of  the  metacarpus,  Ch.  (FL),  A,  262  ;  extensor  carpi 
radialis  longior,  Miv.,  B,  151. 

Figures. — Cephalic  aspect  (74) ;  caudal  aspect  (75) ;  origin  area  (71). 

General  Description. — From  the  epicondylar  ridge  of  the  humerus  to  the  proximal 
end  of  the  indical  metacarpal. 


M.    EXTENSOR    {CARPI)    RADIALIS    BREVIOR.  269 

Dissection. — Just  dorsad  of  the  insertion  of  tlie  supinator  longus  is  the  oblique  border 
of  the  strong  tendon  of  the  M.  extensor  ossis  metacarpi  polUcis.  Entad  of  this  tendon  may- 
be seen  another  tendon  evidently  continuous  with  the  muscle  lying  along  the  cephalic  bor- 
der of  the  autebracbium.  With  the  tracer,  separate  the  tendon  into  two,  an  ectal  and 
more  slender,  and  an  ental  and  thicker.  Tlie  former  may  be  traced  proximad  for  two 
fifths  of  the  length  of  the  antebrachium,  where  it  is  continiious  with  its  muscle,  the  extensor 
carpi  {radialis)  longlor. 

Divide  the  muscle  at  the  middle  ;  in  reflecting  the  proximal  end,  note  that  it  becomes 
thinner  and  wider,  is  wedged  somewhat  between  two  subjacent  muscles,  and,  at  the 
humerus,  has  a  third  or  a  fourth  overlapped  by  the  muscle  arising  just  distad  of  it. 

By  pulling  upon  the  tendon,  and  alternately  flexing  and  extending  the  manus,  it  may 
be  seen  that  the  tendon  passes  across  the  carpus  entad  of  the  oblique  tendon  of  the  exten- 
sor metacarpi  pollicis.  With  the  arthrotome,  cut  the  fascia  at  one  side  of  the  tendon  upon 
the  carpus,  introduce  the  tracer,  and  thus  indicate  where  more  incisions  may  be  made  so 
as  to  expose  the  whole  tendon  as  far  as  the  proximal  end  of  the  indical  metacarpal. 

Note  that,  in  its  passage  over  the  distal  end  of  the  radius,  the  tendon  lies  in  a  groove 
upon  the  dorso-cephalic  side  of  the  bone,  separated  by  a  triangular  elevation  from  the 
groove  for  the  tendon  of  the  extensor  metacarpi  pollicis. 

%  695.  Remark. — By  analogy  with  tbe  less  modified  leg,  the  muscles  of  the  arm  which 
lie  upon  the  dorsal  aspect  of  the  antebrachium  and  are  inserted  upon  the  carpus  should  be 
called  flexors,  and  those  upon  the  caudal  aspect  extensors.  These  and  other  considerations 
have  been  presented  by  the  senior  author  (1  and  4).  In  an  ideal  myological  nomen- 
clature, we  believe  the  muscles  should  be  named  as  above,  but  in  the  present  practical 
work  it  seems  best  to  retain  the  designations  commonly  accepted. 

Origin. — By  fleshy  fibers  from  the  epicondylar  ridge  of  the  humerus,  between  the 
origin  area  of  the  supinator  longus  and  a  point  opposite  the  distal  end  of  the  Foramen  epi- 
trochleare.  The  larger  part  of  the  origin  line  lies  between  the  slender  distal  prolongation 
of  the  origin  area  of  the  bracMalis  and  the  triangular  origin  area  of  the  cephalk  division  of 
the  entotriceps.  The  distal  fourth  or  fifth  is  just  ventrad  of  the  origin  line  of  the  extensor 
communis  (digitorum). 

Insertion. — By  a  long  tendon  upon  the  dorsal  border  of  the  proximal  end  of  the  indi- 
cal metacarpal. 

Remark. — Like  other  tendons  which  pass  over  the  wrist,  this  is  held  in  place  by  liga- 
mentous bands  representing  parts  of  the  annular  or  armillary  ligaments. 

M.  EXTENSOR  (CARPI)  RADIALIS  BREVIOR. 

§  696.  Synonymy. — The  human  muscle  of  the  same  name,  G.,  A,  416,  Q.,  A,  I,  216  ; 
"  second  radial,"  S.-D.,  A,  II,  359  ;  part  of  the  '*  extenseur  anterieur  dumetacarpe"  Ch.,  A, 
277  ;  part  of  the  anterior  extensor  of  the  metacarpus,  Ch.  (Fl.),  A,  262  ;  ext.  carpi  rad.  Ire- 
vior,  Miv.,  B,  151. 

Figures. — Cephalic  aspect,  in  part  (74) ;  caudal  aspect  (75) ;  origin  area  (68). 

General  Description. — From  the  epicondylar  ridge  of  the  humerus,  just  proximad  of 
the  epicondylus,  to  the  base  of  the  medial  metacarpal. 

Dissection. — The  thicker  tendon  mentioned  as  joined  with  that  of  the  ex.  rad.  longior 
belongs  to  the  present  muscle.  This  tendon  is  shorter  than  the  other,  and  the  body  pro- 
portionately longer,  as  well  as  thicker.  Divide  it  1  cm.  farther  distad  than  in  the  case  of 
the  ex.  rad.  longior,  and  reflect  both  ends. 

Origin. — By  fleshy  or  short,  tendinous  fibers  from  the  epicondylar  crest,  just  distad  of 


270  ANATOMICAL    TECHNOLOGY. 

the  origin  of  the  ex.  I'ad.  long  tor.     The  origin  area  cannot  be  seen  fully  until  after  the 
remov^al  of  the  ex.  com.munis. 

Insertion. — The  tendon  passes  through  the  same  groove  as  the  tendon  of  the  ex.  rad. 
longior,  and  is  inserted  upon  the  dorsal  side  of  the  proximal  end  of  the  medial  metacarpal. 

M.  EXTENSOR  (DIGITORUM)  COMMUNIS. 

§  697.  Synonymy. — The  muscle  has  the  same  name  in  human  anatomy,  G.,  A,  417, 
Q.,  A,  I,  216 ;  extensmr  commune  des  doigts,  S.-D.,  A,  II,  364  ;  extenseur  anterieur  des  pha- 
langes, Ch.,  A,  275  ;  anterior  extensor  of  the  phalanges.  Ch.  (Fl.),  A,  263  ;  ext.  dig.  commw- 
nis,  Mi  v.,  B,  151. 

Figures.— Ectal  aspect  (74);  origin  area  (68,  71). 

Dissection. — The  muscles  remaining  upon  the  cephalic  and  dorsal  surfaces  of  the  ante- 
bracliium  are  covered  by  a  dense  fascia  which  must  be  removed.  Near  the  wrist  note  a 
wide  tendon  which  passes  ectad  of  the  M.  abductor  ossis  metacarpi  poUicis.  Trace  it  to  the 
corresponding  muscle,  and  this  to  the  humerus,  and  transect  the  muscle  at  its  middle. 

Origin. — By  fleshy  and  tendinous  fibers  from  the  epicondylar  ridge.  The  origin  area 
is  about  9  mm.  long,  and  extends  from  the  disto-cephalic  angle  of  the  origin  area  of  the 
cephalic  division  of  the  entotriccps  to  the  trochlea  ;  it  lies  just  dorsad  of  the  origin  area  of 
the  extensor  rad.  hrevior  and  of  the  distal  fifth  of  the  ex.  rad.  longior. 

Insertion. — The  tendon  lies  in  a  groove  upon  the  dorsal  surface  of  the  distal  end  of  the 
radius,  from  which  it  may  be  disengaged  by  slitting  up  the  ligament  which  converts  the 
groove  into  a  canal.  It  then  divides  into  four  tendons  which  may  be  traced  to  the  dorsal 
aspect  of  the/owr  ordinary  digits. 

M.    EXTENSOR  MINIMI   (DIGITI). 

§  698.  Synonymy.— The  human  muscle  so  called  (G.,  A,  417,  Q.,  A,  I,  218),  sends  a 
tendon  to  only  the  minimus,  while  in  the  cat  and  dog  what  seems  to  be  the  same  muscle 
supplies  also  the  annularis  and  medius ;  (see  Huxley,  A,  418).  S.-D.,  however  (A,  II,  368, 
369),  regards  it  as  forming  three  separate  muscles,  one  for  each  digit,  excepting  the  pollex 
and  index,  which  he  terms  Ex.  2^rop.  du  verpus,  paramese  and  micros,  respectively.  Exten- 
seur laterale  des  phalanges,  Ch.,  A,  279  ;  lateral  extensor  of  the  phalanges,  Ch.  (Fl),  A,  264 ; 
extensor  minimi  digiti,  Miv.,  B,  151. 

Figures. — Dorsal  aspect  (74) ;  origin  area  (68,  71). 

Origin. — From  the  ventral  border  of  the  epicondyle  just  distad  of  the  origin  of  the 
extensor  communis.  The  proximal  part  of  the  origin  is  by  muscular  fibers,  and  the  distal 
by  a  short  tendon  At  2-3  mm.  from  the  origin  the  muscle  divides  into  a  slender  ectal 
portion  and  a  thicker  ental  part,  which  are  in  close  contact,  but  may  be  separated  Avithout 
cutting  fibers.  The  former  becomes  tendinous  at  the  junction  of  the  proximal  and  middle 
thirds  of  the  autebrachium,  and  the  latter  at  the  junction  of  the  distal  and  middle  thirds. 

Insertion. — The  tendons  join  the  corresponding  tendons  of  the  extensor  commu7iis. 

M.   EXTENSOR  (CARPI)    ULNARIS. 

§  699.  Synonymy. — The  human  muscle  of  the  same  name,  G.,  A,  417,  Q.,  A,  I,  218 ; 
cubital,  S.-D.,  A,  II,  360  ;  ex.  carpi  ulnaris,  Miv,.  B,  152. 

Figures.— Dorsal  aspect  (74) ;  origin  area  (68). 

Origin. — In  two  parts  :  (A)  by  a  short,  broad  tendon  from  the  distal  end  of  the  epicon- 
dyle next  to  the  origin  of  the  extensor  minimi  ;  (B)  by  a  smaller  and  rounded  tendon 
from  the  proximal  lip  of  the  sigmoid  notch  of  the  ulna. 


M.     INDICATOR,  271 

Insertion. — The  muscular  fibers  continue  to  within  1  cm.  of  the  wrist ;  the  tendon, 
about  4  mm.  wide,  passes  over  the  distal  end  of  the  ulna,  is  connected  with  ligaments,  and 
is  inserted  upon  the  tubercle  at  the  caudal  side  of  the  proximal  end  of  the  minimal  meta- 
carpal. 

M.  INDICATOR. 

§  700.  Synonymy. — The  extensor  indicis  or  indicator,  Q.,  A,  I,  220  ;  extensor  indicis, 
G.,  A,  418  ;  "indicator,"  Dunglison,  A,  676  ;  "  indicateur,"  S.-D.,  A,  IT,  867  ;  ext.  indicis 
and  ex.  secuudi  internodii  polllcis,  Miv.,  B,  152. 

Origin. — Bv  fleshy  fibers  along  the  cephalic  border  of  the  ulna,  from  the  lesser  sigmoid 
notch  to  the  junction  of  the  distal  and  middle  thirds  of  the  bone,  exclusive  of  the  olecranon. 
The  proximal  third  of  the  muscular  portion  resembles  the  ordinary  antebrachial  muscles, 
and  is  continuous  with  a  slender  tendon ;  the  remaining  fibers  form  a  thin,  loosely  con- 
nected series  of  bundles  extending  distad  at  an  angle  of  about  45  degrees  with  the  bone  to 
be  attached  to  the  tendon  almost  to  the  wrist. 

Insertion. — At  the  wrist  the  tendon  divides  into  two,  both  of  which  are  connected  with 
the  indical  tendon  of  the  extensor  communis.  The  more  caudal  of  the  two  tendons  some- 
times receives  a  small  tendinous  slip  from  the  medial  tendon  of  the  extensor  minimi.  In 
some  cases  the  tendon  divides  into  three,  which  are  distributed  respectively  to  the  medius, 
the  index  and  the  second  segment  of  the  poUex. 

M.  PRONATOR  TERES. 

§  701.  Synonymy. — The  human  pronator  radii  teres,  G.,  A,  411,  Q.,  A,  1,209 ;  "rond 
pronateur,'"  S.-D.,  A,  II,  357  ;  pronator  teres,  Miv.,  B,  149. 

Figures. — Caudal  aspect  (75) ;  origin  area  (70,  71). 

Origin. — By  a  short,  strong  tendon  from  the  extremity  of  the  epitrochlea  just  distad 
of  the  origin  of  the  short  division  of  the  entotriceps. 

Insertion. — By  fleshy  and  short  tendinous  fibers  for  about  1.5  cm.  along  the  cephalic 
border  of  the  radius  at  its  middle. 

M.  FLEXOR  (CARPI)  RADIALIS. 

§  702.  Synonymy. — The  human  flexor  carpi  radialis,  G.,  A,  411,  Q.,  A,  I,  210  ;  "  cer* 
cialis,"  S.-D.,  A,  II,  362  ;  flsxor  carpi  radialis,  Miv.,  B,  149. 

Figures. — Caudal  aspect  (75)  ;  origin  area  (70). 

Origin. — By  fleshy  and  short  tendinous  fibers  from  the  distal  aspect  of  the  epitrochlea. 

Insertion. — The  muscle  becomes  tendinous  about  2  cm.  from  the  wrist,  passes  deeply 
entad  of  the  surface,  and,  according  to  Straus-Durckheim,  divides  into  two  tendons  which 
are  attached  to  the  indical  and  medial  metacarpals. 

%  703.  Other  Muscles. — Tn  addition  to  the  muscles  described  in  the  foregoing  pages, 
the  figures  indicate  more  or  less  fully  the  position  and  connections  of  the  following  :  3IM. 
supra-cervico-cutaneus  and  cermco-nuricularis  (86)  ;  temporalis,  masseter,  digastricus  and 
splenius  (67) ;  sterno-hyoideus,  sterno-thyroideus,  rectus  and  ectdbliquus  {abdominis)  (72) ; 
inter costales,  rectus,  ectoUiquus,  splenius  and  sterno-hyoideus  (73) ;  flexor  ulnaris  and  flexor 
digitorum  communis  ectalis  (75). 

The  muscles  just  named,  together  with  all  others  of  the  cat,  are  more  or  less  fully 
described  by  Straus-Durckheim,  and  most  of  them  are  at  least  enumerated  by  Mivart. 


272  ANATOMICAL    TECHNOLOGY, 

%  704.  The  Obvious  Structure  of  Muscle. — A  muscle  is  readily 
seen  to  be  a  collection  of  more  or  less  elongated,  reddish,  fleshy 
bundles  attached  at  each  end  more  or  less  independently  or  by  a 
common  fibrous  structure,  the  tendon.  The  bundles  are  easily  sep- 
arable into  smaller  bundles  cdUed  fasciculi.  A  'perimysium  or 
sheath  of  connective  tissue  surrounds  each  muscle,  and  from  this 
partitions  extend  between  the  fasciculi,  furnishing  each  with  a  sep- 
arate sheath. 

§  705.  Microscopic  Structure. — Fibers.— YjdiQ\\  fasciculus  is 
composed  of  a  variable  number  of  cylindrical  fibers. 

Striation.—'V\\Q  fibers  appear  to  be  composed  of  alternate  light 
and  dark  segments.  A  muscle  which  has  been  hardened,  in  alcohol 
for  example,  also  presents  an  appearance  of  longitudinal  striation, 
and  if  it  be  teased  carefully,  it  may  be  divided  into  finer  threads 
GsdledfibriUcB ;  each  fibril  la  shows  the  same  alternating  light  and 
dark  bands  as  the  entire  fiber. 

Sarcolemma. — Surrounding  each  fiber  is  a  delicate  sheath  of 
elastic  tissue. 

Nuclei  or  Muscle  Corpuscles. — These  are  clear  oval  bodies  found 
in  the  fibers.  In  Mammalian  muscles  they  lie  on  the  surface  of  the 
sarcolemma,  but  in  Amphibia  they  are  distributed  throughout  the 
substance  of  the  fibers. 

Length. — The  average  length  of  a  fiber  is  nearly  3  cm.  They 
are  of  nearly  uniform  size  throughout,  but  sometimes  branched  as 
in  the  tongue. 

Connection  with  Tendons. — A.  When  continued  in  a  direct  line 
with  a  tendon,  the  fiber  merges  into  the  tendon  somewhat  abruptly, 
yet  it  can  be  distinguished  from  tendon  only  by  the  absence  of 
cross  striation  in  the  latter. 

B.  When  the  fibers  join  the  tendon  at  a  more  or  less  acute  angle, 
they  terminate  in  rounded  ends  which  are  received  into  correspond- 
ing depressions  in  the  tendinous  structures.    Quain,  A,  II,  115. 


CHAPTER   VII. 

THE    ABDOMINAL    VISCERA,    SALIVARY    GLANDS,    MOUTH,   NECK    AND 

THORAX. 

LIST  OF  INSTRUMENTS  AND  MATERIAL — STOMACH — LIVER — PANCREAS — SMALL  INTES- 
TINE— LARGE  INTESTINE— URINARY  ORGANS — SALIVARY  GLANDS — MOUTH — NECK — 
THORAX — TRACHEA — CESOPHAGUS — THYMUS — DIAPHRAGM. 

ABDOMINAL  YISCEEA. 

There  is  first  given  a  general  consideration  of  the  parts,  to  enable 
the  student  to  recognize  them.  This  is  followed  bj  a  more  detailed 
description. 

§  706.  It  is  advisable  to  employ  at  least  two  specimens  for  the 
abdomen,  one  for  the  viscera  and  the  other  for  the  blood  vessels. 
If  specimens  cannot  be  obtained  readily,  the  thoracic  and  abdomi- 
nal viscera  and  vessels  may  be  studied  upon  a  single  individual. 

Preparation. — Just  before  the  explanation  of  each  figure  there  is  given  the  method  of 
preparing  the  part  or  organ  for  that  particular  figure.  The  directions  for  demonstration 
to  be  tbllowed  by  the  student  are  given  in  the  text  proper. 

§  707.  Names  of  Parts  in  Order  of  Examination,— {!)  Perito- 
neum ;  (2)  Diaphragma,  diaphragm  ;  (3)  Hepar,  liver,  and  cholecys- 
tis  or  gall  bladder ;  (4)  Storaachus,  stomach ;  (5)  Splen,  spleen ; 
(6)  Omentum  majus,  great  omentum ;  (7)  Intestinum  tenue,  small 
intestine;  (8)  Urocystis,  urinary  bladder ;^  (9)  Intestinum  amplum, 
large  intestine ;  (10)  Pancreas ;  (11)  Mesenterium,  mesentery ;  (12) 
Hen,  kidney  ;  (13)  Uterus  (or  vas  deferens) ;  (14)  Ovarium,  ovary. 

Instruments  and  Material. — Coarse  comb  ;  15  per  cent,  glycerin  ;  injecting  appa- 
ratus and  material  (§  336) ;  scalpel  ;  scissors ;  sponge  ;  thread  ;  towel  ;  tray  ;  tracer ; 
water. 

§  708.   Choice  of  Specimen. — Choose  a  young  adult,  lean  cat. 
It  may  be  fasting,  but  preferably  the  stomach  should  contain  a 
moderate  amount  of  solid  food. 
18 


274 


ANATOMICAL    TECHNOLOGY. 


%  709.  Posture  and  Prepgiration.— Place  the  cat  dorsi^nnibent ; 
fasten  the  arms  and  legs  laterad  with  cords  tied  to  the  loops  on  the 
edges  of  the  tray  (Fig.  76).  Take  the  precautions  for  cleanliness 
(§  199).  When  the  examination  is  made  in  warm  weather  or  is  to 
extend  over  several  days,  the  arteries  should  be  injected  with  alco- 
hol as  directed  in  §  284.    If  the  vascular  system  itself  is  to  be 


Fig.  76. — Lines  of  Incision  fob  Exposing  the  Thoracic  and  Abdominal 

Viscera  ;   x  .25. 

studied  in  the  same  individual,  both  arteries  and  veins  should  be 
injected  with  plaster  (§§  352,  362). 

If  the  thorax  is  not  to  be  studied,  open  it  (§  825),  cut  the  praecava  to  allow  the  blood  to 
escape,  and  inject  caud ad  through  the  postcava  and  the  aorta  thoracica.  If  the  vessels  are 
to  be  siucJisd  on  a  separate  specimen,  the  injection  may  be  omitted. 

Keep  all  exposed  parts  moist  with  the  15  per  cent,  glycerin  (§  171), 


ABDOMIXAL     VISCERA.  273 

§  710.  Exposure. — Determine  the  three  following  landmarks  by 
pressing  on  the  various  parts  of  the  abdomen  where  they  are  indi- 
cated (Fig.  76) :  (A)  The  ventrimeson  by  finding  the  xiphisternum 
(Fig.  30,  72,  §  228) ;  (B)  the  caudal  margin  of  the  12th  rib  (Fig.  30, 
72) ;  (C)  the  pubis  (Fig.  51,  76,  §  228). 

After  having  determined  the  three  landmarks,  the  hair  should 
be  moistened  and  parted  as  directed  above  (§§  354,  599) ;  then  the 
incisions  should  be  made  along  the  lines  indicated  in  Fig.  76. 
Make  the  incisions  in  the  manner  described  for  abdominal  transec- 
tion (§  237).  Reflect  the  four  flaps,  being  careful  not  to  tear  any  of 
the  thin  membranes — urocystic  and  hepatic  ligaments,  etc. — attached 
along  the  meson. 

Preparation  and  Exposure  —Fig.  77. — The  cat  was  fed  a  mod- 
erate amount  of  meat  about  an  hour  before  it  was  killed  with 
chloroform.  After  death  it  was  placed  dorsicumbent  on  the  dem- 
onstration board,  the  head  fastened  with  the  pointed  holder  (see 
Fig.  77),    and  the  limbs  secured  laterad  with  the  straps. 

After  parting  the  hair  (§  354),  an  incision  w^as  made  from  the 
angle  of  the  mouth  on  the  right,  along  the  middle  of  the  side  of 
the  neck,  thorax  and  abdomen,  then  on  the  left  side  as  far  cepha- 
lad  as  the  angle  of  the  mandible.  The  mucous  membrane  and 
the  thick  muscles  on  the  side  of  the  face  and  neck  were  cut  at 
the  same  level  as  the  skin,  and  the  right  mandibular  ramus  dis- 
jointed with  the  arthrotome.  The  hyoid  bone  (Fig.  30,  §  224)  was 
cut,  and  the  left  coronoid  process  (Fig.  61)  broken  with  nippers; 
this  made  it  possible  to  turn  the  mandible  to  the  left  so  as  to  expose 
the  pharynx  and  the  floor  and  roof  of  the  mouth. 

The  ribs  and  soft  parts  of  the  abdominal  and  thoracic  wall  were 
then  cut  with  scalpel  and  nippers  at  the  same  level  as  the  incision 
in  the  skin.  The  mediastinal  septum  and  the  diaphragm  were  cut 
with  scissors  close  to  the  ventral  wall,  and  the  entire  ventral  wall 
of  the  body  was  removed. 

In  some  specimens  the  ovary  {ovarium)  and  Mdney  {ren)  will 
not  appear  without  displacement  of  the  intestines,  and  in  old  ani- 
mals the  thymus  may  be  absent  (Fig.  77,  Cp.  thym.).  The  following 
parts  will  be  exposed  (Fig.  77) : — 

Description  of  Fig.  77.— Cardla,  a^.— Heart.  Cholecystis,  az, 
— Gall  bladder.  Cornu  Uteri. — Left  horn  of  tha  uterus.  Costaa. — 
Ribs  (13).  The  cut  ends  are  shown  on  each  side  of  the  thorax. 
Cp,  thym.,  Corpus  thymicum,  az. — Thymus  body  or  gland.     Dia- 


Z76^ 


ANAT03nCAL    TECHNOLOGY, 


o%x  dctStenofi 

'karton. 


Fig.  77.— General  View  of  thb  Visceka  ;    x  .35. 

phragma,    a^.— Diaphragm,    *^  midriff."      Epglt.,    Epiglottis,  az.  | 
Hepar,  az. — Liver.     Pointed  Holder.     Intestinum  amplum,  az. — 
Large  intestine.      Intestinum    Tenue,   az. — Small  intestine.     Lg. 
lat.,  Ligamentum  laterale. — Lateral  ligament  of   tlie  urocystis. 


ABDOMINAL     VISCERA,  ^11 

Xiin^a,  a^.— Tongue.  Mndb.,  Mandibula. — Mandible,  lower  jaw, 
(Es.,  CEsophagus,  az. — Gullet.  Omentum  majus,  az, — Epiploon, 
great  omentum,  caul.  O.  hy.,  Os  hyoides. — Hyoid  bone.  Ost. 
dct.  Stenon.,  Ostium  ductus  Stenoniani, — Mouth  or  opening  of 
tlie  duct  of  Stenon,  duct  of  the  parotid  gland.  Ost.  dct.  Wharton. , 
Ostium  ductus  Whartoniani. — Mouth  or  opening  of  Wharton's 
duct,  duct  of  the  submaxillary  gland.  Ovarium. — Ovary.  Pill 
tactiles. — Tactile  hairs  (see  Fig.  105).  Pulmo. — Lung.  Ren. — 
Left  kidney.  Splen,  az, — The  si3leen.  Stomachus,  az. — The  stom- 
ach. Tnsl.,  Tonsilla. — Left  tonsU.  (The  tonsils  are  composed 
mostly  of  lymphoid  tissue  and  are  abundantly  supplied  with  blood 
vessels  and  nerves.  The  function  of  the  tonsils  is  not  well  under- 
stood ;  Quain,  A,  II,  835).  Trachea,  az. — Wind-pipe.  Urocystis, 
az. — Urinary  bladder.  Vibrissee. — Whiskers.  VI.  pit.,  Velum 
palati,  az. — This  is  the  veil-like  or  pendulous  part  of  the  soft  pal- 
ate ;  its  caudal  margin  is  free  (Fig.  88). 

§  711.  Peritoneum  (§  725). — This  is  the  smooth  shining  mem- 
brane lining  the  abdominal  cavity  and  covering  the  viscera.  It 
may  be  separated  from  the  muscular  parietes  over  a  small  area  by 
using  the  tracer. 

§  712.  Diaphragma,  az.  (Fig.  77,  §  734).— Grasp  the  free  edge 
of  the  cephalic  abdominal  flaps  (Fig.  76) ;  draw  them  upward,  and 
look  toward  the  cephalic  end  of  the  abdominal  cavity.  The  dia- 
pliragm  will  appear  as  a  transverse  muscular  curtain  separating  the 
abdomen  from  the  thorax. 

§  713.  Hepar  and  Cholecystis,  az. — Liver  and  gall  bladder 
(Fig.  77,  §§744,  745). — The  liver  is  a  deep  red,  multilobular  organ 
occupying  nearly  the  entire  cephalic  part  of  the  abdomen,  but  espe- 
cially the  dextral  part. 

The  cholecystis  is  a  reservoir  for  bile  ;  it  usually  appears  as  a 
greenish  sac  in  one  of  the  lobes.  If  it  does  not  appear,  grasp  the 
caudal  margin  of  the  liver  and  turn  it  slightly  toward  the  thorax. 
The  cholecyst  will  appear  as  a  pear-shaped,  greenish  sac  partly 
imbedded  in  the  substance  of  the  middle  lobe. 

§  714.  Stomachus,  az.  (Fig.  77,  79,  §  735). — This  is  a  somewhat 
pear-shaped  organ  extending  obliquely  across  the  cephalic  part  of  the 
abdominal  cavity.  Its  larger,  cardiac  or  oesophageal  end  (Fig.  79) 
is  next  the  diaphragm  and  mainly  in  the  left  half  of  the  cavity. 
The  small  or  pyloric  end  is  sharply  curved.     It  is  partly  covered  by 


278  ANATOMICAL     TECHNOLOGY. 

the  liver,  and  may  be  fully  exposed  by  turning  the  edge  of  that 
organ  cephalad. 

The  space  occupied  by  the  stomach  depends  largely  on  the 
amount  of  food  it  contains. 

§  715.  Splen,  a^.— Spleen  (Fig.  103,  §  737).— This  is  a  deep  red, 
usually  single  lobed  organ,  situated  on  the  sinistro-caudal  aspect 
of  the  stomach. 

§  716.  Omentum  majus,  epiploon,  az, — Great  omentum  (Fig.  77, 
§  727). — This  appears  as  a  kind  of  transparent  apron  extending 
caudad  from  the  stomach.    It  contains  many  strips  of  fat. 

§  717.  Intestinum  tenue,  az. — Small  intestine. — Very  carefully 
turn  the  omentum  over  toward  the  thorax.  The  greatly  coiled  cyl- 
indrical small  intestine  will  be  exposed  (Fig.  77,  §  738). 

§  718.  Urocystis,^^.— Urinary  bladder  (Fig.  77, 101,  §  757).— In 
the  caudal  part  of  the  abdomen  will  be  seen  a  median  sac,  usually 
more  or  less  filled  with  liquid.  This  is  the  urocystis,  the  receptacle 
of  the  urine. 

§  719.  Intestinum  amplum,  az. — Large  intestine  (Fig.  77,  §  742). 
— ^Turn  the  coil  of  small  intestine  toward  the  left  leg.  The  large 
intestine  will  be  seen  on  the  right  side  extending  first  cephalad  from 
a  blind  extremity,  the  caecum  (Fig.  80),  nearly  to  the  stomach,  then 
transversely  across  the  cavity  a  little  to  the  left  of  the  meson,  and 
finally  somewhat  obliquely  caudad. 

§  720.  Pancreas,a^.(Fig.81, 103,  §746).— Turn  the  large  intestine 
to  the  left ;  the  pancreas  will  appear  as  a  pinkish,  finely  lobulated 
and  elongated  body  within  the  great  omentum  near  its  dorsal 
attachment  to  the  stomach.  It  extends  from  the  spleen  dextrad  to 
the  pylorus,  and  then  for  5-10  cm.  along  the  small  intestine  (Fig.  83). 

§  721.  Mesenterium,  a^".- Mesentery  (Fig.  78,  g  726).— Grasp 
the  small  intestine  and  lift  it  up.  The  mesentery  is  the  translucent 
membrane  supporting  the  intestine  and  serving  to  attach  it  to  the 
body.     It  is  a  fold  of  peritoneum  (§  726). 

§  722.  Ren— Kidney  (Fig.  101,  §  761).— Turn  the  stomach  and 
intestines  to  the  right,  and  the  left  kidney,  a  dark  red  body,  will 
appear  resting  on  the  ventral  surface  of  the  muscles  of  the  back 
near  the  meson  and  but  a  short  distance  from  the  diaphragm. 

§  723.  Uterus,  az.  (Fig.  77,  §  759).— Turn  the  urocystis  ventro- 
caudad,  and  if  the  animal  is  a  female  the  uterus  will  be  seen  resting 
upon  the  rectum,  and  sending  a  prolongation — cornu  or  horn — 
cephalad  on  each  side  toward  the  kidney. 


PERITONEUM, 


279 


ABDOMINAL  TISCERA,   SPECIAL  STUDY. 

§  724.  Names  of  Farts  in  the  Order  of  Examination. — Perito- 
neum ;  Diaphragma,  diaphragm ;  Stomaclius,  stomacli ;  Splen, 
spleen ;  Intestinum  tenue,  small  intestine  (duodenum,  jejunum, 
ileum)  ;  Intestinum  ampin m,  large  intestine  (caecum,  colon,  rec- 
tum) ;  Hepar,  liver ;  Pancreas  ;  Ren,  kidney ;  Urocystis,  urinary 
bladder ;  Adrenal,  suprarenal  capsule  ;  Uterus,  womb  ;  Ovarium, 
ovary  ;  Vas  deferens,  spermatic  duct. 

Instruments  and  material  the  same  as  for  the  general  study. 

Specimen. — The  same  specimen  may  be  used,  or  if  a  different 
one  is  used,  it  should  be  prepared  in  the  same  way  (§  709). 


PERITONEUM. 

§  735.  Peritoneum. — The  peritoneum  is  a  serous  sac  lining  the  abdomen.  It  gives 
the  ental  aspect  of  the  abdominal  wall  its  smooth,  glistening  appearance.  It  may  be  sep- 
arated easily  from  the  abdominal  wall  over  a  small  area  with  the  tracer. 

The  peritoneal  sac  is  closed  in  the  male,  but  in  the  female  the  Fallopian  tubes  open 
into  it,  and  hence  it  communicates,  through  these,  with  the  exterior. 

The  mesenteries  and  the  ligaments  of  the  liver,  urocystis  and  uterus  are  formed  by 
duplicatures  of  the  peritoneum. 

All  the  organs  of  the  abdomen  are  really  outside  of  the  sac.  The  apparent  presence  of 
some  of  the  organs  within  it,  and  the  way  in  which  the  mesenteries  are  formed,  may  be 
readily  understood  from  the  following  diagram  (Fig.  78). 

This  diagram  represents  an  ideal  transection  of  the 
cat's  abdomen  at  the  level  of  the  kidneys.  The  kidneys 
{ren)  are  represented  as  projecting  somewhat  into  the 
abdominal  cavity,  and  covered  only  on  their  ventral  sur- 
face by  the  peritoneum.  The  alimentary  canal  {Alt. 
canal),  shown  also  in  cross  section,  is  represented  as 
having  moved  far  ventrad  into  the  abdominal  cavity, 
carrying  with  it  a  fold  of  peritoneum  which  forms  the 
mesentery  (§  726). 

§  726.  The  word  mesentery  is  often  used  in  a  general 
way  to  indicate  any  of  the  duplicatures  of  peritoneum 
supporting  the  intestines  ;  but  strictly  speaking,  the 
term  refers  only  to  the  duplicature  of  peritoneum  sup^ 
porting  the  portions  of  the  small  intestine  known  a& 
jejunum  and  ileum.  The  proper  term  for  the  peritoneal 
duplicature  of  any  other  part  of  the  intestine  is  formed 
by  prefixing  meso  to  the  name  of  the  part ;  thus,  meso- 
duodenum,  mesocolon,  mesorectum,  etc. 


Fig.  78.— Diagram  showing 
THE  Relations  op  the 
Abdominal  Organs  and 
the  Peritoneum. 


As  shown  in  Fig.  78,  the  mesenteries  and  ligaments  are  double 
walled  membranes.     Demonstrate  this  by  tearing  away  the  mem- 


280  •     ANATOMICAL    TECHNOLOGY. 

brane  covering  one  side  of  a  blood  vessel.     A  similar  membrane 
will  remain  on  the  opposite  side. 

§  727.  Omentum  majus,  epiploon,  a^.— Caul  (§  716).— The  epi- 
ploon is  a  double  walled  sac  formed  by  a  duplication  of  a  double 
fold  of  peritoneum.  The  cavity  of  this  sac  is  sometimes  called  the 
lesser  peritoneal  camty.  Demonstrate  the  sac-like  character  of  the 
omentum  by  tearing  it  open  and  divaricating  the  two  walls.  Dem- 
onstrate that  each  wall  of  the  sac  is  composed  of  two  layers,  as  with 
the  mesentery,  by  tearing  away  one  layer  with  the  tracer.  This 
may  be  most  easily  and  satisfactorily  done  over  a  blood  vessel  or  a 
strip  of  fat. 

It  will  be  seen  from  the  above  that  the  omental  sac  as  it  lies 
collapsed  on  the  intestines  consists  oi  four  thiclcnesses  of  perito- 
neum. 

§  728.  Foramen  Winslovii,  az. — Foramen  of  Winslow. — This  is 
the  contracted  mouth  of  the  omental  sac  through  which  it  communi- 
cates with  the  general  peritoneal  cavity.  It  is  relatively  larger  than 
in  man,  and  may  be  easily  demonstrated  by  tearing  open  the  sac 
near  the  pylorus,  lifting  the  two  walls  slightly  and  divaricating 
them.  There  will  be  seen  within  the  sac  a  small  lobe  of  the  liver 
{lohus  Spigelii)^  and  at  the  caudal  margin  of  this  lobe,  sometimes 
partly  filled  by  it,  will  be  seen  the  foramen.  It  is  about  2  cm.  hi 
diameter,  and  is  on  the  dorsal  side  of  the  ductus  communis  chole- 
docTius  and  Vena  portce.  The  foramen  may  likewise  be  demon- 
strated by  turning  the  duodenum  to  the  left  and  finding  the  ductus 
choledochus  and  Vena  portse.  This  should  be  done  in  a  perfectly 
fresh  and  uninjured  specimen,  and  the  omental  sac  inflated  by 
blowing  into  the  foramen  with  a  bent  glass  tube  or  a  large  flexible 
blow-pipe. 

§  729.  The  Obmoxis  Structure  of  the  peritoneum  is  like  that  of  serous  membranes  gen- 
erally— thin  and  transparent,  smooth  and  glistening. 

§  730.  Microscopic  Structure. — (A)  Ectal  layer  of  a  single  thickness  of  flattened  nu- 
cleated cells.  (B)  Attached  or  ental  layer  of  connective  tissue  containing  elastic  and 
white  connective  tissue  fibers.     Consult  Frey,  A  ;  Quain,  A,  II,  197  ;  Strieker,  A,  509. 

§  731.  Glandulae  Mesentericae,  a^.— Mesenteric  glands. — The 
so  called  mesenteric  glands  belong  to  the  lymphatic  system.  They 
are  between  the  layers  of  mesentery,  and  are  especially  large  near 
the  ctecum,  some  of  them  being  1-2  cm.  thick  and  3  cm.  long. 


THE    STOMACH. 


281 


§  732.  Corpuscula  Pacini,  az. — Pacinian  corpuscles. — These  are 
oval  bodies  about  2  mm.  long  and  1  mm.  thick.  They  are  between 
the  layers  of  mesentery,  and  may  be  demonstrated,  in  lean  cats,  by 
lifting  the  mesentery  and  looking  through  it  toward  the  light.  They 
appear  as  translucent  thickenings  of  the  form  and  size  mentioned 
above. 

§  783.  Microscopic  Structure. — (A)  K  connective  tissue  envelope.  (B)  Many  concen- 
trically arranged  layers  of  translucent  connective  tissue.  (C)  A  semifluid,  richly  nucleated, 
central  mass.  (D)  The  termination  of  a  single  meduUated  nerve  fiber.  (E)  A  capillary 
network  of  blood  vessels.     Strieker,  A,  179  ;  Quain,  A,  II,  150. 


Fig.  79. — Stomach  and  Duodenum,  Ventral  View  ;    x  1. 


§  734.  Diaphragma,  az. — Diaphragm  (Fig.  90,  §  712).— Draw 
the  stomach  and  liver  somewhat  caudad,  and  with  a  sharp  scalpel 
perforate  the  diaphragm,  provided  the  thorax  was  not  opened  to 
make  the  injection.  This  will  allow  the  air  to  enter  the  thorax,  and 
the  stomach,  etc.,  may  be  kept  in  view.  The  diaphragm  is  fully 
considered  in  §  816. 

Preparation— Fig.  79.— The  cat  was  fed  a  moderate  amount  of 
eolid  food  about  an  hour  before  death.     After  death,  the  stomach 


282  ANATOMICAL    TECHNOLOGY. 

was  filled  from  the  duodenum  moderately  with  95  per  cent,  alcohol. 
The  omentum  and  mesentery  were  then  carefully  removed  ;  the 
pancreatic  and  hepatic  ducts  isolated  for  a  short  distance  ;  the  chol- 
ecyst  carefully  separated  from  the  liver  ;  then  the  oesophagus  was 
separated  from  the  diaphragm  and  ligatured  about  2  cm.  cephalad 
of  it.  The  duodenum  was  also  ligatured,  and  then  the  whole  was 
put  into  95  per  cent,  alcohol  for  two  days.  The  ventral  portion  was 
then  removed,  as  shown,  with  a  sharp  scalpel,  and  the  contents 
washed  out. 

Description  of  Fig.  79. — Cholecystis. — Gall  bladder.  Curvatura  major.— The 
greater  curvature  of  the  stomach.  Curvatura  minor.— The  lesser  curvature  of  the  stom- 
ach. Dct.  (ductus)  hepaticae. — Hepatic  ducts.  Dct.  (ductus)  choledochus  commu- 
nis. Dct.  Wirsung.,  Ductus  Wirsungianus. — The  pancreatic  duct  opening  into  the 
ampulla  of  Vater.  Dct.  (ductus)  Santorini. — The  pancreatic  duct  opening  independently 
into  the  intestine.  Duodenum. — §  738.  Fix.  impd.,  Flexurae  impedentes. — The  im- 
peding flexures  of  the  cystic  duct.  (Esophagus. — §  735.  Ppl.  amp.  Vtr.,  Papillae 
ampullae  Vateri.  Pylorus. — §  735,  C.  Regio  cardiaca. — The  cardiac  region,  tlie  region 
next  the  diaphragm.     Regio  pylorica. — The  pyloric  region.     Rugae. — Folds. 

§  735.  Stomachus,  a^.— Stomach  (Fig.  79,  §  714). — Demonstrate 
thefollowing : — (A)  The  abdominal  oesophagus.  Turn  the  left  lobe 
of  the  liver  cephalad,  and  the  abdominal  oesophagus  will  be  seen 
emerging  from  the  diaphragm  and  entering  the  cephalic  or  cardiac 
end  of  the  stomach. 

From  the  nearly  cephalo-caudal  direction  of  the  dorsal  part  of 
the  diaphragm,  the  dorsal  side  of  the  cardiac  end  of  the  stomach  is 
applied  closely  to  it,  and  hence  there  is  an  abdominal  oesophagus 
only  on  the  ventral  side. 

(B)  The  stomach  as  a  whole  is  pear-shaped  and  curved  upon 
itself.  The  curvatura  major,  or  great  curvature,  faces  sinistro- 
caudad,  and  the  great  omentum  is  attached  to  it.  The  curvatura 
minor^  or  lesser  curvature,  looks  dextro-cephalad,  and  there  is 
attached  to  it  the  lesser  omentum. 

The  larger  or  cardiac  end  is  next  the  diaphragm  and  receives  the 
oesophagus.  The  pyloric  or  smaller  end  is  curved  sharply  upon 
itself,  and  is  partly  concealed  on  its  ventral  side  by  the  liver. 

(O)  Pylorus  or  pyloric  valve  (Fig.  79).— This  is  between  the 
stomach  and  small  intestine.  It  usually  appears  as  an  annular  con- 
striction, and  is  firm  to  the  touch.  The  pylorus  in  the  cat,  as  in 
man,  is  a  ring-like  fold  of  mucous  membrane  and  a  spliincter  mus- 
cle formed  by  an  increase  in  thickness  of  the  general  layer  of 
circular  muscular  fibers  of  the  alimentary  canal. 


THE    S3IALL    INTESTINE.  283 

The  general  appearance  may  be  demonstrated  by  making  a 
longitudinal  section  of  the  pylorus  and  small  intestine  as  shown  in 
Fig.  79. 

§  736.  Obvious  Structure  of  the  Stomach. — With  a  scalpel,  make  a  longitudinal  incision 
in  tlie  stomach  along  its  entire  ventral  surface,  and  wash  out  the  contents.  With  scis- 
sors, cut  out  a  pieco  of  the  stomach  2-3  cm.  square.  Look  at  the  cut  edge  with  a  tripod 
magnifier  after  observing  it  well  with  the  naked  eye.  It  will  be  seen  to  be  composed  of 
two  very  obvious  coats,  an  ectal,  firm  muscular  coat,  covered  by  the  thin  peritoneum,  and 
an  einal,  soft  mucous  coat.  These  are  somewhat  loosely  connected  together,  and  if  the 
stomach  is  empty  or  but  slightly  filled,  the  mucous  coat  will  be  thrown  into  folds  or  TugoB, 
mostly  longitudinal  in  direction,  by  the  contraction  of  the  muscular  coat. 

Microscopic  Structure,  commencing  ectad  : — (A)  Peritoneal  or  serous  coat.  (B)  Muscu- 
lar (unstriped)  coat  of: — (1)  Ectal  longitudinal  layer;  (2)  intermediate  circular  layer; 
(3)  ental  oblique  layer.  (C)  Submucosa,  loose  connective  tissue  coat.  (D)  Muscularis 
mucosae,  a  thin  layer  of  unstriped  muscular  fibers  both  circularly  and  longitudinally 
arranged.    (E)  Mucous  coat,  with  peptic  glands.     See  Strieker,  A,  370  ;  Quain,  A,  II,  350. 

§  737.  Splen,  az. — Spleen  (§  715). — The  relations,  form  and  tex- 
ture of  the  spleen  should  be  carefully  noted.  It  is  one  of  the  so 
called  ductless  glands,  and  its  functions  are  not  well  understood. 

§  738.  Intestinum  tenue,  az. — Small  intestine  (Fig.  77,  §  717).^ 
The  small  intestine  is  arbitrarily  divided  into  three  regions :  The 
duodenum^  the  jejunum  and  the  ileum, 

(A)  Duodenum. — That  part  of  the  small  intestine  along  which  the 
pancreas  extends  is  called  the  duodenum.  It  is  held  rather  firmly 
in  position  by  a  ligament  from  its  caudal  end.  Into  the  duodenum 
empty  the  ductus  cJioledochus  communis  (Fig.  81  and  82)  and  the 
two  pancreatic  ducts. 

(B)  Jejunum. — This  is  an  ill-defined  portion  of  the  small  intes- 
tine immediately  following  the  duodenum.  It  is  so  called  because 
in  man  it  is  often  found  empty  after  death. 

(C)  Ileum. — Tliis  is  the  caudal  part  of  the  small  intestine,  and  is 
a  continuation  of  the  jejunum,  as  that  is  of  the  duodenum.  It  ter- 
minates in  the  large  intestine,  entering  it  obliquely.  At  its  termina- 
tion is  the  ileo-ccEcal  valve^  which  allows  the  alimentary  contents  to 
pass  from  the  small  to  the  large  intestine,  but  not  easily  in  the 
opposite  direction.  The  action  of  this  valve  may  be  demonstrated 
by  cutting  a  slit  in  the  small  intestine  5-10  cm.  cephalad  of  its  ter- 
mination, and  injecting  water  caudad.  The  water  will  pass  readily 
into  the  large  intestine. 

Now  cut  a  small  slit  in  the  large  intestine  and  inject  water  toward 
the  small  intestine.  It  will  pass  with  difficulty  into  the  small  in- 
testine. 


284 


ANA  TOMICAL     TECHNOL  OGY. 


Preparation— Fig.  80.— A  cat  which  has  been  well  fed  five  or 
six  hours  before  death  is  best.  The  mesentery  should  be  removed, 
and  about  10  cm.  of  the  small  and  the  same  length  of  the  large 
intestine  should  be  left  with  the  caecum  and  ileo-csecal  valve.    The 

contents  of  both  large  and 
small  intestine  should  be 
carefully  removed  and  the 
large  intestine  ligatured. 
Then  both  should  be  mod- 
erately distended  by  inject- 
ing 95  per  cent,  alcohol  into 
the  small  intestine.  The 
latter  should  then  be  liga- 
tured and  the  whole  put  into 
95  per  cent,  alcohol.  After 
two  to  three  days  the  walls 
may  be  removed  with  a 
sharp  scalpel. 

Caecum,  as.— See  §  742,  A.  Colon, 
«s.— See  §  742,  B.  Ileum,  as.— See 
§  738.  Sphincter,  as.- See  §  739. 
Villi.— See  §  740,  B.  Valvaileo-caeca- 
lis,  az. — Ileo-caBcal  valve.    See  §  739. 


Fig.  80.— Caecum  and  Ileo-c^cai*  Valve,  Ven- 
tral View  ;  x  1. 


§  739.  Valva  ileo-caeca- 
lis. — The  ileo-csecal  valve  in 
the  cat  is  quite  unlike  its 
homologue  in  man.  In  the  cat  it  is  a  sphincter,  composed  of  circu- 
lar muscular  fibers  like  the  pylorus,  and  like  the  pyloric  valve  it  is 
partly  formed  by  an  annular  fold  of  mucous  membrane,  which  in 
the  ileo-csecal  valve  projects  into  the  large  intestine  (Fig.  80). 

The  thickest  part  of  the  sphincter  is  about  1  cm.  cephalad  of  the 
opening  into  the  large  intestine.  The  villi  are  not  present  caudad 
of  this  point,  hence  about  1  cm.  of  the  mucous  membrane  of  the 
small  intestine  of  the  cat  is  devoid  of  villi. 


§  740.  Obvious  Structure. — (A)  Cut  out  two  or  three  square  cm.  of  any  part  of  the 
small  intestine  ;  rinse  it  with  water  if  necessary  ;  it  will  be  seen  to  be  composed  of  two 
obvious  coats  like  the  stomach  (§  736). 

(B)  Villi  intestinorum. — Put  a  fresh  piece  of  intestine  in  a  watch  j?lass  of  water  or 
normal  salt  solution,  and  look  at  the  m«cous  surface  in  profile.  There  will  appear  numer- 
ous slender  finger-like  processes  with  their  free  ends  pointing  toward  the  lumen  of  the 


THE    LARGE    INTESTINE.  385 

intestine.  These  are  the  intestinal  villi.  They  are  only  found  in  the  small  intestine,  and 
are  most  abundant  in  its  cephalic  portion. 

The  small  intestine  of  the  cat  has  no  valvulse  conniventes  (Quain,  A,  359  ;  Gray,  A, 
773) ;  but  it  is  completely  invested  by  peritoneum  throughout  its  whole  extent.  In  these 
two  particulars  it  differs  from  the  intestine  of  man, 

§  741.  Microscopic  Structure. — (A)  Peritoneal  or  serous  coat.  (B)  Muscular  (unstriped) 
coat :— (1)  Longitudinal  layer  ;  (2)  circular  layer.  (C)  Submucosa,  areolar  or  loose  con- 
nective tissue  coat.  (D)  Muscularis  mucosae  of  longitudinal  and  circular  unstriped  muscu- 
lar fibers,  some  of  which  pass  into  the  villi.  (E)  Mucous  coat  with  villi  and  crypts  of 
Lieberkiihn,  covered  with  columnar  epithelium ;  Brunner's  glands  and  Peyer's  glands. 
Quain,  A,  II,  358  ;  Strieker,  A,  380. 

§  742.  Intestinum  amplum,  a^.— Large  intestine  (Fig.  77,  §  719). 
— The  large  intestine  is  the  part  of  the  alimentary  canal  extending 
from  the  csecnm  to  the  anus,  the  caudal  opening  of  the  canal.  For 
convenience  of  description,  the  large  intestine  is  divided  into  four 
parts,  named  in  order : — CcBcum,  colon  ascendens^  colon  iransver- 
sum^  colon  descendens  and  rectum  or  terminal  part. 

Exposure. — Turn  the  small  intestine  toward  the  left  leg. 

(A)  CcBcum  (Fig.  80). — This  is  the  somewhat  conical  blind  sac  at 
the  beginning  of  the  large  intestine.  It  lies  on  the  right  side  and  in 
about  the  middle  of  the  abdominal  cavity. 

(B)  Colon  ascendens — Ascending  colon. — This  is  the  part  of  the 
large  intestine  wbich  extends  cephalad  from  the  csecum. 

Respecting  the  use  of  the  terms  cephalad  and  caudad  in  desig- 
nating the  position  or  direction  of  parts  of  the  alimentary  canal, 
see  §  91. 

Topographically  J  the  colon  ascendens  extends  cephalad  from 
the  csecum,  but  pJiysiologically,  that  is,  in  respect  to  the  passage 
of  the  contents,  the  entire  colon  is  caudad  of  tbe  csecum. 

It  is  quite  short,  and  reaches  nearly  to  the  pylorus.  Its  dorsal 
surface  is  in  contact  with  the  duodenum. 

(C)  Colon  transfer  sum — Transverse  colon. — This  is  the  continua- 
tion of  the  preceding.  It  extends  transversely  across  the  abdomen 
just  caudad  of  the  stomach. 

(D)  Colon  descendens  and  rectum. — After  extending  nearly 
across  the  abdomen  from  right  to  left,  the  large  intestine  passes 
obliquely  caudad,  soon  reaching  the  meson.  It  then  extends  cau- 
dad along  the  vertebral  column  to  terminate  at  the  anus.  The  last 
and  straighter  part  is  called  the  rectum. 

§  743.  Ohvious  Structure  of  the  Intestinum  amplum. — If  the  large  intestine  is  full  of 
feces,  press  the  contents  of  a  small  part  of  the  colon  transversum  aside  and  cut  out  a  piece 


286  ANATOMICAL    TECHNOLOGY. 

1-3  cm.  square.  Rinse  the  mucous  surface  with  water  or  normal  salt  solution .  The 
structure  will  appear  like  that  of  the  small  intestine  except  that  villi  are  absent. 

Microscopic  Structure  of  the  Intestinum  amplum.—{A)  Peritoneal  or  serous  coat.  (B) 
Muscular  (unstriped)  coat  : — (1)  Longitudinal  layer  ;  (2)  circular  layer.  (C)  Submucosa, 
loose  connective  tissue  coat.  (D)  Muscularis  mucosae,  unstriped  muscular  fibers  arranged 
both  longitudinally  and  transversely.  (E)  Mucous  coat,  containing  crypts  of  Lieberkiihn 
and  Peyer's  glands. 

The  large  intestine  of  the  cat  is  completely  invested  by  peritoneum,  and  is  supported 
by  a  duplicature  of  the  same ;  hence  in  these  respects  it  differs  somewhat  from  man.  See 
Strieker,  A,  391 ;  Quain,  A,  II,  371. 

§  744.  Hepar,  a^.— Liver  (Fig.  77,  §  713).— Grasp  the  liver  with  the 
hand  and  draw  it  in  various  directions.  It  is  deeply  divided  (lobed) 
and  is  supported  in  various  parts  by  folds  of  peritoneum,  the  so 
called  ligaments  of  the  liver. 

LoM  Jiepatici. — The  lobes  of  the  feline  liver  have  not  been  satis- 
factorily homologized  with  those  of  the  human  liver,  and  the  nomen- 
clature is  somewhat  unsettled.  (Owen,  A,  III,  485  ;  Flower,  41). 
For  convenience,  the  following  provisional  names  may  be  used  : — 

(A)  Lohus  sinister.— This  part  of  the  liver  is  at  the  left  of  the 
suspensory  ligament  (the  ligament  parallel  with  the  meson  and  serv- 
ing to  hold  the  liver  against  the  diaphragm).  This  lobe  is  deeply 
divided,  and  its  caudal  or  thin  edge  is  on  the  ventral  side  of  the 
pyloric  region  of  the  stomach  (Fig.  79). 

(B)  Lobus  cysticus — Cystic  lobe. — This  is  at  the  right  of  the  sus- 
pensory ligament,  and  occupies  the  right  ventral  part  of  the  abdo- 
men. It  contains  the  cholecyst  or  gall  bladder,  and  hence  cannot 
be  mistaken.  It  is  in  some  cases  deeply  divided,  and  in  others  only^ 
slightly. 

(C)  Lohus  dexter — Kight  lobe. — This  is  dorsad  of  the  cystic  lobe. 
It  is  usually  deeply  subdivided,  and  is  in  contact  with  the  ventral 
aspect  of  the  right  kidney. 

(D)  Lohus  Spigelii. — This  is  the  smallest  of  the  lobes  of  the  liver. 
It  is  dorsad  of  the  left  lobe  and  dextro-cephalad  of  the  lesser  curva- 
ture of  the  stomach.  It  usually  appears  at  the  mouth  of  the  fora- 
men of  Winslow,  and  may  be  fully  exposed  by  tearing  away  the 
peritoneum  (§  728)  at  the  lesser  curvature  of  the  stomach. 

§  745.    Cholecystis—QdiW  bladder. — This  is  a  receptacle  for  bile, 
and  as  stated  above  is  partly  imbedded  in  the  cystic  lobe.    It  is  a- 
pear-shaped  sac,  and  the  larger  end  usually  appears  on  the  ventral 
surface  of  the  cystic  lobe  (Fig.  77).     To  expose  it  fully,  turn  the  free 
edge  of  the  cystic  lobe  cephalad. 


DUCTS    OF   THE    LIVER,  287 

§  746.  Ductus  hepatici — Bile  ducts. — Press  on  the  cliolecyst, 
and  the  contained  bile  will  be  forced  into  the  various  bile  ducts : — 

(1)  Ductus  cysticus. — This  is  the  duct  extending  from  the  small 
end  of  the  cholecystis  to  the  ductus  communis  (3).  It  presents  sev- 
eral loops,  tlie  so  called  impeding  flexures,,  and  serves  to  conduct 
the  bile  to  or  from  the  cholecyst  (Fig.  79,  81,  82). 

(2)  Ductus  hepatici  (Fig.  79). — These  are  the  bile  ducts  proper. 
They  convey  the  bile  from  the  various  lobes  of  the  liver  to  the  duc- 
tus communis  (Fig.  79,  81).  Press  on  the  cholecystis  again  if  neces- 
sary to  make  them  evident.  Isolate  one  by  means  of  the  tracer. 
Cut  a  Y-shaped  slit  in  it  near  its  end  and  press  all  of  the  bile  in  the 
cholecyst  out  through  the  slit.  Then  insert  a  canula  through  this 
slit  and  inject  toward  the  cholecyst  with  plaster  (§  359).  This  will 
fill  all  the  ducts  as  well  as  the  cholecyst,  and  after  the  plaster  has 
set  they  may  be  traced  in  the  same  way  as  arteries,  (§  596  [10]). 

(3)  Ductus  cJioledocJius  communis — The  common  bile  duct. — 
As  the  name  implies,  this  receives  all  of  the  other  ducts  from  the 
liver.  It  appears  to  be  a  continuation  of  the  cystic  duct.  It  reaches 
the  duodenum  about  3  cm.  from  the  pylorus,  and  enters  it  obliquely 
caudad.  Within  the  walls  of  the  duodenum,  it  empties  into  a  small 
reservoir  {ampulla  of  Vater),  common  to  it  and  the  duct  of  Wir- 
sung  (Fig.  84). 

The  character  of  the  opening  of  the  ductus  choledochus  and  its 
relation  to  the  ductus  Wirsungianus  are  shown  in  Fig.  84. 

§  747.  Obvious  Structure  of  the  Liver  (liepar). — (A)  LoJn. — The  liver  is  composed  of  sev- 
eral deep  red  lobes,  which  are  smooth  and  shining  on  the  surface  from  the  presence  of  the 
peritoneal  investment.  This  is  very  thin  and  is  separated  with  difficulty,  even  over  small 
areas. 

(B)  Ldbuli — Lobules. — These  are  plainly  visible  as  small  areas  about  1  mm.  in  diam- 
eter, surrounded  by  rings  of  deeper  color. 

(C)  Parenchyma. — If  a  piece  is  cut  out,  it  may  be  readily  crushed  into  a  pasty  mass, 
showing  that  the  structure  is  pulpy  and  cellular  rather  than  fibrous. 

§  748.  Microscopic  Structure, — (A)  Peritoneal  or  serous  coat.  (B)  Fibrous  coat  (pro- 
jections of  this  accompany  the  vessels).  (C)  Liver  substance  ;  this  consists  of  lobules 
composed  of  polyhedral  cells  arranged  in  a  radiate  manner  around  the  center  of  the  lobule. 

Vessels  of  the  Lobule, — (1)  Intralobular  vein  or  hepatic  veinlet  in  the  center  of  the  lob- 
ule ;  (2)  Interlobular  or  portal  veinlet  and  the  hepatic  arteriole.  These  are  between  the 
lobules,  and  capillaries  pass  from  them  to  the  center  of  the  lobule  between  the  rows  of 
hepatic  cells.  In  addition  to  the  above,  are  the  beginnings  of  the  hepatic  ducts.  ?ee 
Strieker,  A,  407  ;  Qnain,  A,  II,  386. 

§  749.  Pancreas,  az.  (Fig.  81,  §  720).— The  cat's  pancreas  is 
greatly  elongated,  and  so  bent  as  to  form  two  sides  of  a  triangle. 


288 


ANA  TOMICAL    TECENOL  OGY. 


From  the  relations  of  the  two  parts,  they  are  called  respectively  the 
gastro- splenic  and  the  duodenal  parts  of  the  pancreas  (Owen,  A, 
III,  495).  The  organ  is  wholly  enveloped  by  peritoneum,  thus  dif- 
fering from  the  human,  which  is  covered  by  peritoneum  only  on  its 
ventral  surface. 

In  order  to  expose  the  pancreas  fully,  the  ventral  wall  of  the 
great  omentum  should  be  removed,  and  the  large  and  small  intes- 
tines  should  be  drawn  caudad. 


Fig.  81.  —  Ventral 
View  of  the  Pan- 
creas AND  ITS 
Ducts  :    x  1. 


Like  the  human  pancreas,  that  of  the  cat  has  two  dLUai^— Ductus 
Wirsungianus  and  Ductus  Santorini-^which  open  separately  into 
the  intestine,  although  they  anastomose  in  the  substance  of  the 
pancreas  (Fig.  81-83). 

Preparation— Fig.  81.— TJie  great  omentum,  the  jejunum,  ileum, 


CHOLECYSTIS    AND    PANCREATIC    BESERVOIR. 


589 


colon  and  liver  were  removed  ;  the  remaining  parts  shown  in  situ. 
The  duct  of  Wirsung  was  afterward  injected  with  Berlin  blue,  and 
both  it  and  the  duct  of  Santorini  dissected  out  to  show  their  branches 
and  anastomoses. 

Explanation  of  Fig.  8i. — 1.  Pyloric  region  of  tlie  stomach. 

2.  Pylorus.     2-3.  The  duodenum. 

4.  G astro-splenic  division  of  the  pancreas,  near  the  main  branch  of  the  duct  of  Wirsung. 

/).  The  duodenal  part  of  the  pancreas  and  branch  of  the  duct  of  Wirsung. 

6.  Duodenum  at  the  point  where  the  duct  of  Santorini  pierces  its  walls.  The  dotted 
line  shows  the  extent  of  the  pancreas  on  the  dorsal  side  of  the  intestine.  The  duct  of  San- 
torini is  seen  to  anastomose  with  each  division  of  the  duct  of  Wirsung. 

7.  Ductus  communis  choledochus. 

8.  The  point  where  tlie  ductus  choledochus  and  the  duct  of  Wirsung  enter  the 
duodenum. 

9.  Tip  of  the  spleen,  somewhat  displaced. 

10.  Tlie  superior  mesenteric  artery  sending  the  inferior  pancreatico-duodenal  branch  to 
those  parts, 

11.  Superior  mesenteric  vein  receiving  a  corresponding  branck. 


Fig.  82.— Cholecystis  and  Pancreatic  Reseb- 
voir  and  their  connection  with  thb 
Duodenum  :    x  1. 


^    Preparation— Fig.  82.— The  liver  was  turned  to  the  right,  bring- 


290 


A N-A  TOMICAL    TECHXOL  0  G  Y. 


ing  the  concave  side  up  ;  the  duodenum  to  the  left,  so  that  its  rigiit 
side  looks  directly  upward  ;  it  was  then  sliced  off  to  the  level  of  the 
ampulla  of  Vater  and  the  duct  of  Santorini. 

Explanation  of  Fig.  82. — 1.  Pylorus. 

2.  The  duct  of  Santorini  passing  obliquely  through  the  duodenal  walls. 

3.  Cut  end  of  the  inferior  pancreaticoduodenal  artery. 

4.  Same  for  the  corresponding  vein. 

5.  The  duodenal  branch  of  the  duct  of  Wirsung. 

5.  Cut  end  of  the  duodenal  pancreas,  showing  triangular  section,  and  the  intestine 
partly  enveloped  by  it. 

6.  The  ampulla  of  Vater. 

7.  The  duct  of  Wirsung,  opening  into  the  ampulla. 

8.  The  ductus  communis  choledochus,  also  opening  into  the  ampulla. 

9.  The  duodenal  branch  of  the  duct  of  Wirsung. 

10.  The  gastro-splenic  branch  displaced. 

11.  Duct  from  the  pancreatic  reservoir  opening  by  a  large  branch  into  10,  and  by  a  small 
one  into  7. 

12.  Anomalous  pancreatic  reservoir  cov- 
-  // ^                                                  ering  part  of  the  cholecyst. 

13.  The  "  impeding  flexures "  in  the 
cystic  duct. 

14.  The  cholecystis  constricted  in  the 
middle,  as  is  also  the  pancreatic  reservoir, 
by  a  firm  wide  band  passing  over  them. 

15, 15.  The  cystic  lobe  of  the  liver. 

Preparation—Fig.  83.~The 
ventral  wall  of  the  duodenum 
was  partly  removed  to  show  the 
openings  of  the  ducts,  which  had 
"been  exposed  by  dissection. 

Explanation  of  Fig.  83. — 1.  Pylorus. 

2  and  4.  Duct  of  Wirsung. 

3.  Duct  of  Santorini  anastomosing  freely 
with  the  preceding,  and  opening  into  the 
intestine  between  the  aperture  of  the  am- 
pulla of  Vater  and  the  pylorus. 

5.  Ductus  communis  choledochus. 

6.  Opening  of  the  duct  of  Santorini  at  the  summit  of  a  papilla. 

7.  Opening  of  the  ampulla  at  the  sunimit  of  a  similar  papilla.     These  openings  are 
usually  about  10-15  mm.  apart. 


Fig.  83. — Ventral  View  op  the  Human 
Pancreatic  Ducts.  (After  Bernard, 
17).     X.5. 


§  750.  Ductus  Wirsimgianus — Duct  of  Wirsung,  principal  pan- 
creatic duct. — This,  in  tlie  cat,  is  usually  the  larger  of  the  two 
pancreatic  ducts,  as  in  man.    It  opens  into  a  small  reservoir,  am- 


I 


AMPULLA     OF    VATEE, 


291 


pulla  of  Vater,  within  the  walls  of  the  duodenum.  The  ampulla 
appears  as  an  oblique  elevation  on  the  ectal  surface  of  the  duode- 
num, and  receives  also  the  ductus  communis  choledochus  (Fig.  84). 

Preparation — Fig.  84. — ^The  duodenum  should  be  suspended  in 
95  per  cent,  alcohol  for  2-3  days,  or  it  may  be  hardened  in  MuUer's 
fluid  (see  Frey,  A).  Then  rather  thick  freehand  sections  may  be 
made  with  a  razor  or  a  very  sharp  scalpel.  The  sections  may  be 
studied  to  advantage  with  a  tripod  lens  or  with  a  |-in.  objective 
and  a  compound  microscope. 


'jDcrt. 


Cm.n. 


fiG.  84. — Longitudinal  Section  of  the  Ampulla  of  Vatbe,  showing  the  Entrance 
OF  THE  Ductus  Choledochus  and  the  Duct  op  Wirsung  ;  x  8.4.  A  and  B.— » 
Similar  Sections  of  the  Ampulla  op  Vater  in  Man.  (A  and  B,  after  Claude 
Bernard,  17).     x  1.75. 


Explanation  of  Fig.  84.— Ampulla,  Ampulla  of  Vater.— The  sac-like  space  in  tlie 

dl  of  the  duodenum  into  which  open  the  ductus  choledochus  and  the  ductus  Wirsungi- 

lus.     The  ampulla  is  not  a  free  space,  but  is  more  or  less  filled  by  anastomosing  processes 

)ringing  from  the  walls.     The  ampulla  opens  into  the  duodenum  through  a  single  orifice 

the  summit  of  a  slight  papilla. 

Dct.  chid,  cmn.,  Ductus  choledochus  communis,  az. — The  common  bile  duct. — It  i^ 

m  to  have  its  lumen  partly  filled  with  anastomosing  processes  which  allow  the  bile  to 

)w  into  the  ampulla,  but  tend  to  prevent  any  regurgitation. 

Dct.  Wirsung.,  Ductus  Wirsungianus,  «3  — Duct  of  Wirsung.— The  pancreatic  duct 

iptying  into  the  ampulla  of  Vater.     In  the  cat  it  is  usually  much  larger  than  the  duct 

Santorini  (Fig.  81-88). 


^93  ANATOMICAL     TECHNOLOGY, 

Mucosa.— The  mucons  membrane  of  the  small  intestine. 

M.  circularis.— The  circular  layer  of  unstriped  muscle. 

M.  longitudinalis.— The  longitudinal  layer  of  unstriped  muscles. 

Ost.  amp.  Vtr.,  Ostium  ampullae  Vateri,  az.—The  opening  or  mouth  of  the  ampulla 
of  Vater. 

Submucosa. — The  layer  of  connective  tissue  between  the  circular  muscle  and  the 
muscularis  mucosae. 

Fig.  84,  A  and  B. — Dct.  chid.,  Ductus  choledochus  communis,  az. — The  common 
bile  duct. 

Dct.  W.,  Ductus  Wirsungianus.— The  pancreatic  duct  opening  into  the  ampulla  of 
Vater.  In  A,  both  ducts  open  at  the  bottom  of  the  ampulla.  This  is  said  by  Bernard  to 
be  the  normal  condition.  In  B,  the  bile  duct  exteiKis  nearly  to  the  orifice  of  the  ampulla, 
as  in  the  cat.    This  is  not  common  in  man,  although  normal  in  the  cat. 

§  751.  Demonstration  of  the  Duct  of  Wirsungy  the  terminal 
part  of  the  Ductus  choledochus,  and  the  Ampulla  of  Vater, 

Turn  the  duodenum  to  the  left  and  trace  the  ductus  choledochus 
to  its  point  of  entrance  into  the  intestine.  Now  remove  the  perito- 
neal covering  on  the  dorsal  side  of  the  pancreas  just  caudad  of  tlie 
termination  of  the  ductus  choledochus.  Then  tear  away  the  sub- 
stance of  the  pancreas  very  carefully,  and  the  duct  will  be  exposed. 
It  looks  like  an  uninjected  blood  vessel.  Trace  it  for  some  distance 
from  the  intestine  and  it  will  be  found  to  divide  into  two  main 
branches,  one  for  each  part  of  the  pancreas  (Fig.  81-83).  Open  the 
duct  about  1  cm.  from  its  point  of  entrance  into  the  intestine,  and 
pass  a  beaded  bristle  into  it  toward  the  intestine.  With  a  sharp 
scalpel,  slice  away  the  intestine  over  the  point  of  entrance  of  the 
ductus  choledochus  communis  and  the  ductus  Wirsungianus,  mak- 
ing the  slices  parallel  with  the  direction  of  the  two  ducts.  Continue 
the  cutting  until  the  plaster  in  the  ductus  choledochus  and  the 
bristle  in  the  ductus  Wirsungianus  are  exposed.  It  will  be  seen 
that  the  two  ducts  penetrate  the  intestinal  wall  obliquely  caudad, 
and  open  separately  into  the  ampulla  (Fig.  84).  The  ampulla  then 
opens  through  a  slight  papilla  into  the  lumen  of  the  intestine. 

Contrary  to  the  common  statement,  the  two  ducts  cannot  be  said 
to  unite  at  all  (Gage,  3,  177). 

In  some  respects  it  is  better  to  employ  a  specimen  whose  hepatic 
ducts  have  not  been  injected  with  plaster  to  demonstrate  the  rela- 
tion and  termination  of  the  two  ducts.  In  this  case  a  bristle  should 
be  put  into  each. 

(B)  Ductus  Santorini— Lesser  pancreatic  duct  (Fig.  83).— Tliis, 
in  the  cat,  is  usually  much  smaller  than  the  preceding,  and  hence 
its  demonstration  is  more  difficult.     It  opens  on  the  left  side  of  the 


I 


THE    KIDNEYS. 


293 


intestine  obliquely  caudad  of  the  preceding,  and  is  demonstrated 
by  tearing  away  first  the  peritoneum  and  then  the  pancreatic  sub- 
stance. The  anastomosis  of  the  two  pancreatic  ducts  may  be  dem- 
onstrated by  injecting  the  ductus  Wirsungianus  peripherad  with 
Berlin  blue.  j 

§  752.  Obvious  Structure  oftJie  Pancreas, — It  is  composed  of  a  great  many  small  lob-^ 
ules  arranged  like  a  bunch  of  grapes,  tlie  ducts  representing  the  stems  of  the  grapes. 
Such  glands  are  said  to  be  racemose. 

%  753.  The  Microscopic  Structure  as  well  as  the  obvious  structure  is  in  all  essential 
particulars  like  that  of  the  salivary  glands  (§§  788,  789).  See  Strieker,  A,  295  ;  Quain,  A, 
II,  396. 

Hbn 


Fig.  85. — Dorso-ventral  Section 
OF  THE  Right  Kidney,  Caudal 
View  :   x  1.1. 


Fig.  86. — Longitudinal  Dextro-binistrai. 
Section  of  the  Right  Kidney,  Ven- 
tral View  :  x  1.1. 


i 


Preparation— Fig.  85,  86. — The  ureter  and  pelvis  were  inflated 
)y  injecting  95  per  cent,  alcohol  through  the  ureter  toward  the  kid- 
ley.  Then  the  ureter  was  ligatured  and  the  kidney  carefully 
iraoved  and  placed  in  60  per  cent,  alcohol  for  two  days,  then  in 
)5  per  cent,  alcohol  for  the  same  time.  When  well  hardened  it 
^as  sliced  off  to  the  level  shown  in  the  figures. 

Explanation  of  Fig.  85,  86.— Hilum.— The  concavity  of  the  mesal  border  of  the  kid- 
ney.    It  is  at  this  point  that  the  ureter  and  the  blood  vessels  enter. 

Papilla. — The  apex  of  the  medullary  portion.  From  its  free  end  the  urine  exudes. 
There  is  but  one  papilla  in  the  cat.  In  Fig  86,  the  medullary  portion  seems  to  end  by 
several  papillae,  but  the  pyramids  forming  these  converge  at  a  higher  level  than  here 
shown,  and  finally  end  as  shown  in  Fig.  85. 

Pelvis. — The  somewhat  dilated  space  into  which  the  papilla  opens. 

Substantia  medullaris. — The  medullary  or  central  part  of  the  kidney 

Tunica  fibrosa  (Fig.  85). — The  thick  fibrous  sac  enclosing  the  kidney.  It  is  reflected 
to  the  hilum  and  upon  the  ureter. 


294  ANATOMICAL    TECHNOLOGY, 

'  %  754.  Ren— Kidney  (Fig.  77,  78,  85,  86,  101,  103,  §  722).— Turn 
the  stomach  and  the  intestines  to  the  right,  and  the  left  kidney  will 
be  exposed.  Remove  any  fat  that  can  be  removed  without  displac- 
ing the  kidney.  Its  lateral  aspect  is  convex,  while  the  mesal  one 
presents  a  deep  concavity,  the  so  called  Mlum  of  the  kidney. 

The  right  kidney  is  somewhat  farther  cephalad  than  the  left, 
thus  differing  from  man.  Only  the  ventral  surface  is  covered  with 
peritoneum  (Fig.  78) ;  but  the  entire  kidney  is  surrounded  by  a 
special  fibrous  capsule  or  covering  (Fig.  85). 

Obvious  Structure  of  the  Kidney. — Witli  a  sharp  scalpel,  make  a  longitudinal  dextro- 
sinistral  section  of  the  kidney,  removing  the  ventral  three  fifths.  The  appearance  shown 
in  Fig.  86  will  appear. 

The  ureter  (§  756)  commences  as  a  funnel-shaped  opening  from  the  hollow  or  pelvic 
part  of  the  kidney  (Fig.  85,  86). 

The  solid  part  of  the  kidney  is  evidently  composed  of  two  portions — the  ectal,  periphe- 
ral or  cortical,  and  the  entcU,  central  or  medullary  portions.  The  cortical  or  peripheral 
portion  is  granular  and  of  a  deep  color,  while  the  medullary  portion  is  lighter  in  color, 
smooth,  compact,  and  of  more  or  less  triangular  outline.  The  apex  projects  into  the  pelvis 
of  the  kidney  and  is  called  the  renal  papilla.  There  are  several  in  man,  but  only  one  in 
the  cat. 

§  755.  Microscopic  Structure. — (A)  Tubuli  uriniferi,  or  urinary  tubules — tubes  lined 
with  cells  and  forming  the  kidney  substance  proper.  (B)  Blood  'vessels  and  lymphatics. 
(C)  Nerves  and  connective  tissue. 

In  the  medullary  part  of  the  kidney,  the  blood  vessels  and  urinary  tubules  are  mostly 
straight  in  direction,  while  in  the  cortical  portion  they  are  looped  or  convoluted  ;  both 
vessels  and  tubules  are  branched.  The  arteries  form  the  so  called  glomeruli  or  Malpighian 
corpuscles  by  a  multiple  knotting  at  their  termination.  See  Strieker,  A,  460  ;  Quain,  A, 
II,  406. 

§  756.  Ureter.— Grasp  the  kidney  with  one  hand  and  the  uro- 
cyst  (Fig.  101)  with  the  other.  Draw  the  former  cephalad  and  the 
latter  caudad.  There  will  be  seen,  stretching  between  the  kidney 
and  the  neck  of  the  urocyst,  a  narrow  tense  band,  more  or  less  cov- 
ered with  fat.  This  band  is  the  ureter,  or  duct  conveying  the  urine 
from  the  kidney  to  the  urocyst. 

Sometimes  one  may  inflate  the  urocyst  by  blowing  into  the  renal 
end  of  the  ureter,  but  usually  the  ureter  is  too  greatly  contracted. 
The  tubular  character  of  the  latter  may  be  easily  demonstrated, 
however,  by  using  a  beaded  bristle  (§  136)  or  by  commencing  at  the 
kidney  and  slitting  it  with  fine  scissors. 

§  757.  Urocystis,  vesica  urinaria — Urinary  bladder  (Fig.  77, 
101,  §  718). — This  is  the  receptacle  for  the  urine. 

A.  Lig amentum  suspensorium. — Grasp  the  cephalic  or  larger 
free  end  of  the  bladder  and  draw  it  ventro-caudad.     A  thin  mem- 


I 


THE    UROCYST    OR    BLADDER.  295 


I 


brane  like  the  mesentery  will  be  seen  between  it  and  the  ventrime- 
son,  the  ligamentum  susjpensorium.  It  is  formed  of  a  duplicature 
of  peritoneum,  and  in  young  animals  there  may  be  seen  between 
its  two  layers  the  remnants  of  the  hypogastric  arteries  and  of  the 
radius  (Gray,  A  812  ;  Quain,  A,  II,  800). 

B.  Ligamentum  laterale. — In  addition  to  the  suspensory  liga- 
ment, one  having  tlie  same  general  appearance  will  be  seen  on  each 
side. 

C.  Cervix  urocystis — Neck  of  the  urinary  bladder. — Draw  the 
urocyst  caudad  and  its  fixed  point  will  be  seen  to  grow  narrow. 
This  narrow  part  is  the  neck^  and  its  continuation  to  the  exterior  is 
called  the  uretlira  or  excretory  canal  of  the  bladder.  The  ureters 
penetrate  the  urocyst  on  each  side  of  the  neck  ;  their  course  through 
the  w^all  is  quite  oblique,  as  may  be  demonstrated  by  passing  a 

ristle  from  the  ureter  into  the  bladder. 


§  758.    Obnious  Structure  of  the  Urocyst  — Cut  a  slit  in  the  urinary  bladder  to  allow  the 

urine  to  escape,  then  cut  out  a  piece  about  2  cm.  square.     Rinse  it  with  water  or  normal 

salt  solution.     There  may  be  demonstrated  a  structure  somewhat  comparable  to  that  of 

e  stomach  : — (A)  An  ectal  ssrous  (peritoneal)  coat.     (B)  An  intermediate  firm  or  muscu- 

r  coat,    (C)  An  ental  soft  or  mucous  coat.     The  muscular  and  mucous  coats  are,  how- 

er,  more  closely  united  than  in  the  stomach. 

§759.  Microscopic  Structure. — (A)  Serous  (peritoneal)  coat.  (B)  Muscular  (unstriped) 
t : — (1)  Longitudinal  layer  ;  (3)  circular  layer  ;  (3)  longitudinal  layer.  The  three  layers 
arranged  somewhat  in  the  form  of  a  figure  of — 8.  (C)  Submucosa  of  loose  connective 
sue.  (D)  Mucous  coat  covered  with  stratified  epithelium.  See  Strieker,  A,  487 ;  Quain, 
II,  423. 

§  760.   Adrenale — Capsula  renalis,  capsula  suprarenalis. — Turn 

le  stomach  and  intestines  to  the  right.     About  2  cm.  meso-cephalad 

the  kidney  will  appear  a  pinkish,  oval  body  about  2  cm.  long 

tnd  1  cm.  wide.     Its  caudal  end  is  usually  in  contact  with  the  V. 

mails  and  its  ventral  surface  is  crossed  by  the  V.  adreno-lumbalis 

'ig.  101,  adrn.). 

The  right  adrenal  is  in  about  the  same  position  with  respect  to 
le  right  kidney  ;  but  as  the  V.  cava  and  part  of  the  liver  are  on  its 
fentral  surface,  it  is  not  so  easily  demonstrated  as  the  left. 

Both  adrenals  are  covered  on  their  ventral  surface  by  perito- 
5um.  Neither  of  them  is  in  contact  with  the  kidney.  In  this 
aspect  they  differ  from  their  human  homologues. 

§  761.  Uterus— Womb  (§  723).— If  the  cat  is  a  female,  there  will 
ippear  between  the  rectum  and  the  urocyst  a  mesal  organ,  the 
uterus,  having  the  same  general  color  and  appearance  as  the  intes- 


296  ANA  TOMICA  L     TECHNOL  OGY. 

tines.  It  is  a  hollow  organ  and  at  its  cephalic  end  bifurcates, 
forming  the  so  called  cornua  or  horns  of  the  uterus.  The  horns 
extend  obliquely  latero-cephalad  nearly  to  the  caudal  extremity  of 
the  corresponding  kidney  (Fig.  77). 

§  762.  Tuba  Fallopiana — Fallopian  tube,  Oviductus.— Near  the 
ends,  the  horns  of  the  uterus  become  quite  small  and  more  or  less 
convoluted.  This  small  part  of  the  horn  is  called  the  omduct  or 
Fallopian  tube.  It  opens  directly  into  the  peritoneal  cavity,  thus 
putting  the  peritoneal  cavity  in  communication  with  the  exterior  of 
the  body.  The  end  is  somewhat  funnel  shaped  and  one  edge  is 
applied  to  the  ovary.    Quain,  II,  470. 

Make  an  incision  in  one  of  the  cornua  near  the  beginning  of  the 
Fallopian  tube  and  pass  a  beaded  bristle  into  the  uterus,  and  then 
along  the  Fallopian  tube  throughout  its  whole  extent.  This  will  be 
facilitated  by  severing  the  connections  of  the  tube  so  that  it  may  be 
straightened. 

§  763.  Ligamentum  uteri. — Grasp  a  uterine  comu  and  lift  it  up. 
A  broad  membranous  band  will  appear  extending  laterad  from  it. 
This  is  the  ligamentum  latum  or  broad  ligament  of  the  uterus  and 
its  horns.  Like  the  mesentery  and  ligaments  of  the  urocyst,  it  is 
simply  a  duplicature  of  peritoneum. 

Ligamentum  rotundum — Round  ligament. — Look  through  the 
ligament  toward  the  light ;  a  thickening  will  appear  in  it  extending 
from  near  the  middle  of  the  horn  caudad  to  the  abdominal  wall 
ventrad  of  Poupart'  s  ligament  (Fig.  39).  This  is  the  round  ligament, 
and  may  be  traced  through  the  abdominal  wall.  It  terminates  in 
the  external  organs  of  generation. 

§  764.  Obvious  Structure.— (A)  Serous  (peritoneal)  coat.  (B)  Muscular  coat.  (C)  A 
soft  mucous  coat.  These  points  may  be  easily  demonstrated  by  cutting  out  a  small  piece 
of  the  uterus  or  one  of  its  horns. 

§  765.  Microscopic  Structure.— (A)  /Sero?/s  (peritoneal)  coat.  (B)  Muscular  {nr\s{T]j)ed) 
coat  ;  the  fibers  greatly  interlace  and  are  mixed  with  abundant  connective  tissue.  (C) 
Mucous  coat.     See  Strieker,  A,  606  ;  Quain,  A,  II,  464. 

§  766.  Ovarium— Ovary.— At  the  cephalic  end  of  each  Fallo- 
pian tube  (§  762)  may  be  seen  the  ovary,  sl  yellowish  oval  body 
about  1  cm.  long  and  .5  cm.  wide.  It  is  supported  by  an -exten- 
sion of  the  broad  ligament. 

§  767.  Microscopic  Structure.— (A)  Modified  peritoneal  coat.  (B)  Ovarian  stroma— 
connective  tissue,  blood  vessels  and  nerves.  Graafian  follicles  with  the  ova.  See  Striclter, 
A,  510  ;  Quain,  A,  II,  472. 


THE    SALIVABY    GLANDS.  297 

§  768.  Vas  deferens. — If  the  subject  is  a  male,  there  will  be  seen 
on  each  side  a  white  cord,  the  vas  deferens  or  spermaduct  (Fig.  101), 
looping  around  the  ventral  side  of  the  ureter  and  A.  hypogastrica, 
and  then  extending  toward  the  urethra. 

If  the  vas  deferens  is  traced  peripherad,  away  from  the  urethra, 
it  will  be  seen  to  penetrate  the  abdominal  wall  laterad  of  the  A. 
epigastrica  and  ventrad  of  Poupart's  ligament. 

In  traversing  the  abdominal  wall,  it  passes  through  the  canalis 
inguinalis.  It  is  accompanied  by  the  spermatic  artery  and  vein 
and  a  duplicature  of  peritoneum,  and  all  together  form  the  sper- 
matte  cord.  The  opening  of  the  inguinal  canal  within  the  abdomi- 
nal cavity  is  called  the  annulus  abdominalis  internus  or  the  internal 
abdominal  ring,  while  the  one  on  the  ectal  surface  of  the  abdominal 
wall  is  called  the  annulus  abdominalis  externus  or  external  ab- 
dominal ring  (Fig.  39). 

From  the  external  abdominal  ring,  the  spermatic  cord  extends 
obliquely  caudad  and  entad  of  the  skin  to  the  testis. 

THE  SALIVARY  GLANDS,   MOUTH   CAVITY,  PHARYNX, 
NECK,   THORAX  AND  DIAPHRAGM. 

§  709. — Names  of  Parts  in  the  Order  of  Ei'ammntion.—G]n.ndn\3i  parotis — Ductus  Ste- 
nonianus  —  Glandula  submaxillaris — Ductus  Whartonianus  —  Lingua  —  Pharynx  —  Tuba 
Eustacliiana  —  Larynx  —  Trachea  —  (Esophagus  —  Pleura  —  Thymus  —  Pulmo — Cardia —  , 
Diaphragm  a. 

Tlie  vessels  and  nerves  of  these  parts  are  treated  in  Chap.  VIII  and  IX. 

§  770.  Instruments  and  Material  the  same  as  for  the  abdomen  with  the  addition  of  a 
saw  (Fig.  31),  nippers  (Fig.  11),  beaded  bristles  (§  136),  and  about  100  cc.  of  the  Berlin 
blue  solution. 

Choice  of  Specimen  the  same  as  for  the  abdomen. 

SALIVARY    GLANDS. 

§  771.  References.— Quain,  A,  II,  335  ;  Gray,  A,  757  ;  Bernard,  A,  504  ;  Chauveau, 
A,  387  ;  Leyh,  A,  373  ;  Owen,  A,  III,  396 ;  Cuvier,  A,  III,  409  ;  Hyrtl,  A,  341  ;  Gegen- 
baur  (Lank  ester).  A,  519  ;  Milne -Edwards,  A,  VI,  330  ;  Chauveaa  (Fleming),  A  ;  Gurlt, 
A,  361. 

§  772.  Posture  and  Preparation. — The  cat  should  be  dorsicum- 
bent,  with  a  block  crosswise  under  the  neck,  and  the  head  rotated 
dextrad  so  that  the  side  of  the  face  looks  upward  ;  the  mouth  should 
be  held  open  with  a  cork.  The  animal  should  be  injected  from  the 
femoral  artery,  making  the  plaster  somewhat  thinner  than  usual 
(§§  345,  352).     The  femoral  vein  should  be  injected  with  blue  plas- 


298  ANATOMICAL    TECUNOLOGY. 

ter  (§  362).  If  the  abdomen  is  not  to  be  used  (§  234),  it  is  easier  to 
inject  from  the  postcava  and  the  aorta  (§§  363,  365). 

As  plaster  will  not  pass  the  valves  in  the  veins,  it  is  best  for  this 
preparation,  as  for  Fig.  101,  to  inject  the  jugular  vein  with  line  blue 
mass  (see  §  1450)  instead  of  blue  plaster.  This  is  only  necessary, 
however,  for  permanent  preparations  or  for  special  demonstrations. 

§  773.  Salivary  Glands.— The  salivary  glands  are  the  organs, 
belonging  to  the  digestive  system,  which  secrete  the  saliva  and  pour 
it  into  the  oral  cavity  through  single  or  multiple  ducts.  They  are 
situated  in  close  proximity  to  the  mouth  and  mostly  just  entad  of 
the  skin.  There  are  5  on  each  side  '.—Parotid,  submaxillary^  sub- 
lingual, molar,  zygomatic. 

§  774.  Preparation  of  the  Ducts  of  the  Salivary  Glands. — 
These  should  be  injected  with  Berlin  blue  (see  §  1449),  or  if  that  is 
not  at  hand,  there  may  be  used  a  sufficient  quantity  of  chrome 
green  or  orange  ground  in  15  per  cent,  glycerin  to  give  a  decided 
color.  As  the  process  of  injection  is  somewhat  troublesome,  the 
ducts  may  be  demonstrated  by  inserting  into  them  beaded  bristles. 

§  775.  Preparation  of  WhartorC  s  Duct. — This  opens  on  the 
summit  of  a  prominent  papilla  situated  in  the  floor  of  the  mouth 
just  cephalad  of  the  frsenum  (Fig.  88).  It  usually  lies  on  the  floor 
of  the  mouth.  Grrasp  it  near  its  free  end  with  the  fine  forceps,  and 
enlarge  the  opening  with  the  probe  of  the  tracer ;  then  insert  a 
beaded  bristle  or  the  canula  for  injectitm  (§  358). 

Injection. — The  canula  need  not  be  tied,  but  merely  compiessed 
with  the  fingers  while  injecting.  Before  commencing  the  injection, 
the  canula  should  be  filled  with  the  injecting  mass  to  avoid  air.  In 
making  the  injection,  the  pressure  should  be  light  and  continued  for 
but  a  short  time  lest  the  duct  be  ruptured.  If  the  injection  is  suc- 
cessful and  the  tongue  be  turned  to  the  opposite  side,  the  duct,  may 
be  seen  in  the  floor  of  the  mouth  extending  nearly  parallel  with  the 
mandibidar  ramus  as  far  caudad  as  the  last  tooth. 

§  776.  Preparation  of  Btenovb  s  Duct. — With  coarse  forceps  or 
the  fingers,  grasp  the  dorsal  lip  near  the  angle  of  the  mouth  and 
draw  it  laterad  so  as  to  expose  the  mucous  membrane  opposite  the 
last  prsemolar  tooth  (Fig.  61).  Just  cephalad  of  the  angle  of  the 
mouth  and  opposite  the  most  prominent  cusp  of  the  last  prsemolar 
will  be  seen  a  slight  ridge  on  the  mucous  membrane.  The  cephalic 
end  of  this  ridge  is  about  1  cm.  from  the  edge  of  the  lip,  and  at  the 
end  will  be  seen  a  slight  circular  depression,  which  is  the  opening 


THE    SALIVARY    GLANDS.  299 

of  the  duct.  Enlarge  the  opening  with  the  probe  of  the  tracer,  and 
insert  a  beaded  bristle  or  a  canula  for  injection.  Inject  as  directed 
for  Wharton^  s  duct  (§  775). 

§  777.  Exposure  of  the  Salivary  Glands  and  their  Ducts. 
— Divide  the  skin  as  follows : — (A)  Along  the  lateral  border  of 
mandibular  ramus  from  the  canine  tooth  directly  caudad  as  far  as 
the  caudal  end  of  the  larynx.  (B)  From  the  candal  end  of  the 
incision  (A)  to  a  point  opposite  the  meatus  auditorius  externus. 
(C)  From  the  maxillary  canine  to  the  dorsal  border  of  the  ear.  (D) 
Along  the  edge  of  the  lips  from  the  mandibular  to  the  maxillary 
canine,  leaving  a  narrow  band  of  skin  with  the  lip. 

Exposure  of  the  Glands,  etc. — Commence  at  the  angle  next  the 
larynx  (ventro-caudal  angle)  and  dissect  the  skin  free.  Use  a  sharp 
scalpel  and  dissect  close  to  the  skin.  Then  commence  at  the  same 
point  and  dissect  free  the  thin  dermal  muscle  (§  608)  in  the  same 
manner  that  the  skin  was  dissected.  It  is  necessary  to  take  the 
greatest  care  in  removing  the  muscle  in  order  to  avoid  injury  to 
nerves  and  vessels.  Remove  the  caudal  part  first,  thus  exposing 
the  glands  and  larger  vessels  and  nerves,  which  are  more  easily  seen, 
than  their  branches.  Compare  the  appearances  presented  with 
those  showm  in  Fig.  67.  If  the  gland  ducts  were  injected  with  fine 
mass,  the  glands  will  be  of  the  same  color  as  the  mass  used.  The 
duct  of  the  parotid  (Fig.  87)  will  be  very  conspicuous  and  wdll  serve 
as  a  kind  of  landmark.  The  same  is  true  of  the  F.  jugularis  (Fig. 
87,  101). 

In  exposing  and  isolating  nerves  and  vessels  in  this  preparation, 
it  is  necessary  to  work  with  the  greatest  care.  The  sharp  tracer 
cannot  be  used  as  safely  as  in  most  cases.  Use  the  dull  tracer,  fine 
forceps  and  scissors,  and  remove  fat  and  connective  tissue  piece- 
meal. So  many  branches  of  the  nerves  enter  the  dermal  muscle 
that  it  is  necessary  to  dissect  it  very  carefully,  so  as  not  to  remove 
at  the  same  time  the  larger  branches  of  the  nerves. 

Explanation  of  Fig.  87.— A.  fac,  A.  facialis. — Facial  artery; 
a  branch  of  the  carotid.  Ductus  Stenon.  (Stenonianus). — Stenon's 
duct ;  duct  of  the  parotid  gland.  Glandula  parotis. — The  parotid 
gland,  the  largest  of  the  salivary  glands.  Gl.  (G-landula)  submax- 
illaris. — The  submaxillary  gland.  Gl.  m.,  Glandula  molaris. — 
Molar  gland.  Mandible. — Inferior  maxilla,  lower  jaw.  M.  civ. 
(clavo-)  trapezius  (Fig.  66).     M.  sterno-mstd.   (mastoideus)  (Fig. 


300  ANATOMICAL    TECHNOLOGY. 

72).  M.  tmp.,  M.  temporalis.  M.  mstr.,  M.  masseter  (Fig.  67). — 
Masseter  muscle.  N.  aur.  (auricularis)  magnus,  N.  tmp.  fac,  N. 
temporo-facialis. — Branches  of  the  temporo-facial  division  of  the 
facial  nerve  (vii).  N.  crv.  facial.,  N.  cervico-facialis.— Cervico- 
facial division  of  i\\Q facial  nerve  (vii).  N.  tmp.  aur.,  N.  temporo- 
auricularis. — Branches  of  the  temporo-auricular  division  of  the 


Fig.  87.— Salivary  Glands  op  the  Left  Side  ;    x  1. 

trigeminus  nerve  (v).  Pili  tactiles.— Tactile  hairs.  There  are 
usually  5-8  of  these.  They  are  supplied  by  branches  of  the  tri- 
geminus nerve  (v)  and  are  supposed  to  be  tactile  hairs.  Vibrissae.— 
Whiskers.  These  stiff  hairs  are  likewise  supplied  by  branches  of 
the  trigeminus  nerve  and  are  also  supposed  to  be  tactile  organs. 
V.  facialis.— Facial  vein.  A  branch  of  the  external  jugular  vein. 
v.  jugularis  externa.— The  external  jugular  vein.     It  almost  inva- 


NERVES    OF    THE    FACE,  301 

riably  lies  between  the  parotid  and  submaxillary  and  separates 
the  latter  from  the  lymphatic  immediately  cephalad  of  it.     Zygoma, 
arcus  zygomaticus. — The  zygomatic  arch  (Fig.  56). 
For  the  manner  of  preparation,  see  §§  772,  777. 

§  778.  Nerves. — Oervico-facial  dims  ton  of  the  facialis  (vii) 
(Fig.  87). — This  emerges  from  the  ental  surface  of  the  lymphatic 
gland  (Fig.  87,  Gl.  lym.),  crosses  the  V.  facialis  and  divides  into  the 
two  main  divisions,  one  of  which  extends  along  the  mandible,  the 
other  dorso-cephalad  toward  the  angle  of  the  mouth. 

Temporofacial  dimsion  of  the  facialis  (vii)  (Fig  87,  N.  tmp. 
fac.).— About  1  cm.  dorsad  of  the  parotid  duct  there  emerges  an- 
other branch  which  extends  dorso-cephalad  and  spreads  out  in 
many  branches  over  the  side  of  the  head  and  face. 

Temporo-auricular  dimsion  of  the  trigeminus  (branch  of  the  3d 
or  inferior  division  of  the  V  nerve). — It  has  the  same  general  direc- 
tion as  the  temporo-facial  branch  of  the  facialis  and  anastomoses 
freely  with  it.  Its  fine  branches  spread  out  over  the  head  and  face 
as  do  those  of  the  temporo-facial. 

At  the  dorso-cephalic  angle  of  the  parotid  emerges  another 
branch  of  the  temporo-auricular  (Fig.  87,  N.  tmp.  aur.).  It  extends 
almost  directly  dorsad. 

Auricularis  magnus  (Fig.  87). — This  large  spinal  nerve  emerges 
from  between  the  MM.  clavo-trapezius  and  sterno-mastoideus.  It 
then  extends  dorso-cephalad  and  spreads  out  over  the  caudal  sur- 
face of  the  external  ear. 

GLANDULE  SALIVARI^. 

§  779.  Glandiila  parotis— Parotid  gland. — The  position  and 
relations  of  this  gland  are  well  shown  in  Fig.  87.  It  surrounds  the 
ventral  half  of  the  external  ear. 

§  780.  Ductus  Stenonianus — Stenon's  duct,  duct  of  the  parotid 
gland  (Fig.  87).— It  extends  cephalad  from  the  cephalic  edge  of  the 
gland  along  the  ectal  surface  of  the  masseter  muscle,  nearly  directly 
toward  the  angle  of  the  mouth.  When  near  the  edge  of  the  lip  it 
penetrates  the  cheek,  passing  en  tad  of  the  facial  vein  (Fig.  87,  V. 
facialis).  It  opens  on  the  mucous  surface  of  the  cheek  opposite  the 
most  prominent  cusp  of  the  last  prsemolar  (Fig.  57). 

Isolate  the  duct  as  directed  for  nerves  and  vessels  (§  777).  It 
may  be  easily  traced  if  it  has  been  injected  or  if  a  black  bristle  has 


802  ANATOMICAL    TECHNOLOGY. 

been  inserted.    Near  the  gland  it  wiil  be  seen  to  divide  into  several 
branches. 

§  781.  Glandula  parotidea  accessoria  —  Accessory  parotid 
gland. — In  about  one  subject  in  ten  there  may  be  found  one  or 
more  small  glandular  masses  connected  with  the  parotid  duct. 
These  are  sometimes  in  contact  with  the  duct  at  some  point  of  its 
course  over  the  masseter,  or  they  may  be  separated  for  a  centimeter 
or  more ;  if  separated,  a  slender  duct  connects  them  with  the  main 
duct.    Mivart,  B,  173. 

§  782.  Glandula  submaxillaris — Submaxillary  gland  (Fig.  87). 
The  submaxillary  gland  is  ventrad  and  partly  entad  of  the  parotid. 
Its  cephalic  edge  is  also  covered  by  two  lymphatics.  The  lobula- 
tions of  the  submaxillary  are  coarser  than  those  of  the  parotid  ;  and 
if  uninjected  it  is  of  deeper  color. 

§  783.  Ductus  Whartonianus — Wharton's  duct,  duct  of  the 
submaxillary  gland. — In  order  to  expose  this,  the  lymphatics  and 
the  vein  should  be  removed.  The  duct  appears  at  the  cephalic  bor- 
der of  the  gland,  and  extends  almost  directly  dorsad,  XDassing  be- 
tween the  MM.  digastricus  (Fig.  101)  and  masseter  (67),  until  it 
reaches  the  floor  of  the  mouth  opposite  the  last  tooth.  In  its  pass- 
age between  the  muscles,  its  lateral  surface  is  crossed  by  the  gusta- 
tory hrancJi  of  the  N.  trigeminus  (v). 

Exposure. — Divide  and  reflect  the  M.  digastricus  (Fig.  101) ; 
then  the  duct  may  be  traced  to  the  floor  of  the  mouth.  Its  passage 
along  the  floor  of  the  mouth  to  the  papilla  may  be  more  readily 
traced  by  removing  part  or  all  of  the  corresponding  mandibular 
ramus. 

§  784.  Glandula  sublingualis — Sublingual  gland.— The  sublin- 
gual gland  in  the  cat  is  quite  small  and  so  closely  connected  to  the 
submaxillary  that  it  appears  as  an  accessory  of  it.  It  is  elongated 
and  extends  cephalad  from  the  submaxillary  about  2  cm.  and  par- 
allel with  Wharton's  duct.  Its  duct,  smaller  than  that  of  the  sub- 
maxillary, extends  parallel  with  it  and  opens  upon  the  same  papilla. 

§  785.  Glandula  molaris — Molar  gland. — This  gland  is  small  as 
compared  with  the  parotid,  but  is  of  the  same  general  appearance. 
It  is  situated  near  the  angle  of  the  mouth  about  1  cm.  ventrad  of 
Stenon's  duct.  It  has  several  ducts  which  pass  straight  through 
the  cheek  and  open  on  the  mucous  surface.  This  gland  is  con- 
sidered by  Cuvier  (A,  III,  424),  Ward,  (A,  lY,  426),  and  Quain 


MOUTH    OR    BUCCAL     CAVITY.  303 

(A,  II,  301),  to  be  merely  an  aggregation  of  buccal  glands ;  see 
§794. 

§  786.  Glandula  zygomatica— Zygomatic,  subzygomatic  or  in- 
fraorbital gland. — This  is  a  compact,  somewhat  elongated  gland 
situated  in  the  lateral  part  of  the  orbit.  Its  ventral  end  rests  on  the 
mucous  membrane  of  the  roof  of  the  mouth  just  caudad  of  the  last 
maxillary  tooth  (true  molar,  see  Fig.  57,  D.  M.),  and  its  duct  opens 
at  the  same  place. 

§  787.  To  demonstrate  this  gland,  the  mouth  may  be  kept  open 
by  a  cork  between  the  teeth  ;  then  the  mucous  membrane  just  caudad 
of  the  last  maxillary  tooth  should  be  cut,  and  the  gland  will  appear. 
Or  the  zygoma,  the  malar  process  of  the  maxilla  and  the  masseter 
muscle  may  be  removed  to  expose  the  lateral  surface  of  the  eye- 
ball. The  gland  will  be  found  at  the  ventro-lateral  surface  of  the 
eye.  To  demonstrate  its  duct,  carefully  tear  away  the  gland  sub- 
stance near  its  ventral  end  with  a  tracer. 

§  788.  Structure  of  Salivary  Glands. — The  odm'ous  structure  of  the  salivary  glands 
is  tliat  of  the  racemose  type,  that  is,  like  a  banch  of  grapes,  the  ducts  representing  the 
stems  and  the  lobules  the  fruit. 

§  789.  Microscopic  Structure. — The  ducts,  except  the  very  smallest,  are  lined  with 
columnar  epithelium  ;  the  smallest  are  lined  with  pavement  epithelium.  Their  mode  of 
termination  "  demands  farther  investigation  "  (Strieker,  A,  800).  The  lobules  are  com- 
posed of  groups  of  spheroidal  cells  surroimded  by  a  continuation  of  the  connective  tissue 
forming  the  interlobular  septa.     Quain,  A,  II,  339. 

CAVUM  ORIS,  MOUTH  OR  BUCCAL  CAVITY,  PHARYNX,   az.    (Fig.  77,  88). 

References.— Quain,  A,  II,  300 ;  Gray,  A,  745  ;  Chauveau,  A,  351  ;  Chauveau  (Flem- 
ing), A,  330  ;  Leyh,  A,  864 ;  Owen,  A,  III,  383  ;  Cuvier,  A,  III,  379  ;  Hyrtl,  A,  241 ;  Ge- 
genbaur  (Lankester),  A,  548 ;  Milne-Edwards,  A,  VI,  11  ;  Gurlt,  A,  336. 

§  790.  The  mouth  camty  or  cavum  oris  is  the  cephalic  division 
of  the  alimentary  canal.  It  is  bounded  cephalad  by  the  lips  and 
caudad  by  the  velum  palati  and  the  cephalic  opening  of  the  pha- 
rynx. It  contains  the  teeth,  gums,  alveolar  margins,  the  jaws,  the 
tongue  and  the  tonsils,  and  into  it  open  the  ducts  of  the  salivary 
and  buccal  glands. 

§  791.   Pilar ynx,  az, — See  description  of  Fig.  88. 

Exposure  and  Dissection — Fig.  88. — With  a  scalpel,  divide  the 
skin  and  soft  parts  upon  both  the  dorsal  and  the  ventral  aspects  of 
the  head  1  cm.  sinistrad  of  the  meson  from  the  snout  to  a  point 
opposite  the  2d  or  3d  cervical  vertebra.  With  the  arthrotome,  sep- 
arate the  mandibular  rami  at  the  symphysis  mentis  and  with  bone 


304  AJVATOMICAL    TECHNOLOGY. 

scissors,  cut  the  left  pier  of  the  os  hyoides  (Pig.  30,  §  224).  Hemisect 
the  tongue  and  the  muscles  along  the  ventral  side,  cutting  about 
1  cm.  to  the  left  of  the  meson  and  entirely  through  to  the  buccal 
cavity.  The  trachea  and  oesophagus  should  be  displaced  to  tlie 
right.  Cover  the  hand  with  a  towel  and  grasp  the  left  side  of  tbe 
head,  and  divide  the  entire  head  with  the  saw,  commencing  at  the 
snout  a  little  sinistrad  of  the  meson  and  making  the  strokes  in  the 
dorso-ventral  rather  than  in  the  caudo-cephalic  direction.  With 
nippers,  remove  the  left  side  of  the  vertebral  arch  of  the  atlas^  axis 
and  the  skull  as  far  as  the  meson. 

§  792.  If  a  permanent  preparation  is  to  be  made,  the  remaining 
half  of  the  mandible  should  be  opened  and  a  cork  put  between  the 
teeth  ;  the  tongue  should  be  drawn  slightly  cephalad  and  held  in 
position  by  a  pin  pushed  through  its  tip  and  into  the  floor  of  the 
mouth.  The  velum  palati  may  be  pinned  out  as  in  the  figure. 
Finally,  the  oesophagus  and  larynx  should  have  one  side  cut  away 
for  a  short  distance  and  the  tubular  portion  distended  by  filling  the 
lumen  with  cotton  ;  the  opening  of  the  Eustachian  tube  should  also 
be  filled  with  cotton. 

Begin  the  hardening  in  about  60  per  cent,  alcohol  (§  286).  After 
the  head  has  thoroughly  hardened,  the  brain  may  be  sliced  away 
to  the  meson,  and  the  onesetJimoideum  and  xomer  removed  to  show 
the  turbinated  bones  and  the  passage  from  the  prj3enaris  to  the  post- 
naris.  The  surface,  especially  of  the  tongue,  may  be  freed  from 
mucous  with  a  soft  nail  brush. 

§  793.  Obvious  Structure  of  the  Cavum  oris  or  Mouth. — The  free  surface  is  usually 
quite  firm  and  smooth,  except  in  certain  places,  as  the  roof  of  the  mouth,  where  there  are 
many  ridges  and  fine  projections. 

§  794.  Microscopic  Structure. — The  free  surface  is  made  up  of  stratified  epithelium  rest- 
ing on  a  rather  abundant  submucous  connective  tissue,  in  which  are  small  so  called  huc^al 
glands  of  the  racemose  type  (§  178),  whose  ducts  open  on  the  free  surface. 

§  795.  Obvious  Structure  of  the  Lingua  or  Tongue. — The  free  surface  on  the  ventral 
side  of  the  tongue  is  smooth  and  soft.  On  the  dorsal  side  it  is  beset  with  numerous  pro- 
jections or  papillae  of  various  forms,  named  in  the  order  of  their  abundance  : — Filiform, 
odontoid,  fungiform,  circumvallate. 

§  796.  Microscopic  Structure. — Into  all  the  papillae  extend  loops  of  blood  vessels. 
The  odontoid  variety  are  covered  by  a  homy  substance.  In  the  walls  of  the  circumvallate 
are  imbedded  the  so  called  taste  buds,  flask-like  in  form  and  composed  of  modified  epithe- 
lium. The  principal  mass  of  the  tongue  consists  of  striped  muscle  and  connective  tissue. 
The  muscles  are  arranged  in  an  intricate  net-work,  the  fibers  sometimes  branching  near 
the  mucous  coat.  The  free  or  mucous  coat  consists  of  stratified  epithelium  with  a  small 
amount  of  submucous  connective  tissue.    See  Strieker,  A,  353  ;  Quain,  A,  II,  327. 


BEMISECTION    OF    THE    HEAD. 


305 


Preparation— Fig.  88— See  p.  303,  exposure  and  dissection — 
Pig.  88. 

Explanation  of  Fig.  88. — Atlas,  az, — The  first  cervical  vertebra. 

Axis,  az. — Tlie  second  cervical  vertebra ;  its  odontoid  process  (Fig.  53)  is  shown  pro- 
jecting cephalad  into  the  ring  of  the  atlas. 

Callosum,  Corpus  callosuni,  az. — The  great  commissure  of  the  hemispheres.  (For  this 
and  the  other  parts  of  the  brain,  see  Fig.  117.) 


*J}a:ctttS  NVAartott, 


Fig.  88.— Hemisection  of  the  Head;    x  1.     Compare  with  Pig.  59  and  ^17  and  with 

Plate  II,  Fig.  4. 


Cn.  (Canalis)  Eustachiana. — The  canal  connecting  the  middle  ear  or  tympanum  with 
tlie  pharynx.     Its  crescentic  opening  into  the  pharynx  is  shown  in  this  figure, 

Cn.  (Canalis)  neuralis,  az. — Neural  or  vertebral  canal. — The  neural  canal  is  repre- 
sented by  the  deeply  shaded  space  in  the  vertebne  in  which  the  myelon  rests.     (The  name 
is  put  upon  the  muscles  dorsad  of  the  roof  of  the  arch  of  the  atlas  and  axis.     Through 
ua  inadvertence  no  dotted  line  is  drawn  from  it  to  the  canal ) 
^k  20 


.306  ANATOJIICAL    TECHNOLOGY. 

Chd.  vc,  Chorda  vocalis. — Vocal  cord. 

Dien.,  Diencephalon. — The  abbreviation  is  written  in  the  space  between  the  two 
thalami  known  as  the  diaccelia  or  "  3d  ventricle." 

Dot.  Stenon.,  Ductus  Stenonianus — Stenon's  duct.  Duct  of  the  parotid  gland  (Fig. 
87,  §  780). — Its  opening  is  hidden  by  the  prominent  cusp  of  the  last  prsemolar,  but  a 
bristle  is  represented  as  coming  from  it. 

Ductus  Whartonianus — Wharton's  duct.  Duct  of  the  submaxillary  gland  (§  783). — 
The  prominent  papilla  at  the  summit  of  which  the  duct  opens  is  shown. 

Dura — Dura  mater. — The  dura  is  represented  in  this  figure  as  a  broad  white  line  just 
entad  of  the  cranium  and  then  prolonged  into  the  neural  canal  as  a  sheath  for  the  myelon. 
It  takes  the  place  of  the  periosteum  in  the  skull,  but  the  neural  canal  is  lined  by  a  special 
periosteum,  so  that  the  dura  in  the  neural  canal  belongs  exclusively  to  the  myelon. 

Epen.,  Epencephalon,  Cerebellum. — See  Fig.  117. 

Epglt.,  Epiglottis.— The  triangular  flap  which  aids  in  the  closure  of  the  glottis  dur- 
ing deglutition. 

Ethtrb.,  Ethmoturbinale— The  ethmoturbinal  bone  (Fig.  59,  §  550). 

Falx,  Falx  cerebri,  az. — The  fold  of  dura  separating  the  olfactory  lobes  and  part  of 
the  mesal  surface  of  the  hemispheres  of  the  right  and  left  sides.  In  this  figure  it  is 
shaded  with  horizontal  lines. 

Fraen.,  Fraenum  linguae. — The  more  or  less  plate-like  cephalic  part  of  the  attachment 
of  the  tongue  to  the  floor  of  the  mouth. 

Hy.,  Hypophysis  cerebri,  az. — Pituitary  body.— See  Chap.  X. 

Inf.,  Infundibulum,  az. — The  ventral  prolongation  of  the  diacoelia  into  the  hypophysis. 

Larynx,  az. — The  specialized  cephalic  part  of  the  trachea,  containing  the  vocal  cords. 

Lingua,  az. — Tongue. 

Meatus  ventralis.— The  ventral  and  more  direct  passage  from  the  praenaris  through 
the  nasal  chamber  to  the  Postnaris  or  opening  into  the  pharynx. 

Mcs.,  Medicommissura. — Middle  commissure  (Fig.  117). 

Mesen.,  Mesencephalon. — Optic  lobes. 

Meten.,  Metencephalon,  o^s.— Medulla  oblongata. 

Mxtrb.,  Maxilloturbinale.— Maxilloturbinal  bone  (Fig.  59). 

Myelon,  «2.— Spinal  cord  (Fig.  104). 

N.  op.,  N.  opticus. — Optic  nerve. 

CEs.,  CEsophagus,  «s.— Gullet  (§  801). 

O.  boc,  O.  basioccipitale,  az.  (Fig.  59). 

O.  bsph.,  O.  basisphenoideum,  az.  (Fig.  59). 

O.  praesph.,  O.  praesphenoideum.  az.  (Fig.  59). 

O.  hyoides  (Fig.  30,  g  224). 

O.  pit.,  O.  palatinum  (Fig.  59). 

O.  mx.,  O.  maxillare  (Fig.  59). 

O.  pmx.,  O.  praemaxillare  (Fig.  56). 

O.  soc,  O.  supraoccipitale,  az.  (Fig.  59). 

O.  ip.,  O.  interparietale,  az.  (Fig.  59). 

O.  parietale  (Fig.  56). 

O.  frontis  (Fig.  56). 

O.  nasale  (Fig.  o6,  59). 

Papillae  filiformes— Filiform  papillge  (§  795)  —These  are  the  fine  projections  from  the 
dorsal  surface  of  the  tongue.  Caudally  they  become  broad  and  ligulate  (1-3  mm.  long), 
while  in  the  middle  of  the  cephalic  part  of  the  dorsal  surface  they  are  modified  into  the 
form  next  described  (Strieker,  A,  356).  j 


TBE    NECK.  307 

Ppl.  (Papillae)  odontoides  (Milne-Edwards,  A,  VI,  104).— These  are  tlie  horny  re- 
curved papillae  on  the  dorsal  aspect  of  the  cat's  tongue  with  which  it  rasps  the  surface  of 
bones.     For  the  other  papillae,  see  Quain,  II,  325. 

Ppl.  fng.,  Papillae  fungiformes — Fungiform  papillae. — These  are  the  bead-like  projec- 
tions on  the  dorsal  surface  of  the  tongue.  They  are  especially  abundant  near  the  middle 
of  its  length. 

Ppl.  crcm.,  Papillae  circumvallatae — Circumvallate  papillae. — These  are  few  in  num- 
ber and  are  situated  on  the  dorsal  surface  of  the  tongue  in  the  locality  indicated  in 
Fig.  88.  They  appear  like  large  fungiform  papillae  with  a  trench  and  a  raised  border 
around  them. 

Pharynx,  az, — The  general  cavity  into  which  open  the  month,  postnares,  Eustachian 
tube,  oesophagus  and  trachea. 

Pili  tactiles— Tactile  hairs  (Fig.  87). 

Praenares — Nostrils. — The  opening  of  the  nasal  chamber  at  the  snout. 

Rhinen.,  Rhinencephalon. — Olfactory  lobes. 

Rugae. — The  transverse  wrinkles  or  folds  in  the  roof  of  the  mouth.  There  are  five  or 
six  of  these,  and  they  are  covered  with  short,  stiff  papillae. 

S.  sph.,  Sinus  sphenoideum. — Sphenoidal  sinus  (Fig.  59). 

Symph.  (Symphysis)  menti,  az, — The  amphlarthrodial  articulation  between  the  two 
sides  of  the  mandible. 

Tnt.,  Tentorium  cerebelli. — The  letters  are  on  the  bony  tentorium  (see  Fig.  59),  but 
this  is  seen  to  be  lined  on  its  ental  surface  by  the  dura.  The  dura  is  as  easily  separable 
from  the  bony  tentorium  as  from  the  other  parts  of  the  skull,  and  the  bony  tentorium  itself 
seems  to  be  a  part  of  the  Os  parietaky  not  an  ossification  of  the  membranous  tentorium  as 
stated  by  Flower,  A,  99  ;  see  Cuvier,  A,  III,  Article  10. 

Trachea,  az. — Windpipe.— The  tube  connecting  the  lungs  with  the  pharynx  (Fig.  77). 

VI.  pit.,  Velum  palati,  az. — The  pendulous  or  caudal  portion  of  the  soft  palate.  It  is 
here  represented  as  lifted  from  the  tongue  so  that  it  extends  nearly  caudad  instead  of 
curving  ventrad  as  in  nature. 

Vibrissae — Whiskers.— See  Fig.  87,  88.     In  Fig.  88  their  free  ends  are  cut  ojff. 

§  797.  CoUum,  a2. — Neck. — This  is  the  constricted  portion  of 
the  trunk  cephalad  of  the  tirst  rib,  i.  e.,  between  the  thorax  and 
head  (Fig.  6). 

§  798.  Exposure. — Make  an  incision  along  the  neck  about  2  cm. 
to  the  right  of  the  ventrimeson  as  far  caudad  as  the  first  rib  ;  then  a 
transverse  incision  just  cephalad  of  the  first  rib  to  a  point  2  cm.  to 
the  left  of  the  ventrimeson ;  dissect  off  the  skin  and  the  muscles 
covering  the  trachea  (Fig.  76). 

§  799.  Trachea,  az. — Windpipe  (Fig.  77). — The  trachea  cannot 
be  mistaken,  as  it  is  the  first  tube  uncovered  by  the  removal  of  the 
skin  and  muscles  on  the  ventral  aspect  of  the  neck. 

Cut  out  a  segment  of  the  trachea  3-4  cm.  long.  It  will  be  seen 
to  be  a  cylindrical  tube  stiffened  by  rings  of  cartilage  which  do 
not  meet  on  the  dorsal  side,  excepting  when  the  trachea  is  con- 


308  ANATOMICAL     TECHNOLOGY. 

tracted.    When  uncontracted,  the  dorsal  side  is  fleshy,  something 
like  the  oesophagus. 

§  800.  Microscopic  Structure  of  the  Trachea. — (A)  Its  ectal  layer  is  of  rather  dense 
connective  tissue.  In  it  are  imbedded  the  incomplete  rings  of  cartilage.  (B)  Entad  of  the 
connective  tissue  layer  and  extending  around  about  the  dorsal  third  of  the  circumference 
of  the  trachea  is  a  layer  of  unstriped  muscle.  This  is  partly  attached  to  the  ectal  surface? 
of  the  rings  of  cartilage,  and  by  its  contraction  causes  the  rings  to  meet  or  even  overlap, 
(C)  Entad  of  (A)  and  (B)  is  a  layer  mostly  composed  of  elastic  connective  tissue.  (D)  Mu- 
cous membrane.  This  lines  the  lumen  of  the  trachea.  It  is  composed  of  three  layers  of 
cells,  the  free  layer  of  which  is  ciliated.  (E)  Imbedded  in  the  wall  of  the  trachea  are 
inany  racemose  glands  whose  ducts  open  on  the  free  surface  of  the  mucous  membrane.  See 
Strieker,  A,  435  ;  Quain,  A,  II,  266. 

§  801.  CEsophagus,  r/2'.— Gullet  (Fig.  77,  109).— Tlie  oesophagus 
is  the  fleshy  tube  connecting  the  pharynx  and  stomach. 

§  802.  Demonstration. — Draw  the  trachea  somewhat  dextrad, 
and  there  will  be  seen  the  oesophagus,  an  entirely  fleshy  tube,  dor- 
sad and  slightly  to  the  left  of  the  trachea.  When  empty  it  does 
not  retain  a  cylindrical  form  like  the  trachea,  but  collapses. 

§  803.  Structure  of  the  (Esophagus. — (A)  The  ectal  layer  is  composed  of  striated  mus- 
cular fibers  arranged  as  in  the  intestine  (§  741),  with  an  admixture  of  unstriated  muscle 
increasing  caudad,  (B)  The  intermediate  layer  is  of  connective  tissue  and  forms  the  sub- 
mucosa.  It  contains  many  small  racemose  glands.  (C)  The  ental  or  mucous  layer  is 
composed  of  stratified  epithelium.     See  Strieker,  A,  361  ;  Qaain,  A,  II,  344. 

THORAX. 

§  804.  The  thorax  or  chest  is  the  part  of  the  trunk  between  the 
diaphragm  and  first  rib.  Its  cavity  contains  the  lungs  (§  809),  the 
heart  and  great  vessels  (Fig.  91),  and  part  of  the  trachea  and 
oesophagus  (§§  799,  801 ;  see  also  Chap.  YIII). 

§  805.  Exposure. — Determine  the  position  of  the  following  land- 
marks :  prcBsiernum  (§  228) ;  xiphisternum  (§  228) ;  first  rib  (Pig. 
30,  72) ;  ventrimeson— the  line  between  the  xiphisternum  and  prse- 
sternum. 

Incisions. — A.  Make  a  longitudinal  incision  (§  599)  through  the 
skin  and  muscles  3  cm.  to  the  right  of  the  ventrimeson  from  the  first, 
rib  to  a  point  opposite  the  base  of  the  xiphisternum.     Taking  care 
not  to  injure  the  vessels  and  nerves  in  the  axillary  region,  reflect 
the  skin  for  2-3  cm.  on  the  right  of  the  incision. 

B.  Make  a  transverse  incision  from  the  caudal  end  of  the  longi- 
tudinal incision  to  a  point  4-5  cm.  to  the  left  of  the  ventrimeson. 


THE    PLEURA.  309 

Reflect  the  skin  across  the  ventrimeson  as  far  as  the  transverse 
incision  extends.  Scrape  or  dissect  the  muscles  from  the  ectal  sur- 
face of  the  ribs  and  cartilages  near  their  union  ;  see  Fig.  50. 

C.  With  the  arthrotome  or  strong  scissors,  cut  through  the  tho- 
racic wall  on  both  sides,  just  mesad  of  the  junction  of  the  cartilages 
and  ribs. 

§  806.  Pleura,  Septum  mediastinale. — Grasp  the  cut  edges  of 
the  right  costicartilages  and  turn  the  sternum  partly  to  the  left  side. 
The  ental  surface  of  the  thoracic  wall  is  covered  by  a  smooth  glis- 
tening membrane,  the  pleura,  a  serous  membrane  like  the  perito- 
neum (§  725) ;  like  the  latter,  it  may  be  detached  over  a  small  space 
by  means  of  the  tracer. 

At  the  meson  will  be  seen  a  transparent  curtain  containing 
blood  vessels  and  more  or  less  fat.  TJiis  is  the  mediastinum,  me- 
diastinal septum  or  septum  thoracis  (Fig.  7,  99,  100).  It  divides 
the  thorax  into  a  right  and  left  half.  Each  half  of  the  thorax  is 
lined  by  a  separate  serous  sac,  and  the  meeting  of  these  on  the 
meson  produces  the  mediastinal  septum.  The  thorax  thus  differs 
markedly  from  the  abdomen,  where  there  is  but  one  serous  sac 
(§  725),  but  the  thoracic  organs,  like  those  of  the  abdomen,  are  all 
properly  ectad  of  or  outside  the  serous  membrane.  Some  of  the 
organs,  as  the  heart,  are  between  the  two  walls  of  the  septum,  while 
others,  as  the  lungs,  are  apparently  within  the  sacs,  as  the  alimen- 
tary canal  is  within  the  peritoneal  sac  (see  Fig.  78). 

§  807.  After  the  mediastinal  septum  has  been  examined,  make, 
with  bone  scissors,  a  transverse  incision  from  the  right  to  the  left 
between  the  incisions  in  the  thoracic  wall,  cutting  the  soft  parts  in 
the  intercostal  space  between  the  9th  and  10th  ribs.  Then  cut  the 
mediastinum  near  its  attachment  to  the  sternum  to  a  point  opposite 
the  4th  costal  cartilage,  avoiding  injury  to  the  blood  vessels. 
Finally,  turn  the  sternum  cephalad  and  secure  it  in  this  position 
with  a  string  or  a  pin. 

With  the  nippei-s,  cut  the  ribs,  excepting  the  first,  on  each  side 
along  a  line  about  3  cm.  from  their  tubercula,  and  with  scissors  or 
a  scalpel,  cut  the  soft  parts  and  remove  the  freed  portion  of  the 
thoracic  wall. 

§  808.  Thymus  gland. — If  the  cat  is  young,  there  will  be  seen 
an  elongated  pinkish  body  (Fig.  77)  extending  along  the  ventral 
side  of  the  trachea  and  great  vessels  from  the  heart  to  a  point  some- 
what cephalad  of  the  first  rib.     This  is  one  of  the  so  called  ductless 


310 


ANATOMICAL    TECHNOLOGY. 


glands  ;  it  is  also  a  temporary  organ  and  may  be  entirely  absent  in 
old  animals.    Its  function  is  not  well  understood. 


References  to  the  Lung^s.— Quain,  A,  II,  389 ;  Gray,  A,  827  ;  Chauveau,  A,  493 ; 
Chauveau  (Fleming),  A,  466 ;  Leyh,  A,  444  ;  Owen,  A,  III,  572  ;  Cuvier,  A,  VII,  19  ; 
Hyrtl,  A,  306  ;  Gegenbaur,  A,  572 ;  Milne-Edwards,  A,  II,  334  ;  Williams  (T.),  A,  V,  258. 


^ 


Glwss  tube. 

Plnck  cocL 
aiisttcibe. 


]Ru.bLeh  stoppet. 
Tkte,adL 


Fig.  89.— Lungs  and  Trachea  ;  x  .2. 
(The  apparatus  is  arranged  as  for  an 
experiment ;  see  Wilder,  33.) 


§  809.  Pulmo  —  Lung  (Fig. 
77,  89,  99,  100).— On  each  side 
of  the  thorax,  extending  from 
the  diaphragm  to  the  first  rib, 
will  be  seen  a  sponge-like  mass. 
Each  of  these  masses  is  a  lung ; 
and  the  two  are  the  essential  or- 
gans of  respiration.  Insert  a 
glass  tube  or  a  flexible  blow-pipe 
into  the  trachea  and  inflate  the 
lung.  The  trachea  must  be 
pressed  closely  against  the  tube 
to  prevent  the  escape  of  air. 

§  810.  Lohes,—E2iQh  half  of 
the  inflated  lung  will  be  seen  to 
consist  of  several  divisions,  the  so 
called  lohes.  There  are  three  on 
each  side — cepJialic,  intermediate 
or  middle,  and  caudal  (Fig.  89). 

Azygous  Lohe.  —  The  right 
lung,  in  addition  to  the  three 
lobes  mentioned  in  the  preceding 
paragraph,  has  a  small  one,  the 
azygous  lohe,  projecting  into  a 
kind  of  pocket  formed  of  pleura, 
dorso-caudad  of  the  apex  of  the 
heart  and  between  it  and  the  dia- 
phragm (Fig.  77,  103,  C.  1.,  az.). 
The  free  edge  of  this  pocket  is 
This  lobe  is  sometimes  deeply  divided 


bounded  by  the  postcava 

into  two,  the  caudal  of  which  is  the  larger. 

§  811.  Alveoli. — Hold  an  edge  of  the  inflated  lung  between  the 
eye  and  the  light,  and  note  that  it  is  divided  into  spaces  about  1  mm. 
in  diameter.     These  are  the  air  sacs  or  alveoli  (§  813,  814). 

/ 


THE    DIAPHRAGM.  311 

§  812.  Bronchi  and  Bronchioli.— The  tracliea  should  be  fol- 
lowed from  the  neck  into  the  thorax,  cutting  or  tearing  away  any 
blood  vessels  or  nerves  that  cover  its  ventral  surface,  and  also  the 
thymus  (Fig.  77,  §  808).  Near  the  intermediate  lobe  of  the  lung, 
the  trachea  divides  into  the  two  bronchial  tubes ^  one  of  which  goes 
to  each  lung.  Tear  away  the  substance  of  the  lung  sufficiently  to 
foUow  one  bronchus.  It  will  be  seen  to  continually  divide  and  so 
form  the  bronchioli. 

%  813.  Obvious  Structure  of  a  Lung. — On  entering:  the  lung  tlie  bronchus  divides  like 
a  tree  into  branches  ipronchioli).  Near  their  termination  the  bronchioli  dilate  somewhat, 
thus  forming  the  so  called  infundihula  or  ultimate  lobules.  From  the  wall  of  the  infun- 
dibulum  project  sac -like  recesses  singly  or  in  groups.  Each  recess  is  called  an  alveolus, 
and  may  be  considered  as  the  blind  ampulliform  termination  of  the  smallest  division  of  an 
air  tube.  The  alveoli  may  be  readily  seen  by  looking  at  the  edge  of  an  inflated  lung  as 
directed  above  (§  811). 

§  814.  Microscopic  Structure. — This  is  very  complicated,  its  main  features  being  as  fol- 
lows : — (A)  The  air  tubes  are  composed  of  an  ectal  dense,  largely  elastic,  connective  tissue 
layer,  in  which  are  found  plates  of  cartilage.  (B)  Unstriated  muscular  layer.  (C)  An 
clastic  connectim  tissue  layer.    (D)  The  mucous  membrane  with  its  ciliated  epithelium. 

In  the  smallest  air  tubes  the  cartilage  disappears.  In  the  larger  ones  are  small  race- 
mose glands  as  in  the  trachea.  As  an  air  tube  enters  a  lobule,  its  ciliated  epithelium  is 
supplanted  by  a  stratum  of  cubical,  non-ciliated  cells.  The  unstriped  muscle  also  disap- 
pears, and  finally  the  alveoli  are  lined  with  a  single  layer  of  pavement  or  scaly  epithelium. 
See  Strieker.  A,  437 ;  Quain,  A,  II,  278. 

DIAPHRAGMA,  as.— DIAPHRAGM. 

References.— Straus-Durckheim,  A,  II,  309  ;  Quain,  A,  I,  308 ;  Gray,  A,  394  ;  Milne- 
Edwards,  II,  406  ;  Chauveau  (Fleming),  A,  245 ;  Chauveau,  A,  260  ;  Gegenbaur  (Lankes- 
ter),  A,  574 ;  Hyrtl,  A,  316  ;  Cuvier,  A,  VII,  198  ;  Owen,  A,  III,  1. 

§  815.  The  Diaphragm  (Fig.  77,  90)  is  a  musculo-tendinous  cur- 
tain completely  separating  the  thoracic  and  abdominal  cavities. 
Many  structures  transverse  it,  but  they  are  joined  to  their  respective 
apertures  in  such  a  manner  that  the  partition  is  absolutely  air-tight, 
and  yet  no  hindrance  is  put  upon  the  free  movement  of  the  dia- 
phragm in  respiration. 

Tiie  tendinous  part  (Fig.  90)  is  near  the  middle.  Its  form  is 
somewhat  crescent  shaped,  the  horns  of  the  crescent  pointing  dor- 
sad. From  the  tendon  radiate  the  muscular  fibers.  Those  of  the 
dorso-mesal  third  converge  and  form  two  thickened  masses  called 
the  crura  or  pillars  of  the  diaphragm. 

The  diaphragm  is  attached  to  the  xiphisternum^  to  the  last  fixe 
ribs,  and  somewhat  loosely  to  the  thick  muscles  which  lie  ventrad 
of  the  vertebrae.     The  crura  unite,  forming  a  single  dense  tendon, 


312  ANATOMICAL     TECHNOLOGY. 

which  is  attached  to  the  centra  of  the  M^  3d  and  U^  lumbar  xer- 
tebrcB. 

It  will  be  seen  from  the  above  that  the  diaphragm  is  attached 
very  obliquely  to  the  body  wall  so  that  the  dorsal  part  is  caudad 
of  the  ventral.  The  central  part  is  strongly  arched  into  the  thoracic 
cavity. 

§  816.  Posture  and  Preparation.— The  cat  should  be  placed  in 
a  dorsicumbent  posture,  the  abdomen  opened  as  directed  for  the 
study  of  the  viscera  <;§§  287,  710),  and  injected  from  the  abdominal 
aorta  and  postcava  (§§  363,  365).  The  abdominal  wall  should  be 
cut  along  a  line  about  2  cm.  caudad  of  the  diaphragm.  The  liver 
and  stomach  should  be  drawn  somewhat  caudad  ;  the  suspensory 
ligament^  the  postcava  and  the  oesophagus  cut,  the  two  last  named 
about  2  cm.  from  the  diaphragm.  Care  should  be  taken  not  to 
cut  the  diaphragm  in  any  of  the  operations. 

The  kidneys  (Fig.  101)  should  be  removed,  and  the  aorta  about 
2  cm.  caudad  of  the  origin  of  the  superior  mesentery  artery.  The 
vertebral  column  should  be  disarticulated  between  the  4th  and  5th 
lumbar  vertebrse  (Fig.  30).  The  superior  mesenteric  artery  and  the 
cceliac  artery  and  the  splanchnic  nerve  (Fig.  103,  107,  A.  c,  N. 
splnch.),  should  be  carefully  isolated  with  the  tracer,  line  forceps 
and  fine  scissors.  It  is  also  desirable  to  isolate  the  vagus  (gastric 
nerves)  on  the  oesophagus  (see  Fig.  103,  107,  N.  g.  d.  N.  g.  v.).  The 
ribs  should  be  cut  near  their  tubercula,  and  then  the  ventral  border 
of  the  diaphragm  drawn  strongly  cephalad  and  held  in  position  with 
large  pins.  Lastly,  the  fat  and  connective  tissue  should  be  removed 
from  the  muscles  so  as  to  show  the  direction  of  the  diaphragmatic 
fibers  and  their  interdigitations  with  those  of  the  M.  transfer  salts. 

Preparation— Fig.  90.— The  thoracic  duct  (Fig.  103),  the  abdom- 
inal aorta  Sindi  postcava  (Fig.  101)  were  injected.  The  cat  was  then 
transected,  following  a  line  about  1  cm.  caudad  of  the  tip  of  the 
xiphi sternum  and  going  between  the  4th  and  5tli  lumbar  vertebrae. 
The  ventral  border  of  the  diaphragm  was  drawn  strongly  cephalad 
and  cotton  placed  on  the  pleural  side  to  make  it  nearly  level. 

Explanation  of  Fig.  90. — Aorta,  az. 

A.  phrn.,  A.  phrenica. — The  phrenic  or  diapliragmatic  artery. 

A.  adrn.  Imb.,  A.  adreno-lumbalis.— The  adreno-lumbar  artery,  a  small  artery  aris- 
inpr  from  the  aorta  and  supplying  the  adrenal  body  and  the  cephalic  part  of  the  lumbar 
rejyion. 

C,  A.  coeliaca,  az. — The  cceliac  artery  or  coeliac  axis. 


THE    DIAPHRAGM.  313 

Crus  dphrg.,  Crus  diaphragmatica. — The  left  cms  or  pillar  of  the  diaphragm. 
Dct.  thr.,  Ductus  thoracicus,  as.— The  left  thoracic  duct  (Fig.  103). 
Gng.  (Ganglion)  semilunare. — The  semilunar  ganglion — Ganglion  of  the  solar  plexus 
of  nerves  (Fig.  107). 

M.,  A.  mesenterica  superior,  az.  (Fig.  103,  107). 


Fig.  90. — Caudal  View  of  the  Diaphragm  with  the  Structures  that  traverse 

IT  ;     X  .75. 

Mb.,  Membrana. — The  somewhat  crescent-shaped  membranes  which,  with  the  mus- 
cular portion  of  the  diaphragm,  complete  it  dorsad.  It  is  said  by  Straus-Durckheim 
A,  IT,  310,  that,  in  place  of  these  membranes,  there  are  often  muscular  pillars — lateral 
pillars  of  the  diaphragm — ^joining  the  diapophyses  of  the  2d  lumbar  vertebrae. 

M.  transversalis-abdominis. 

M.  q.  lumb.,  M.  quadratus  lumborum. 

M.  psoas.     (The  human  psoas  magnus.) 


314  ANATOMICAL    TECHNOLOGY. 

NN.  sym.,  NN,  sympathici. — The  sympathic  nerves  of  tlie  two  sides  continued  into 
the  abdomen. 

NN.  splnch.,  NN.  splanchnici.— The  two  splanchnic  nerves  of  each  side  joining  the 
corresponding  semilunar  ganglion  (Fig.  107,  Gng.  smln.), 

N.  gastricus — Gastric  nerve. — There  are  two  of  these,  one  on  the  dorsal  and  one  on 
the  ventral  side  of  the  oesophagus  (Fig-.  107,  N.  gstr.  dor.,  N,  gstr.  vnt.).  They  are  the 
continuations  of  the  vagus  nerves  into  the  abdomen. 

CEs.,  (Esophagus,  az. — This  is  somewhat  loosely  attached  to  the  diaphragm,  and 
hence  can  move  longitudinally  quite  freely  (Fig-.  107,  (Es.). 

Pcv.,  Postcava,  az. — The  great  vein  returning  blood  to  the  heart  from  the  caudal 
half  of  the  body  (Fig.  101). 

Tendo  centralis,  az. — The  central  tendon  of  the  diaphragm. 

Tendo,  az. — The  common  tendon  of  the  two  crura  of  the  diaphragm.  It  is  very 
strong  and  firmly  attached  to  the  2d,  3d  and  4th  lumbar  vertebrae. 

VV.  phrn.,  Venae  phrenicae. — The  phrenic  veins.  The  large  trunks  follow  mostly 
the  two  horns  of  the  tendo  centralis. 

VV.  hepat..  Venae  hepaticae,  az. — Two  hepatic  veins  from  the  right  lobe  of  th«i  liver. 
They  unite  just  as  they  enter  the  vena  cava  (Fig.  101). 

Xiphisternum,  az. 


CHAPTEK    VIII. 

THE    VASCULAR    SYSTEM. 

GENERAL   CONSIDERATIONS  —  HEART — ARTERIES  —CAPILLARIES — VEINS  —  LYMPHATICS — 

THORACIC   DUCTS. 

§  817.  General  Considerations.— In  the  cat,  as  in  man  and  the 
higher  animals  generally,  the  tissues  are  supplied  with  blood,  and 
blood  and  lymph  are  removed  from  the  tissues,  by  means  of  a  series 
of  closed  tubes  or  vessels.  These  tubes  all  communicate  more  or 
less  directly  with  one  another,  but — excepting  the  lymphatic  siom- 
ita — present  no  obvious  openings  into  any  other  parts.  This  closed 
jries  of  tubes  is  known  as  the  vascular  system. 

The  vascular  system  as  a  whole  consists  of  two  main  divisions, — 

I  blood  vascular  system  and  the  lymph  vascular  system  or 

iphatic  system. 

818.  The  blood  vascular  system  is  that  by  which  the  blood  is  (A)  conveyed  to  the 
Hssues  in  general  for  their  nourishment  and  returned  therefrom ;  (B)  conveyed  to  the 
lungs  for  its  own  improvement  and  returned  therefrom  (Fig,  92).  Those  parts  which  are 
concerned  in  the  transfer  to  and  from  the  lungs  constitute  the  pulmonic  division  of  the 
blood  vascular  system,  and  the  remainder  constitute  the  general  or  systemic  division. 
While  in  process  of  transfer,  the  blood  is  said  to  perform  either  the  pulmonic  or  the 
systemic  circulation. 

§  819.  Subdicisions  of  the  Blood  Vascular  Si/stem. — There  are  four  parts,  continuous 
with  each  other,  but  more  or  less  distinctly  differentiated  :  (A)  A  central  receiving  and 
distributing-  organ,  tlie  heart  (cardia)  ;  (B)  tubes  extending  from  the  heart  throughout  the 
lungs  and  the  organs  generally,  the  arteries ;  these  divide  and  diminish  in  size  like  the 
branches  of  a  tree,  and  gradually  merge  into  (C)  the  capillaries,  the  most  minute  vessels, 
which  in  turn  unite  and  gradually  merge  into  (D)  the  veins,  which  unite  and  increase  in 
size  as  they  diminish  in  number  and  finally  tenninate  in  the  heart  (Fig.  92). 

The  arteries  are  said  to  continually  divide  and  decrease  in  size  because  the  current 
therein  is  from  the  larger  vessels  toward  the  smaller.  The  veins  are  said  to  unite  and 
increase  in  size  because  the  blood  current  is  from  the  smaller  to  the  larger  branches. 
Again,  the  arteries  are  said  to  extend  from  the  heart  peripherad,  that  is,  in  the  direction  of 
their  blood  current,  while  the  veins  are  said  to  extend  toward  the  heart  or  centrad,  as  the 
current  is  toward  the  central  organ.  The  veins  differ  from  the  arteries  by  having  thinner 
walls  and  by  the  presence  of  valves  in  many  (Fig.  102,  B,  C). 


316  ANATOMICAL    TECHNOLOGY. 

§  820.  The  Lymph  Vascular  System. — This  is  that  part  of  the  general  vascular  sys- 
tem which  collects  the  lymph  from  the  tissues  and  the  chyle  from  the  alimentary  canal 
and  conveys  them  to  the  great  veins  ;  it  is  thus  an  auxiliary  of  the  venous  system  (Bernard, 
A,  250).  From  the  office  of  collecting  both  lymph  and  chyle,  it  is  commonly  considered 
as  forming  two  divisions  :  (A)  The  lymphatics  proper  ;  (B)  the  lacteals  or  chyle  vessels. 

§  821.  The  lymphatic  system  is  somewhat  comparable  to  the  venous,  since  its  vessels 
begin  as  capillaries  at  the  periphery  and  extend  toward  the  center.  Like  the  veins  also,  the 
lymphatic  vessels  contain  numerous  vahes  which  prevent  a  reversal  of  the  current,  that  is, 
a  flow  from  the  center  toward  the  periphery. 

The  lymphatic  vessels  differ  from  the  veins  in  the  following  particulars :  (A)  They 
have  thinner  walls  ;  (B)  they  do  not  so  markedly  increase  in  size  as  the  veins,  although 
they  anastomose  more  frequently ;  (C)  at  various  points  along  their  course  there  are 
enlargements,  the  so  called  lymphatic  glands,  through  which  the  lymph  passes;  (D)  in- 
stead of  joining  the  central  organ  of  the  vascular  system  directly  as  do  the  blood  vessels, 
the  lymphatic  trunks  open  into  veins  (Fig.  103) ;  (E)  the  lymphatic  system  differs  from 
the  venous  also  in  having  no  direct  communication  through  capillaries  with  anytliing  like 
an  arterial  system  ;  (F)  the  lymphatics  are  found  to  communicate  with  serous  cavities 
through  minute  orifices,  the  stomata  (Quain,  A,  II,  188  ;  Strieker,  A,  222). 

CARDIA~THE  HEART.  , 

§  823.  References.— Quain,  A,  II,  242  ;  Gray,  A.  801  ;  Cuvier,  A,  VI,  272  ;  Gegeubaur 
(Lankester),  A,  583  ;  Hyrtl,  A,  300  ;  Bernard,  A,  274  ;  Milne-Edwards,  A,  III,  473  ;  Owen, 
A,  III,  516  ;  Chauveau,  A,  529  ;  Chauveau  (Fleming),  A,  499  ;  Gurlt,  A,  574 ;  Straus- 
Durckheira,  B,  II,  181  ;  Foster  and  Langley,  A,  91  ;  Smith,  E.  N.,  A,  PI.  47,  48,  49,  55,  56 ; 
Bourgery  and  Jacob,  A,  PI.  9,  Us,  PI.  13  ;  Rolleston,  B,  25-34  ;  McAlpine,  B,  I,  PI.  23; 
Krause,  A,  178,  Fig.  13;  Turner,  A,  899  ;  Sabatier,  A  ;  Flower,  A;  Pettigrew%  64;  Peiti- 
grew,  A  ;  Parchappe,  A  ;  Mojsisovics,  A,  54 ;  Leyh,  A,  559 ;  Mivart,  B,  199-208. 

Remark. — Most  of  the  above  refer  to  the  human  heart  more  especially,  but  the  heart 
of  the  horse  is  chiefly  described  by  Leyh,  Chauveau  and  Gurlt,  and  that  of  the  rabbit  by 
Krause,  McAlpine  and  Foster  and  Langley.  Methods  of  preparation  are  given  by  Hyrtl, 
Straus-Durckheim,  Mojsisovics  and  Pettigrew.  The  only  descriptions  and  figures  purport- 
ing to  refer  to  the  heart  of  the  cat  are  given  by  Mivart ;  unfortunately,  however,  in  Fig. 
102,  the  relative  thickness  of  the  right  and  left  ventricles  is  made  the  reverse  of  what  it 
should  be  (a  probable  oversight  which,  although  readily  corrected  by  the  anatomist,  is 
sure  to  confuse  the  beginner) ;  while  the  usefulness  of  the  text  is  diminished  both  by  the 
general  uncertainty  as  to  how  much  refers  directly  to  the  cat  (§  127),  and  by  the  presence 
of  an  absolute  misstatement  upon  pp.  201,  214  respecting  the  number  of  pulmonary  veins. 

§  823.  Before  dissecting  tlie  heart,  or  even  removing  it  from  the  body,  the  student  will 
do  well  to  familiarize  himself  with  its  general  features  and  location  as  shown  in  Fig.  77, 
91,  101. 

If  he  has  been  following  the  present  work  in  order,  he  will  have  at  least  one  cephalic 
region  of  a  cat  preserved  in  alcohol,  and  may  run  the  risk  of  injuring  the  heart  thereof  in 
removing  it  before  gaining  any  detailed  knowledge  of  it.  He  must  bear  in  mind,  how- 
ever, that  all  the  cavities  of  such  a  heart  will  be  collapsed  and  that  the  auricles  especially 
will  look  very  unlike  the  preparation  shown  in  Fig.  91 .  Such  a  heart  may  serve  for  the 
examination  of  some  parts,  but  eventually  he  should  have  at  least  two  specimens  well  dis- 
tended and  hardened  by  alcohol,  and  if  possible  another  filled  with  plaster, 

§  824.  Preparation— Fig.  ^l.—Th^postcava  and  abdominal  aorta 


THE    HEART. 


317 


were  injected  witli  red  and  blue  plaster  respectively.  After  the  plas- 
ter liad  hardened,  a  small  hole  was  made  in  the  left  ventricle  and  a 
long  canula  inserted  and  pushed  through  the  auriculo-mntricular 
opening  into  the  left  auricle.  Red  plaster  was  then  injected  so  as 
to  fill  the  pulmonary  veins.  Finally,  the  pericardium  was  removed 
together  with  the  fat  and  connective  tissue  covering  the  cardiac 
vessels. 


§  825.  Description. — This,  the  dorsal  or  "  posterior  "  aspect  of  the  heart,  is  less  famil- 
iar to  most  persons  and  leas  frequently  represented.  It  is,  however,  much  more  compre- 
hensive and  instructive  than  the  ventral  aspect, 
and  is  given  in  the  following  works  :  Quain,  A, 
II,  Fig.  168 ;  Smith,  E.  N.,  A,  PL  55  ;  McAl- 
pine,  B,  PI.  XXIII,  Fig.  3  (rabbit) ;  Gegenbaur 
(Lankestar),  A,  Fig.  336  (pig).    . 

The  present  figure  fairly  represents  the  size 
of  a  somewhat  large  heart,  and  its  form  when 
injected.  As  stated,  however,  in  §  829,  it  is 
probable  that  the  less  thickness  of  the  lateral 
wall  of  the  right  ventricle  has  permitted  it  to 
yield  to  the  force  of  the  injection  so  that  the 
right  side  is  unduly  convex. 

The  word  mntriculi  is  written  across  the 
apex  of  the  ventricular  portion,  and  the  abbre- 
viation V.  crd.  is  just  below  the  furrow  between 
that  and  the  auricular  portion. 

For  the  sake  of  showing  certain  parts  more 
distinctly^ the  figure  represents  the  organ  as  if 
rotated  slightly  upon  its  longer  axis  so  as  to  ex- 
pose more  of  the  right  than  of  the  left  side. 
The  line  of  demarcation  between  the  right  and 
left  auricles  {Aur.  dxt.,  Aur.  sin.)  coincides 
nearly  with  a  line  connecting  the  V.  of  V.  crd. 
with  the  left  border  of  the  proBcava.  The  ductus 
arteriosus  (§  867)  is  not  shown. 

§  828.  General  Description  of  the  Heart.— 

The  heart  is  a  hollow,  quadrilocular  (four  cham- 
bered) muscular  organ  situated  in  the  thorax. 
It  is  the  anatomical  and  physiological  center  of 
the  vascular  system,  simultaneously  receiving 

from  the  lungs  and  from  all  other  parts  of  the  body,-  and  distributing  it  thereto. 
§  827.   Location. — As  seen  in  Fig.  77,  99,  101,  the  heart  is  on  the  meson,  but  extends 
a  little  farther  to  the  left  than  to  the  right.     In  Fig.  101  it  appears  at  a  considerable  dis- 
tance from  the  diaphragm,  but  of  the  latter  only  the  dorsal  portion  remains,  and  its 
cephalic  convexity  is  really  very  close  to  or  in  contact  with  the  heart, 
^^b  §  828.   Pericardium. — The  heart  proper  is  enveloped  in  a  fibro-membranous  sac,  the 
^^mricardium,  whicb  is  attached  about  the  roots  of  the  great  vessels,  but  elsewhere  is  uncon- 


Fig.  91. — The  Doksal  Aspect  of  the 
Heakt  with  the  Central  Por- 
tions OP  the  Larger  Vessels; 
from  a  Maltese  cat ;    x  1. 


^tne  VI 
^^od 


318  ANATOMICAL    TECHNOLOGY. 

by  girdling  it  at  about  tbe  middle  of  the  length  of  the  organ  and  reflecting  the  attached 
end  over  the  great  vessels  so  as  to  display  the  line  of  attachment.  Its  relations  to  both 
the  heart  and  the  diaphragm  will  be  mentioned  in  the  descriptions  of  Fig.  99,  100. 

§  829.  Form. — When  moderately  distended,  the  heart  is  approximately  oval  in  shape, 
one  end  obtuse  and  the  other  pointed. 

As  seen  in  Fig.  93,  however,  this  oval  is  not  regular,  one  side  being  more  curved  than 
the  other.  This  is  due  to  the  greater  yielding  of  the  thinner  wall  of  the  right  ventricle 
to  the  pressure  of  the  injection.  As  a  whole  also,  the  organ  is  slightly  flattened  in  what 
will  be  found  to  be  the  dorso-ventral  direction  ;  this  may  be  due  to  the  greater  resistance 
offered  by  the  septum  ventricular e  to  the  pressure  of  the  injection. 

§  830.  Normal  Position.— ^2Li\i.rBX\y,  the  longer  axis  of  the  heart  is  oblique  with 
respect  to  the  meson.  The  smaller  end  points  caudo-sinistro-ventrad.  For  purposes  of 
description,  however,  it  will  be  more  convenient  to  assume  that  the  two  ends  of  the  organ 
point  respectively  cephalad  and  caudad. 

The  obliquity  in  position  of  the  cat's  heart  is  probably  less  than  that  of  man  (as  re- 
marked by  Owen,  A,  III,  525),  but  it  is  nevertheless  decided.  In  frozen  section  No.  11  of 
the  series  from  which  Fig.  99  and  100  were  made,  the  apex  of  the  heart  is  at  least  15  mm. 
sinistrad  of  the  meson. 

§  831.  Size. — Fig.  91  represents  the  natural  size  of  the  preparation  from  which  it  was 
made,  but  the  heart  was  from  a  large  cat,  and  was  somewhat  distended  with  plaster  by 
injection.  In  round  numbers,  the  heart  of  an  average  adult  cat  measures  about  5  cm. 
from  the  apex  to  the  attachment  of  the  prcecava  and  about  3  cm.  across  the  greatest  width 
of  the  ventricular  portion.  We  have  not  yet  ascertained  the  average  weight  of  the  organ, 
but  it  is  very  considerable  in  comparison  with  the  size  and  weight  of  the  animal. 

§  832.  Designation  of  the  Regions. — As  shown  in  Fig.  92,  93,  the  cephalic  and  caudal 
ends  of  the  heart  diflfer  not  only  in  shape,  but  in  the  thickness  of  the  muscular  walls. 
Since  the  two  cavities  enclosed  by  the  thinner  cephalic  walls  are  known  as  auricles,  the 
cephalic  or  basal  region  or  end  of  the  organ  is  spoken  of  as  auricular  ;  in  like  manner,  the 
other  end  or  region  is  called  ventricular  from  the  name  of  the  two  cavities  enclosed  by  the 
thicker  walls. 

As  seen  in  Fig.  95,  96,  there  is  a  partition  between  the  auricles  and  another  between 
the  ventricles.  These  septa  divide  the  organ  into  two  sides  or  portions  like  the  sides  of  a 
double  house.  Since  the  planes  of  the  septa  are  approximately  dorso-ventral,  it  is  custom- 
ary to  speak  of  the  two  sides  as  right  and  left.  The  other  two  surfaces  and  regions  are 
then  respectively  dorsal  and  ventral. 

^  833.  Recognition  of  the  Regions. — The  cephalic  and  caudal  regions  are  readily  distin- 
guished both  from  the  greater  size  of  the  former,  from  the  more  compressible  nature  of 
the  walls,  and  from  the  presence  of  the  vessels  which  enter  or  leave  the  organ.  In  the 
natural  attitude  of  man,  the  base  of  the  heart  is  uppermost,  but  this  somewhat  puzzling 
feature  does  not  appear  when  the  animal  is  regarded  as  in  the  normal  position  of  a  verte- 
■brate(§35). 

The  ventral  aspect  of  the  heart  is  comparatively  regular,  the  two  auricular  appendices 
(Fig.  95)  projecting  slightly  at  the  sides  of  the  two  great  arteries,  aor^«  and^.  pulmonalis. 
The  dorsal  aspect,  on  the  contrary,  is  quite  irregular  in  the  auricular  portion  on  account 
of  the  branching  of  the  two  arteries  just  named,  and  the  entry  of  veins  into  the  auricles 
(Fig.  91). 

The  right  and  left  sides  are  of  course  determined  by  the  determination  of  the  ends  and 
the  other  two  sides.  In  addition,  the  wall  of  the  right  ventricle  is  decidedly  thinner  than 
that  of  the  left,  and  that  region  is  therefore  the  more  compressible. 


REMOVAL    OF    THE    HEART.  319 

§  834.  Removal  of  the  Heart. — ^For  obvious  reasons,  a  cat's 
heart  intended  for  careful  examination  should  be  taken  from  a 
large  adult.  In  most  cases  the  same  cat  may  be  employed  for  the 
removal  of  the  brain  and  for  the  separate  study  of  the  abdominal 
viscera  (Chap.  VII).  Unless  the  vessels  are  to  be  filled  with  plas- 
ter, it  is  better  not  to  bleed  the  animal,  since  the  presence  of  the 
blood  in  the  large  veins  near  the  heart  facilitates  their  recognition. 

Instruments  and  Materials. — Artlirotome  ;  tracer  ;  medium  scalpel ;  coarse  scissors ; 
bone  scissors  ;  nippers  ;  coarse  and  fine  forceps ;  6  pieces  of  linen  thread  about  20  cm.  long  ; 
2  pieces  of  thick  muslin  or  flannel  or  chamois  leather,  each  about  15  x  7  cm.  ;  basin  of 
water  and  towel  ;  large  tray,  with  cords  for  securing  the  legs  of  the  cat. 

Landmarks. — Prsesternum,  xiphisternum  and  epigastrium  (§  228,  Fig.  30,  49,  72,  76)  ; 
clavicle  (§  230,  Fig.  30,  72).  Observe  also  the  general  location  of  the  thoracic  viscera  in 
Fig.  77  and  101  and  the  operations  for  their  exposure  (§§  710,  805). 

§  835.  Exposure.— DiYid^Q  the  skin  (§  599)  as  directed  for  the 
exposure  of  the  thoracic  viscera  (§  805),  but — unless  the  lungs  are 
to  be  employed  for  study  or  experiment — begin  the  longitudinal 
incision  (Fig.  76)  dextrad  of  the  prcesternum  instead  of  the  larynx. 
It  is  also  more  convenient  to  make  a  second  transverse  incision  from 
the  cephalic  end  of  the  longitudinal  one  to  or  beyond  the  corre- 
sponding point  upon  the  left  side. 

The  triangular  or  quadrangular  area  of  skin  so  indicated  is  to  be 
raised  as  directed  in  §  600  and  reflected  sinistrad.  Divide  the  pec- 
toral muscles  (Fig.  72)  on  the  right  by  a  longitudinal  incision  par- 
allel with  the  edge  of  the  skin,  taking  care  not  to  cut  upon  the 
clavicle.  Grasp  the  pectoral  mass  and  dissect  it  up  from  the  proper 
thoracic  wall  to  the  meson.  Repeat  the  operation  upon  the  other 
side  and  then  remove  both  masses  from  their  attachments  to  the 
sternum.  Divide  eacli  M.  rectus  thoracis  (Fig.  72,  73)  at  the  caudal 
transverse  cut  edge  of  skin  and  dissect  them  up  cephalad. 

Through  the  MM.  intercostales  on  each  side  near  the  middle  of 
the  exposed  area,  push  the  conjoined  tips  of  the  coarse  forceps,  and 
forcibly  separate  the  blades  for  about  2  mm.  This  will  permit  air 
to  enter  the  thorax,  and  the  lungs  will  collapse  so  as  to  be  in  less 
danger  of  injury  during  the  subsequent  operation. 

With  the  artlirotome  or  bone  scissors,  divide  the  exposed  costi- 
cartilages  close  to  their  junctions  with  the  ribs.  Cut  across  the 
sternum  just  cephalad  of  the  xiphisternum,  sever  the  septum  medi- 
astinale  and  other  adhesions  to  the  ental  surface  of  the  sternum, 
and  reflect  it  cephalad  with  the  costicartilages  or  remove  it  alto- 
gether. 


320  A  NA  TOMICA  L     TECHXOL  OGY. 

Push  the  lungs  on  both  sides  toward  the  dorsal  part  of  the  cav- 
ity and  with  the  bone  scissors,  or  nippers  and  bone  scissors,  remove 
the  sternal  ends  of  all  the  exposed  ribs  for  2-3  cm.,  so  as  to  facili- 
tate access  to  the  viscera. 

§  836.  Removal. — Lift  the  heart  slightly  by  the  pericardium  and 
sever  its  pleural  attachments  to  the  diaphragm  as  far  dorsad  as  the 
postcava  (Fig.  101).  Put  two  ligatures  upon  the  postcava,  the  cau- 
dal one  about  2  cm.  from  the  diaphragm  if  the  abdominal  vessels 
are  to  be  injected.  In  passing  the  ligatures  about  the  vessel  with 
the  fine  forceps,  avoid  injuring  the  azygous  lobe  of  the  left  lung. 
This  ligature  should  not  be  tied  very  hard. 

Double  ligature  (Fig.  41)  the  prcecava  near  its  bifurcation,  and 
divide  this  and  the  postcava  between  the  two  ligatures. 

If  the  lungs  are  to  be  studied  or  experimented  upon,  place  the 
cloth  or  chamois  over  the  cut  edges  of  the  thoracic  parietes  so  as  to 
protect  the  lungs  from  laceration  by  the  sharp  ends  of  the  ribs. 

Grasp  the  apex  of  the  heart  and  draw  it  ventro-cephalad.  This 
will  expose  the  caudal  and  azygous  lobes  of  the  lungs  (see  Fig.  89), 
the  thoracic  aorta  and  oesophagus.  Insert  the  fingers  dorsad  of  the 
lungs,  lift  them  and  sever  their  attachments  as  far  cephalad  as  the 
central  end  of  the  azygous  vein  (Fig.  101).  Double  ligature  this 
vein  just  centrad  of  the  point  of  junction  of  the  cephalic  branch. 
Employ  the  tracer  in  isolating  the  vein  so  as  not  to  injure  other 
parts.     Then  divide  between  the  ligatures. 

Cut  the  aorta  opposite  the  head  of  the  8th  rib,  and  note  that, 
usually,  some  blood  remains  therein.  Grrasp  its  central  part  and 
draw  it  ventro-cephalad,  cutting  the  intercostal  arteries  and  other 
connections  as  far  as.  the  origin  of  the  A.  suhclama  (Fig.  101,  102). 
Then  grasp  the  heart  and  lungs  together,  draw  them  ventrad  and 
divide  the  trachea  and  the  vessels  cephalad  of  the  heart  at  the  de- 
sired points,  and  the  organs  may  be  removed  from  the  thorax. 

§  837.  Separation  of  the  Heart  from  the  Lungs. — On  the  dorsal 
aspect,  at  the  bifurcation  of  the  trachea,  is  a  mass  of  connective  tis- 
sue and  fat  enveloping  a  dark  glandular  body.  Remove  these  with 
the  tracer  and  fingers  so  as  to  open  a  way  ventro-cephalad  to  the 
ventral  side  of  the  bifurcation.  With  the  tracer,  expose  the  bron- 
chus on  each  side,  and  note  that,  on  its  ventral  side,  the  lung  is  con- 
nected with  the  heart  by  a  group  of  vessels,  the  AA.  et  VV.  pul- 
monales.     Ligate  very  firmly  the  roots  of  the  lungs  and  divide  them 


PRESERVATION    OF    THE    HEART   IN   ALCOHOL.  321 

peripherad  of  the  ligatures,  and  thus  complete  the  separation  of  the 
heart  from  the  lungs. 

§  838.  Preservation  of  the  Heart  in  Alcohol.— For  the  study 
of  the  cardiac  cavities,  the  heart  should  not  only  be  hardened  in 
alcohol,  but  distended  therewith. 

Instruments  and  Materials. — Coarse  scissors ;  coarse  forceps ;  sharp  tracer  or  syringo- 
tome  ;  four  threads  for  ligatures,  or  two  threads  and  two  small  compressors ;  syringe  with 
canula  adapted  to  the  aorta  and  postcava  (a  rubber  bulb  syringe  is  most  convenient  in  some 
respects) ;  small  jar  or  glass  box  ;  95  per  cent,  alcohol,  about  250  cc.  ;  cotton ;  small  pins ; 
thread. 

At  the  the  time  of  first  preparing  a  heart  by  the  injection  of  strong  alcohol  into  the 
cavities,  we  were  unaware  that  it  was  recommended  by  Hyrtl  and  Mojsisovics  (A,  58). 
The  former  ascribes  (A,  305)  the  original  idea  to  Wm.  Hunter. 

§  839.  Removal  of  the  Pericardium.  —In  most  cases  this  should 
be  partly  removed.  Pinch  it  up  at  a  point  about  one  third  of  the 
distance  from  the  base  of  the  ventricles  to  the  apex  and  make  a 
transverse  incision.  Continue  this  incision  around  the  heart  so  as 
to  remove  the  apical  two  thirds  of  the  pericardium.  It  may  be  pre- 
served for  reference. 

§  840.  Removal  of  the  Blood. — The  little  blood  that  may  remain 
in  the  left  side  of  the  heart  can  be  easil}^  expelled  through  the  aorta. 
The  right  cavities  usually  contain  considerable  blood.  Remove  the 
ligatures  upon  the  postcava  by  carefully  pushing  entad  of  it  the 
point  of  the  sharp  tracer  or  the  syringotome.  If  it  has  been  tied  very 
tightly,  it  may  be  necessary  to  cut  off  the  end  of  the  vessel. 

Introduce  the  nozzle  of  the  syringe  into  the  postcava  and  inject 
water  carefully  ;  then  manipulate  the  right  auricle  and  ventricle  at 
the  same  time  so  as  to  expel  the  blood  through  the  postcava. 

§  841.  Tying  the  Vessels. — Tie  firmly  the  A.  brachio-cepJialica 
and  the  A.  subclavia  sinistra  at  about  1  cm.  from  their  respective 
origins  from  the  arcus  aorticus  (Fig.  102).  The  other  vessels  should 
have  been  tied  in  removing  the  heart,  and  the  aorta  and  postcava 
are  left  open  for  the  injection. 

§  842.  Injection  of  Alcohol.— A.  Into  the  left  side. — Insert  the 
canula  into  the  aorta  so  that  the  ligature  about  its  tip  may  be  just 
centrad  of  the  emergence  of  the  first  intercostal  artery.  Tie  it  in 
place,  and  prepare  a  second  ligature  for  tying  it  after  the  injection. 

Naturally,  the  progress  of  the  alcohol  is  checked  by  the  semi- 
lunar and  bicuspid  valves,  but  it  may  be  caused  to  pass  them  by 
holding  the  heart  with  the  apex  up,  and  manipulating  the  base  of 
the  aorta  and  the  base  of  the  left  ventricle.  When  the  auricle  and 
21 


322 


ANA  TOMICAL    TECHNOL  OGT. 


tlie  VY.  pulmonales  are  fully  distended,  apply  the  ligature  firmly 
and  remove  the  canula. 

B.  Into  the  right  side.  —In  like  manner  inject  through  the  post- 
cava,  but  no  special  manipulation  is  needed  for  the  liquid  to  fill 
the  ventricle  and  the  A.  pulinonalis. 

§  843.  Hardening, — The  heart  may  be  carefully  laid  in  strong 
alcohol  upon  cotton,  with  the  base  uppermost,  or  it  may  be  suspended 
by  a  thread  passed  about  a  small  pin  pushed  transversely  through 
the  extreme  apex  so  as  not  to  penetrate  the  ventricles.  After  two 
days'  immersion  it  will  be  fit  for  section  or  dissection. 

Injection  with  plaster, — See  explanation  of  Fig.  91. 


§  844  Table  of  the  Principal  Parts  and  Features  of  the  Heart  (Cardia). 


Hbmicardia  Sinistra  (Lbpt  ob 
Systemic  Portion). 

Hemicardia  Dextra  (Right  or 
Pulmonic  Portion). 

Special  Names. 

General  Names. 

Special  Names. 

A.  Great  Cavities  (Loculi). 
1.  Reception 

Auricula  dextra. 

2.  Delivery 

Ventriculus  dexter. 

Sinus ;  appendix 

B.    Divisions  of  Great 
Cavities. 

j  Sinus  ;      appendix  ;      fossa 
\      ovalis. 
"Base;  apex;  conus  arteriosus. 

Orificicum  aur. -vnt.  dxt. 

fVV.   praecava    et    postcava 
J      (from    the    body);    VV. 
*      cardiacae      s.     coronariae 
[     (from  the  heart). 

A.  pulmonalis  (to  the  lungs). 

( Septalis, 
Tricuspides ■<  Dorsal  is, 

(Ventralis. 
Chd.  tnd.  dxt. 

3.  Of  ventricles 

C.  Orifices  and  Vessels. 
\  1.  Auriculo-ventricularor) 
\         inter]  ocular. \ 

\  3.  Yasa  afferentia  (enter- ) 
\         ing  the  auricles). . . .) 

j  3.  Vasa  efferentia  (leav-[ 
\         ing  the  ventricles). . .  \ 

D.  Valves  (Valvae)  and  the 
Parts  associated  there- 
with. 
j  1.  Auriculo-ventricular     [ 
\          valves ) 

3.  Chordae  tendineae 

3.  ColumnsB  carneae 

4   Arterial  valves 

Orificium  aur.  vnt.  sin 

VV.  pulmonales  (from  the  { 
lungs) \ 

Aorta  (to  tlie  body),  A  A.  car- ' 
diacae  a.  coronariae  (to  the 
heart  from  the  base  of  the 
aorta) 

Bicuspides«.mi- jSeptalis,    \ 
trales ]  Lateralis.  \ 

Chd.  tnd.  sin 

Clm.  cm.  sin 

Clm.  crn.  dxt. 

Sejpilunaresaor.  |g°-«M 

C  ^      .,                    ( Ventralis, 
^Semilunares        3  Dextra, 
]     pulmonales..  ]g,„igtra. 
jSn.    Vis.    dxt.    (3),    Valva 
\     Thebesii. 

tlCl cl-     -^L          C 

5.  Sinus  Valsalvae 

( Sinistra. ) 
Sn.  Vis.  sin.  (3) 

E.    Single  Parts  belonging  equally  to  Both  Sides.- 
tum  ventriculare.    3.  Ductus  arteriosus. 


-1.  Septum  auriculare.    3.  Sep- 


THE    CARDIAC    CAVITIES. 


323 


Fig.  93. — Diagrammatic  representation  of  the  heart,  the  great  vessels,  the  pulmonic 
and  svstemic  capillaries. 

In  tiiis  diagram,  as  in  Fig.  91,  the  heart  is  seen  from  its  dorsal  (posterior)  aspect ;  hence 
its  right  and  Ifft  portions  correspond  in  position  with  the  right  and  left  of  the  observer  (§  56). 

Most  of  the  parts  are  shown  by  outlines  only,  but  the  ventricular  and  anricular  walls 
are  shaded,  and  the  lines  representing  the  aorta  and  pulmonary  artery  are  made  a  little 
heavier  than  those  representing  the  vena  cava  and  pulmonary  vein. 

The  course  of  the  blood  is  indicated  by  arrows,  but  the  action  of  the  parts  will  be 
considered  in  Part  III.  The  difference  between  the  valves  upon  the  two  sides  will  be 
explained  in  connection  therewith. 


^IracfieiL 


s-  sy stem c COL 


M ml ccn-iia   ^e y.i:'rcL 


Fig.  92. — Diagram  op  the  Cardiac  Cavities,  etc.  ;  Dorsal  Aspect. 


§  845.   The  special  objects  of  this  diaprram  are  : — 

1.  To  represent  the  more  essential  parts  of  the  heart  in  a  single  figure,  to  give  their 
full  technical  names,  and  to  indicate  the  relations  of  the  cavities  to  each  other  and  to  the 
great  vessels. 

2.  To  illustrate  the  physiolojrical  fact  that  the  mammalian  heart,  in  the  normal  adult, 
really  consists  of  two  organs  whose  cavities  have  no  direct  communication  whatever. 

3.  To  show  the  many  points  of  resemblance  between  the  right  and  left  portions. 

4.  To  indicate  the  relations  of  the  two  portions  of  the  heart,  through  their  afferent  and 
efferent  vessels,  with  the  lungs  and  the  other  organs  of  the  body,  and  thus  to  justify  the 
apparent  paradox  that  v.'hereas,  anatomically,  the  heart  may  properly  be  described  as  a 
single  and  approximately  mesal  organ,  situated  between  the  two  lateral  masses  of  the 
lungs,  physiologically,  the  right  and  left  portions  of  the  heart  are  separated,  on  the  one  hand 
by  the  lungs  and  on  the  other  by  the  rest  of  the  body.     Anatomically,  there  are  two  lungs 


324  ANATOMICAL    TECHNOLOGY. 

and  the  heart  lies  between  them  ;  physiologically,  the  lungs  form  a  single  organ  which  is 
inte) posed  between  the  two  hearts  ;  Wilder,  1. 

§  848.  The  diagram  (Fig.  92)  differs  from  an  accurate  representation  of  any  actual 
section  of  the  cat's  heart  in  the  following  respects  : — 

1.  The  separation  of  the  right  and  left  portions  {hemicardice),  involving  the  splitting 
of  the  septa  auriculare  et  ventriculare  and  the  elongation  of  the  ductus  arteriosus. 

2.  The  non-crossing  of  the  aorta  and  A.  pulmonalls  and  the  deflection  of  the  former  to 
the  right  instead  of  the  left. 

3.  The  representation  of  the  cardiac  (coronary)  vessels  by  the  beginnings  of  the  two 
arteries  and  the  ends  of  two  of  the  veins. 

4.  The  representation  of  the  systemic  veins  {postcaca,  prmcava  andF.  azygos)  by  a  single 
vessel  here  named  V.  cam.  ' 

5.  The  representation  of  the  several  VV.  pulmonales  by  a  single  vessel. 

6.  The  representation  of  the  two  lungs  by  a  single  and  simple  sac. 

7.  Tiie  distance  from  cne  another  upon  the  arcus  aorticus  of  the  origins  of  the  vessels 
supplying  the  head  and  arms,  A  A.  hrachiO'Cephalica  et  subclaxia  sinistra  {A.  hrcph.,  A. 
sbclv.). 

8.  The  representation  of  the  branches  and  capillaries  of  the  aorta  and  A.  pulmonalis  by 
only  thre&  divisions  of  each  vessel. 

9.  The  representation  of  the  semilunar  and  auriculo  ventricular  valves  in  each  case  by 
a  pair  of  lines. 

10.  The  omission  of  the  fret-work  upon  the  ental  aspect  of  the  walls,  especially  of  the 
ventricles  and  the  auricular  appendices. 

11.  The  positions  and  points  of  attachment  of  the  appendices  and  of  the  veins  which 
enter  the  auricles  have  been  assigned  with  a  view  to  convenience  of  representation  rather 
than  absolute  accuracy. 

12.  The  omission  of  the  ductus  thoracicus,  which  might  have  been  made  to  join  the 
proximal  portion  of  the  Vena  cava. 

§  847.  The  right  and  left  portions  (Jiemicardim)  of  the  heart  agree  with  each  other  in 
the  following  respects  : — 

1.  Their  primary  division  into  an  auricle  (auricula),  which  is  relatively  c^pliallc  in  posi- 
tion, irregular,  rounded  and  thin  walled  ;  and  a  ventricle  (ventriculus),  which  is  caudal  in 
position,  regular,  'pointed  and  thick  walled. 

2.  The  division  of  each  auricle  into  a  larger  sinus  and  a  smaller  appendix. 

3.  The  communication  of  each  auricle  with  its  ventricle  by  a  slightly  constricted  orifice^ 
guarded  by  valves  of  irregular  shape. 

4.  The  attachment  of  cusps  of  the  free  edges  of  the  auriculo-ventricular  valves  to  the 
ventricular  walls  by  fibrous  chordoe  tendinem  springing  from  the  apices  of  columnoe  carneoz. 

5.  The  free  communication  of  the  auricles  with  veins  {VV.  cavm  and  VV.  pulmonaricB)., 

6.  The  exit  from  the  ventricles  oi  arteries  {aorta  and  A.  pulmonalis). 

7.  The  guarding  of  each  arterial  orifice  by  three  similar  and  regular  semilunar  valves. 

8.  The  expansion  of  each  artery  opposite  the  valves  to  form  three  sinuses  of  Vohalva. 

9.  The  aorta  and  A.  pulmonalis  are  united  by  a  fibrous  band,  the  ductus  arteriosus,] 
the  normally  impervious  remnant  of  a  vessel  which,  in  the  foetus,  permitted  the  blood  toj 
pass  from  the  latter  vessel  into  the  former  peripherad  of  the  origin  of  the  vessels  {AA.l 
hrachio-cephalica  et  suhclavia  sinistra)  which  carried  the  purer  maternal  blood  to  the  headj 
and  arms. 

§  848.  The  right  and  left  portions  {hemicardice)  of  the  heart  differ  in  the  following 
respects : — 


LIST    OF   ABBREVIATIONS.  335 

1.  The  afferent  vassels  ( VV.  cavm)  of  tlie  former  come  from  the  body  in  general,  those 
of  the  latter  {VV,  pulmonales)  from  the  lungs.  The  efferent  vessels  of  the  former  {A A. 
pulmonales)  go  to  the  lungs,  and  those  of  the  latter  {aorta)  to  the  hody  in  general. 

2.  From  two  of  the  aortic  sinuses  of  Valsalva  arise  the  two  AA.  cardiacce  which  are 
distributed  to  the  substance  of  the  heart  itself. 

3.  Into  the  right  auricle  open  the  VV.  mrdiaccE  which  come  from  the  substance  of  the 
heart. 

4.  The  septal  wall  of  the  right  auricle  presents  an  oval  depression,  fossa  oralis,  the 
Indication  of  a  thin  portion  of  the  septum  which,  in  the  foetus,  was  absent,  so  as  to  permit 
the  existence  oiihe  foramen  ovale  {%  868). 

5.  The  lateral  walls  of  the  left  ventricle  are,  upon  the  whole,  from  two  to  three  times 
the  thicker. 

6.  The  right  ventricle  is  prolonged  as  a  conu^  arteriostis  from  which  arises  the  A.  piU- 
moncdis. 

7.  The  auriculo -ventricular  valves  on  the  right  form  three  divisions,  hence  named  VV. 
tricuspides,  while  those  of  the  left  form  two,  hence  named  bicuspides  or  mitral. 

8.  The  foregoing  are  real  and  constant  distinctions  between  the  right  and  left  hearts. 
In  addition,  in  the  diagram,  on  the  left  side,  the  semilunar  valves  are  represented  as  closed, 
forming  bags  whose  convexities  bulge  toward  the  ventricle  as  if  pressed  upon  by  a  column 
of  liquid  in  the  artery  ;  the  tricuspid  valves  are  also  closed,  as  if  by  the  pressure  of  a  vol- 
ume of  liquid  in  the  ventricle ;  they  are  restrained  from  being  carried  into  the  auricle  by 
the  chordm  tendinem. 

§  849.  List  of  Abbreviations  of  Cardiac  Hames. — Ao..^  Aorta, 
§  851. — Arc.  ao.^  Arcus  aorticus,  §  854. — A.  hrcpli.^  Arteria  brachio- 
cephalica,  §  855. — A.  crd.^  Arteria  cardiaca,  §  856. — A.  plm.^  Ar- 
teria pulmonalis,  §  857. — A.  sbclv.,  Arteria  subclavia,  §  858. — Aur. 
dxt,  Auricula  dextra,  §  859. — Aur.  sin.,  Auricula  sinistra,  §  860. — 
Chd.  t)id.,  Chordse  tendinese,  §  864. — Clm.  car.,  Colunma?  carnese, 
§  865. — Con.  art,  Conus  arteriosus,  §  866. — Bet.  art.,  Ductus  ar- 
teriosus, §  867. — Fs.  ov.,  Fossa  ovalis,  §  868. — Orf.  aur-vnt,  Orifi- 
cium  auriculo-ventriculare,  §  870. — Pcv.,  Postcava,  §  871. — Prcv., 
Prsecava,  §  872. — Spt.  aur..  Septum  auriculare  s.  auricularum, 
§  873. — Spt.  vnt.  Septum  ventriculare  s.  ventriculorum,  §  874. — 
8n.  aur.  dxt.  Sinus  auriculae  dextrse,  §  875. — Sn.  aur.  sin..  Sinus 
auriculae  sinistrse,  §  876. — 8n.  cor.  s.  crd.,  Sinus  coronarius  s.  car- 
diacus,  §  877. — Sn.  Vals.,  Sinus  Valsalvae,  §  878.— Tdcl.  Low., 
Tuberculum  Loweri,  §  880. —  Vlv.  die,  Valva  bicuspis,  §  881. — 
Vlv.  slmr.,  Valva  semilunaris,  §  882. —  Vlv.  Tiib.,  Valva  Thebesii, 
§  883. —  Ylv.  trc,  Valva  tricuspis,  §  884. —  V.  az..  Vena  azygos, 
§  885.— F.  crd..  Vena  cardiaca  s.  coronaria,  §  887. —  F.  ct..  Vena 
cava,  §  886.— F.  plm..  Vena  pulmonalis,  §  888. —  Ynt.  dxt,  Ventric- 
ulus  dexter,  §  889.— F7?i.  sin.,  Ventriculus  sinister,  §  890. 

§  850.  Descriptive  List  of  the  Parts  of  the  Heart. — The  be- 
ner  may  find  it  advisable  to  read  over  this  list  with  reference  to 


32G  ANATOMICAL     TECHNOLOGY. 

the  figures,  before  undertaking  the  dissection  and  detailed  examina- 
tion of  the  organ.  Later,  however,  he  should  again  consult  it  for 
the  descriptive  portions. 

§  851.  Aorta  (a^.),  ^o,  (Fig.  91,  92,  93,  94,  95,  96,  99, 100,  101, 102, 
103,  107,  108). — The  large  artery  springing  from  the  base  of  the  left 
ventricle  and  giving  ofi*  branches  to  all  parts  of  the  body.  Its  cen- 
tral portion  (as  shown  in  Fig.  91,  101,  102,  108)  is  strongly  arched, 
and  is  thence  named  arcus  aorticus.  It  then  passes  through  the 
thorax  into  the  abdomen,  and  the  diaphragm  therefore  indicates 
the  point  of  demarcation  between  the  aorta  ihoracica  and  the  aorta 
ahdomlnaUs.  This  vessel  is  sometimes,  as  by  Stowell  (1),  called 
A,  (Arteria)  aorta^  but  the  single  word  seems  to  be  sufficient. 

§  852.  Apex  (ventriculi). — The  smaller  or  caudal  end  of  either 
ventricle,  and  of  either  the  cavity  or  the  fleshy  wall  thereof  (Fig.  91, 
92,  93,  98). 

§  853.  Appendix  (auriculse)— The  ventral  extension  of  either  auri- 
cle (Fig.  91, 95, 96). — The  other  and  larger  division  of  the  auricle  is  the 
sinus.  The  limits  of  the  two  divisions  are  not  clearly  defined,  but 
as  a  whole  the  ental  surface  of  the  appendix  presents  more  corruga- 
tions. Sometimes  the  appendix  is  called  auricle^  and  the  entire 
cavity  is  then  known  as  atrium. 

§  854.  Arcus  aorticus  {az.)y  arc.  ao. — The  arch  of  the  aorta 
(Fig.  92,  101,  102,  108).— See  aorta  (§  851)  and  the  explanation  of 
Fig.  101,  102. 

§855.  Arteria  brachio-cephalica  ((^^.),  J..  SrepA. — The  brachio- 
cephalic artery  (Fig.  91,  92,  101, 102,  103,  107,  108).— See  explana- 
tion of  Fig.  102. 

§  856.  Arteria  cardiaca,  A.  crd. — A  cardiac  or  coronary  artery 
(Fig.  91,  92,  93,  94,  102). — There  are  two  cardiac  arteries,  arising 
from  the  aortic  sinuses  of  Valsalva  and  distributed  to  the  substance 
of  the  heart.  As  seen  in  Fig.  102,  they  arise  respectively  from  the 
right  and  left  sinuses,  and  are  distributed  to  the  corresponding  re- 
gions. The  mouth  of  the  right  one  is  shown  in  Fig.  94.  It  is  not  cov- 
ered hy  the  valve  when  the  latter  is  opened  ;  see  W.  T.  Sedgwick  (./). 

§  857.  Arteria  pulmonalis  {az.\  A.  i^lm. — The  pulmonary  ar- 
tery (Fig.  91,  92,  93,  95,  99,  100).— This  springs  from  the  conus 
arteriosus  at  the  base  of  the  right  ventricle,  passes  sinistro-cephalad 
and  ventrad  of  the  aorta,  and  divides  into  two  (A.  ^plm.  dxL  and  A. 
'plm.  sin.\  which  carry  blood  to  the  right  and  left  lung  respectively. 


.  PARTS    OF    THE    HEART.  327 

§  858.  Arteria  subclavia,  A.  shclv.  sin, — The  subclavian  ar- 
tery (Fig.  91,  92,  101, 102,  108). — This  arises  from  the  arc^.?  aorticus 
just  jjeripherad  of  the  A.  bracMo-cephalica.  On  Fig.  92  the  abbre- 
viation sin.  is  omitted. 

§  859.  Auricula  dextra,  aur.  dxt — The  right  or  pulmonary 
auricle  (Fig.  91,  92,  93,  94,  95,  99,  100).— The  cavity  of  the  auricle 
is  divisible  into  a  larger  sinus,  dorsal  in  position  and  smoother 
walled,  and  a  smaller  appendix,  more  ventral  in  position  and  with 
corrugations  and  recesses  upon  the  ental  aspect  of  the  wall.  Into 
the  right  auricle  venous  blood  is  poured  through  the  postcava^ 
prcecava  and  the  W.  cardiacoe. 

§  860.  Auricula  sinistra,  aur.  sin. — The  left  or  pulmonary  auri- 
cle (Fig.  91,  92,  93,  95,  96,  99,  100).— Like  the  right,  the  left  auricle 
presents  a  sinus  and  an  appendix.  Purified  blood  is  brought  to 
it  by  the  W.  pulmonales. 

%  861.  Basis. — The  base  of  either  ventricle  or  of  the  entire  ven- 
tricular portion  of  the  heart. 

§  862.  Capillariae  pulmonales — The  capillaries  of  the  lungs. — 
In  Fig.  92,  these  are  diagrammatically  represented  by  three  subdi- 
visions of  the  single  A.  pulmonalis.  In  reality  they  are  exceedingly 
lumerous  and  minute. 

§  863.  Capillariae  systemicae — The  systemic  capillaries. — The 
exceedingly  numerous  and  minute  subdivisions  of  the  branches  of 
bhe  aorta  are  represented  in  Fig.  91  by  three. 

§  864.  Chordae  tendineae,  chd.  tnd. — The  tendinous  cords  con- 
lected  with  the  free  borders  of  the  auricula-ventricular  nalves  on 
both  sides  (Fig.  92,  93,  94  A).— These  cords  are  very  strong  and 
inelastic.  Their  other  ends  are  connected  with  the  apices  of  the 
columncB  carnece,  and  they  serve  to  prevent  the  free  borders  of  the 
bicuspid  and  tricuspid  valves  from  being  forced  back  into  the  auri- 
cles at  the  time  of  the  ventricular  systole. 

§  865.  Columnae  cameae,  elm.  car. — The  fleshy  columns  of  the 
ventricles  (Fig.  91,  93,  94,  97,  98).— There  are  two  large  columns 
in  the  left  ventricle  and  a  variable  number  of  smaller  ones  in  the 
right.  Consisting  of  muscle  like  the  ventricular  walls  themselves, 
these  columns  are  supposed  to  contract  and  thus  keep  the  chordoe 
tendinecB  from  becoming  lax  at  the  ventricular  systole. 

§  866.  Conus  arteriosus  {dxt.\  con.  art. — The  arterial  cone  or 
bulb  from  which  springs  the  A.  pulmonalis  (Fig.  91,  92,  94,  100). — 


328  ANATOMICAL    TECHNOLOGY. 

This  is  a  conical  prolongation  of  the  base  of  the  right  ventricle  at  its 
left  corner,  and  is  continued  into  the  A.  pulmonalls.  In  a  heart  of 
average  size  its  length  is  about  1  cm.  Since  there  is  no  correspond- 
ing prolongation  of  the  left  ventricle,  the  semilunar  valves  of  the 
aorta  are  upon  a  "lower"  level  than  those  of  the  A.  pulmonalis, 
^.  ^.,  they  are  nearer  the  apex  of  the  ventricle  (Fig.  94).  The 
ental  surface  of  the  conus  is  smooth. 

§  867.  Ductus  arteriosus  {az.\  dot.  art.  (Fig.  92). — By  an  over- 
sight, this  very  significant  remnant  of  an  important  foetal  structure 
is  not  represented  upon  any  of  the  figures  of  actual  preparations. 
It  is  slight  and  easily  overloolied  in  even  a  somewhat  careful  exam- 
ination of  the  parts.  We  have  never  observed  any  depression  cor- 
responding with  its  attachment  to  the  A.  pulmonalis^  and  in  the 
aorta  the  depression  is  usually  very  indistinct.  The  ductus  begins 
at  the  cephalic  side  of  the  A.  pulmonalis,  just  centrad  of  its  bifurca- 
tion, and  extends  very  obliquely  along  the  slight  interval  between 
the  artery  and  the  aorta,  to  become  attached  to  the  latter  a  little 
peripherad  of  the  origin  of  the  A.  subclavia  sinistra,  and  some- 
what at  the  ventral  as  well  as  caudal  side  of  the  vessel. 

§  868.  Fossa  ovalis  {az.\  Fs.  ov. — The  oval  depression  upon  the 
right  side  of  the  septum  auriculare  (Fig.  91). — This  is  not  dis- 
tinctly represented  upon  any  of  the  figures  of  actual  j3reparations. 
It  is  most  easily  seen  after  the  lateral  wall  of  each  auricle  has  been 
removed  and  the  septum  is  held  between  the  eye  and  the  light.  At 
about  the  middle  of  the  septum  there  will  appear  a  thinner  area, 
bounded  cephalad  and  ventrad  by  a  more  or  less  distinct  thicken- 
ing. The  thin  portion  is  usually  oval,  and  measures  about  5x2.5 
mm.  In  the  kitten  before  birth,  the  thin  area  is  more  or  less  com- 
pletely absent,  so  that  the  two  auricles  communicate,  and  the  blood 
from  the  postcava  passes  through  the  orifice,  the  Fm.  ovale,  into  the 
left  ventricle.  Respecting  the  significance  of  the  fossa  ovalis  and  its 
appearance  in  the  human  heart,  see  the  works  cited  and  also  Quain, 
A,  II,  799-803,  and  Dalton,  A,  699. 

On  the  left  side  of  the  septum,  the  area  corresponding  with  the 
position  of  the  Fs.  ovalis  is  sometimes  quite  smooth,  but  more  often 
presents  (as  in  Prep.  360,  Museum  of  Cornell  University)  a  crescentic 
elevation  at  its  dorsal  side. 

§  869.  Hemicardia  dextra — The  right  side  or  portion  of  the 
heart. — Since  the  entire  organ  is  called  Jieart  or  cardla,  it  is  logi- 
cally incorrect  to  speak  of  the  two  sides  as  the  right  heart  and  the 


PARTS    OF    THE    HEART.  329 

left  heart.  The  term  liemicardia  is  analogous  with  the  words  Tiemi- 
spJiere^  Jiemipteron,  etc.  The  left  auricle  and  ventricle  constitute 
the  hemicardia  sinistra. 

Hemiseptum  auriculare  and  hemiseptum  ventriculare. — l^oi 
only  ideally,  as  in  Fig.  92,  but  actually  may  the  interventricular 
septum  be  divided  so  that  a  portion  remains  as  the  mesal  wall  of 
either  ventricle.  Strictly  speaking,  each  of  these  parts  is  not  a  sep^ 
turn,  but  a  Jieviiseptum,  but  practically  the  latter  term  need  seldom 
be  employed. 

§  870.  Orificiiun  auriculo-ventriculare  dextrum,  07/".  aur.-nnt 
dxt. — The  right  auriculo- ventricular  orifice  (Fig.  92,  93,  96,  97,  99). 
— This  is  the  slightly  constricted  communication  between  the  right 
auricle  and  ventricle.     It  is  guarded  by  the  tricuspid  valves. 

The  similar  orifice  between  the  left  auricle  and  ventricle  is 
guarded  by  the  bicuspid  valves. 

§  871.  Postcava  {az.\pcv. — The  posterior  or  caudal  vena  cava 
or  Y.  cava  inferior  s.  ascendens  (Fig.  91,  92,  95,  101,  §  955).— This 
large  vein  enters  the  right  auricular  sinus  on  its  dorsal  aspect  near 
the  ventricle.     Respecting  the  name,  see  §  886. 

§  872.  Praecava  {az.\  prcv. — The  anterior  or  cephalic  vena  cava 
or  V.  cava  superior  s.  descendens  (Fig.  91,  92,  93,  95,  101,  §  919). 
— This  opens  into  the  right  auricular  sinus  at  its  cephalic  aspect, 
just  dorsad  of  the  arch  of  the  A.  pulmonalis. 

§  873.  Septum  auriculare  {az.\  spt.  aur.—T\ie  partition  be- 
tween the  right  and  left  auricles  (Fig.  93,  95,  96,  99).— This  is  hardly 
thicker  than  the  lateral  auricular  wall  and  is  very  thin  at  the  fossa 
ovalis.  In  Fig.  93,  what  is  named  septum  embraces  also  the  mass 
of  connective  tissue  between  the  aorta  and  the  bifurcation  of  the 
septum  proper  as  seen  in  Fig.  96.  The  septum  is  really  between 
only  those  larger  portions  of  the  auricles  known  as  the  sinuses. 

§  874.  Septum  ventriculare  {az.),  spt.  imt. — The  partition  be- 
tween the  right  and  left  ventricles  (Fig.  93,  97,  98).— The  septum  is 
about  as  thick  as  the  lateral  wall  of  the  left  ventricle. 

§  875.  Sinus  (auriculae  dextrse),  sn.  aur.  dxt.— The  sinus  or 
larger  and  more  dorsal  portion  of  the  right  auricle  (Fig.  91-96). — 
Its  walls  are  smoother  within  than  those  of  the  appendix.  Into  it 
open  the  postcava,  the  prcecava  and  the  V.  cardiaca. 

§  876.  Sinus  (auriculae  sinistrse),  sn.  aur.  sin. — The  left  auricu- 
lar sinus  (Fig.  91,  92,  93,  95,  96).— The  larger  and  more  dorsally 


330  AKATOMICAL     TECHNOLOGY, 

placed  portion  of  the  left  auricle.     Entad  its  walls  are  smoother 
than  those  of  the  appendix,  and  into  it  open  the  YV.  pulmonales. 

%  Sll.  Sinus  coronalis  s.  cardiacus,  sn.  cor.  s.  crd. — The  sinus 
of  the  coronary  vein. — This  is  not  distinctly  shown  in  any  of  the 
figures.  Its  position  is  indicated  on  Fig.  91  by  the  abbreviation 
V.  crd.  Both  the  sinus  and  the  semilunar  valve  at  its  opening  into 
the  auricle  are  readily  found  by  examining  the  dorso-caudal  angle 
of  the  auricle  close  to  the  septum.  Into  the  sinus  open  not  only  the 
principal  Y.  cardiaca,^  but  one  or  two  smaller  ones. 

§  878.  Sinus  Valsalvae,  sn,  Yals. — One  of  the  six  sinuses  of 
Valsalva  (Fig.  92,  94,  96).— There  are  three  of  these  at  the  mouth 
of  the  aorta  and  that  of  the  A.  pulmonalis.  Each  sinus  may  be 
described  as  an  enlargement  of  the  base  of  the  vessel  occupying  a 
little  less  than  one  third  of  its  circumference.  Each  is  partly  cov- 
ered by  a  semilunar  valve  (§  882),  and  is  thus  open  peripherad  but 
closed  centrad  or  toward  the  ventricle.  As  in  man,  they  may  be 
designated  as  approximately  dorsal,  dextral  and  sinistral  in  the 
aorta,  and  ventral,  dextral  and  sinistral  in  the  pulmonary  artery. 
From  the  right  and  left  aortic  sinuses  arise  the  two  AA.  cardlacce 
or  "coronary"  arteries. 

§  879.  Trabecula  tenuis. — This  name  is  applied,  provisionally, 
to  a  slender  and  apparently  fibrous  filament  which,  in  the  prepara- 
tion from  which  Fig.  98  was  taken,  spans  the  right  ventricle  near  its 
apex.  Its  septal  end  springs  from  an  independent  little  muscular 
elevation  ;  its  lateral  end  is  attached  to  the  base  of  a  columna  car- 
nea.  In  Fig.  98  it  is  represented  much  too  large  ;  it  is  really  hardly 
thicker  than  a  spider's  thread.  Can  it  be  the  insignificant  repre- 
sentative  of  the  "moderator  band"  of  Ruminants  (RoUeston,  B, 
25-35)^ 

§  880.  Tuberculum  Loweri— The  tubercle  of  Lower. — This  and 
the  Eustachian  valve,  both  of  which  have  been  described  in  connec- 
tion with  i^Q  fossa  oimlis  of  some  Mammals,  we  have  not  yet  deter- 
mined the  distinct  presence  of  in  the  cat.  According  to  Hyrtl 
(A,  290),  the  former  rarely  if  ever  appears  in  the  human  heart. 

§  881.  Valva  bicuspis,  vlv.  hie. — One  of  the  two  bicuspid  or 
mitral  valves  (Fig.  92,  93,  96,  97,  99).— As  in  man,  one  of  these  wide 
valves  is  at  the  left  or  lateral  side  of  the  auriculo-ventricular  orifice, 
and  the  other  is  toward  the  septum,  thus  also  overhanging  the 
entrance  to  the  aorta. 


PARTS    OF    THE    HEART  331 

§  882.  Valva  semilunaris,  vlv.  slmr.— One  of  the  six  semilunar 
or  sigmoid  valves  (Fig.  92,  94,  96,  100). — The  mouths  or  bases  of 
the  aorta  and  A,  pulmonalls  are  guarded  each  by  three  of  these 
valves.  Their  free  borders  are  nearly  even,  and  naturally  look 
peripherad.  Like  the  sinuses  of  Valsalva^  which  they  partly  cover, 
the  three  aortic  valves  are  approximately  dorsal,  dextral  and  sinis- 
istral  respectively,  while  those  of  the  pulmonary  artery  are  approx- 
imately ventral,  dextral  and  sinistral. 

§  883.  Valva  Thebesii  {az.\  vlv.  Thb.—The  valve  of  Thebesius.— 
This  name  has  been  applied  to  the  semilunar  valve  at  the  entrance 
of  the  y.  cardiaca  through  the  sinus  coronarius  into  the  right 
auricle  (Quain,  A,  II,  246).     It  is  easily  seen  in  the  cat. 

§  884.  Valva  tricuspis,  vlv.  trc. — One  of  the  three  tricuspid 
valves  (Fig.  92,  93,  94,  96,  97,  99).— As  in  man,  one  of  these  right 
auriculo-ventricular  valves  is  nearer  the  septum,  while  the  other  two 
are,  approximately  and  relatively,  dorsal  and  ventral.  There  is 
considerable  variation  in  their  form.  Usually  the  free  border  is  quite 
irregular,  but  in  the  preparation  from  which  Fig.  94  was  taken, 
the  free  border  is  even  and  the  chordae  tendinese  are  attached  at  the 
lateral  edges. 

§  885.  Vena  azygos  {az.\  V.  az. — The  azygous  vein  (Fig.  91,  99, 
101,  §  920). — This  vein  opens  into  \he  prcBcava  about  1  cm.  peripherad 
of  its  junction  with  the  right  auricle. 

§  886.  Vena  cava  (a^.),  V.  cv. — The  adjective  cava  is  applied  to 
either  of  the  two  great  veins  through  which  the  impure  blood  is 
brought  from  the  organs  in  general  to  the  right  auricle.  It  is  more 
commonly  emj)loyed  for  the  longer  and  larger  of  the  two,  which 
traverses  the  abdomen  and  penetrates  the  diaphragm.  By  Owen 
(A)  the  two  are  designated  as  the  postcaval  and  prcecaval  veins. 
The  vessels  are  so  large,  so  important  and  so  often  mentioned,  that 
we  have  ventured  to  omit  the  vena  and  to  designate  them  as  simply 
prcBcava  and  postcava.  In  the  diagram  (Fig.  92)  the  single  Vena 
cava  represents  both  prcecava  and  postcava. 

%  887.  Vena  cardiaca,  Y.  crd. — One  of  two  or  more  cardiac  or 
coronary  veins  (Fig.  91,  92). — The  blood  which  has  traversed  the 
tissues  of  the  heart  itself  is  returned  to  the  right  auricle  by  one 
large  and  one  or  more  smaller  veins,  all  of  which  open  into  a  small 
sinus  {sn.  coronalis),  which  has  been  described  above  (§  877). 

§  888.  Venae  pulmonales — The  pulmonary  veins  (Fig.  91,  92). — 


332  ANATOMICAL    TECHNOLOGY. 

Near  the  left  auricle  these  form  three  wholly  distinct  groups  of  two 
each,  which  fronr  their  position  may  be  called  dextral,  sinistral  and 
intermediate  or  dorsal. 

Disregarding  the  smaller  subdivisions,  some  of  which  are  not 
represented  in  the  figures,  each  group  consists  of  two  trunks  which 
open  into  the  auricle  by  a  common  sinns  of  varying  depth. 

The  intermediate  and  the  sinistral  sinus  are  indistinctly  seen  in 
Fig.  95  at  the  ends  of  the  lines  drawn  from  the  abbreviation  TF., 
but  the  separate  orifices  of  the  veins  do  not  appear.  The  dextral 
sinus  could  not  be  shown  in  the  same  figure,  but  its  position  is 
indicated  approximately  by  the  s  of  the  word  septum. 

When  traced  to  the  lungs,  it  is  found  that  the  dextral  and  sin^ 
istral  groups  come  from  the  right  and  left  lungs  respectively,  but 
that  of  the  two  large  constituents  of  the  intermediate^  the  one  nearer 
the  right  comes  from  the  lung  of  that  side,  and  the  other  from  the 
left. 

In  man,  there  are  usually  two  pulmonary  veins  on  each  side, 
opening  independently  into  the  auricle. 

§  889.  Ventriculus  dexter,  ?)7i^.  dxt — The  right  or  pulmonary 
ventricle  (Fig.  91,  92,  93,  94,  97,  98,  99).— This  is  not  only,  as  its 
name  implies,  relatively  dextral  in  position,  but  also,  in  the  natural 
attitude  of  the  organ,  somewhat  more  ventral  than  the  left  ventricle. 
Its  walls  are  markedly  thinner  than  those  of  the  left,  and  its  cavity 
does  not  so  nearly  reach  the  apex  of  the  organ.  The  ental  surface 
of  its  walls  presents  numerous  elevations  and  depressions.  In  addi- 
tion  to  the  columnar  carnece  and  the  trahecula  tenuis^  there  are 
many  muscular  trabeculsD  passing  obliquely  from  one  part  of  the 
wall  to  another,  forming  a  sort  of  coarse  network.  The  sinistro- 
cephalic  corner  of  the  ventricle  is  devoid  of  reticulations,  and  is 
prolonged  as  the  conus  arteriosus  (§  866). 

§  890.  Ventriculus  sinister,  vnt.  sin.— The  left  or  systemic  ven- 
tricle (Fig.  91,  92,  93,  94,  97,  98,  99).— This  is  not  only  sinistral, 
but  also,  relatively,  somewhat  more  dorsal  in  position  in  the  natu- 
ral attitude  of  the  heart.  Its  lateral  walls  are  2-3  times  as  thick  as 
those  of  the  right  ventricle,  and  its  cavity  reaches  more  nearly  to 
the  apex  of  the  organ.  In  the  contracted  state  of  the  heart,  the  left 
ventricle  occupies  the  more  space  on  account  of  the  greater  thick- 
ness of  the  walls  (Fig.  93)  ;  but  the  thinner  walls  of  the  right  yield 
more  to  the  pressure  of  an  injection,  and  its  cavity  generally  appears 
more  capacious  (Fig.  91,  97,  98).     It  presents  two  large  columnse 


LONGITUDINAL    SECTIONS    OF    THE    HEART. 


333 


carnese  and  some  other  slight  irregularities,  but  not  the  reticulations 
which  exist  in  the  right  ventricle.  The  aorta  springs  from  the  base 
of  the  ventricle  close  to  the  septum. 


o(e>ctra 

Valsalvae 
Vatva 

Valva  tricuspis 


Veniri  cuius 
Sinister 

yzntncuius 
dexHr 


Fig.  93.— The  Dorsal  Part  of  the  Heart, 

SEEN  FROM  THE  VeNTRAL  AsPECT  :    X  1.5. 


Fig.  94.— a  Longitudinal  Segment  of 
THE  Heart,  showing  the  Right  Sinus 
OF  Valsalva  and  Cardiac  Artery; 
xl.5. 


§  891.  Explanation  of  Fig.  93. — Longitudinal,  dextro-sinistral  section  of  the  entire 
heart,  seen  from  the  ventral  surface. 

Preparation. — This  was  the  heart  of  a  very  large  male  (castrated)  cat,  a  gift  from 
Messrs.  MeMn  &  Badger  of  Boston,  Mass.  From  the  same  cat  were  taken  the  scapula 
and  humeri,  ribs  and  vertebrae  shown  in  Fig.  43-46,  50,  68-71. 

The  heart  was  not  injected  or  prepared  in  any  special  way,  excepting  hardening  in 
alcohol  upon  cotton.  Hence  the  cavities  are  small  and  the  auricles  corrugated.  When 
hard,  it  was  divided  by  a  longitudinal  dextro-sinistral  incision  with  a  large  sharp  scalpel. 
The  dorsal  part  is  here  represented  ;  the  ventral  part  is  a  little  the  thicker. 

The  special  object  of  the  preparation  is  to  exhibit  the  relative  positions  and  oonnections 
of  the  four  great  cavities  with  the  auriculo-ventricular  valves.  In  addition,  there  are 
shown,  (A)  the  entrance  of  the  prcpcnva^  which  has  been  longitudinally  divided ;  (B)  the 
point  of  entrance  or  mouth  of  the  postcata,  as  a  dark  spot  at  the  beginning  of  the  word ; 
(C)  the  aorta  and  pulmonary  artery  {A.  plm.) ;  both  are  transected,  the  former  just  at  the 


334  ANATOMICAL     TECHNOLOGY. 

place  of  origin  of  i}\eA.  Itrachio-cepJialica  ;  (D)  the  right  and  left  cardiac  arteries  imbedded 
in  the  fat  at  the  line  of  junction  of  the  auricles  and  ventricles  ;  (E)  the  part  marked  septum 
auricularum  is  not  truly  part  of  the  septum,  but  the  thick  tissue  ventrad  of  it  as  seen  in 
Fig.  96. 

§  893.  Fig.  94 — Preparation. — This  represents  nearly  the  dextro- ventral  fourth  of 
the  heart,  but  the  two  planes  of  longitudinal  section  are  not  quite  at  right  angles  with 
each  other,  and  the  preparation  is  so  placed  that  both  are  foreshortened. 

The  special  object  is  to  show  the  dextral  wall  of  the  central  part  of  the  aorta,  with  the 
dextral  sinus  Valsalvce  and  the  mouth  of  the  corresponding  A.  cardiaca.  This  latter  is 
seen  to  be  so  high  up  that  It  would  not  be  covered  by  the  V.  semilunaris  even  when  fully 
extended  (§  856). 

At  the  left  are  seen  the  cavity  of  the  convs  arteriosus,  with  a  very  small  piece  of  the 
A.  pulmonaUs,  and  one  of  the  semilunar  valves,  which  is  decidedly  upon  a  higher  (more 
cephalic)  level  than  those  of  the  aorta  (§  866). 

It  will  be  understood  that  the  communication  between  the  right  ventricle  and  the  conus 
is  behind  the  septum  ventriculare. 


Fig.  95. — ^Transection  of  the  Auricles,  Caudal  Aspect  ;    x  1.5. 

§  893.  Fig.  95-98 — General  Description  and  Mode  of  Preparation.— These  four 
figures  represent  transections  of  the  same  heart  through  the  auricles  (Fig.  95,  96)  and 
through  the  ventricles  (Fig.  97,  98),  and  as  viewed  from  the  caudal  (Fig.  95,  97)  or  the 
cephalic  (Fig.  96,  98)  aspect.  The  heart  had  been  distended  and  hardened  with  alcohol 
(§  842),  and  was  then  transected  with  the  large  scalpel  at  two  levels. 

In  comparing  the  figures  as  representing  continuous  parts  of  the  same  organ.  Fig.  97  is 
to  be  imagined  inverted  upon  Fig.  98,  the  inversion  being  from  left  to  right ;  then  Fig.  96  is 
to  be  placed  upon  Fig.  97  without  inversion,  and  Fig.  95,  inverted  as  before,  upon  Fig.  96. 
The  entire  heart  will  then,  in  the  mind,  be  as  if  viewed  from  the  base  with  the  ventral 
aspect  toward  the  observer,  so  that  the  right  and  left  sides  are  inverted  as  compared  with  his. 

§  894.  Fig.  95— The  Interior  of  the  Auricles  from  the  Caudal  Aspect.— The  figure 
illustrates  the  extent  of  the  sej^tum  avriculare,  and  the  fact  that  the  auricular  sinuses 
appear  upon  the  dorsal  aspect,  while  on  the  ventral  there  are  to  be  seen  only  the  appen- 


TBANSECTION    OF   THE    AURICLES. 


335 


dices  projecting  on  either  side  of  the  aorta  and  pulmonary  artery.  Of  these  two  vessels, 
the  former  is  seen  to  be  nearly  in  liue  with  the  auricular  septum,  while  the  latter,  at  this 
level,  is  ventro-sinistrad  of  it.  The  middle  of  the  length  of  the  septum  auriculare  should 
have  been  thinned  to  indicate  the  position  of  the  fossa  ovalis  (§  8(58).  In  the  left  auricle 
the  two  ends  of  the  line  which  is  interrupted  by  the  abbreviation  VV.  point  respectively 
to  the  positions  of  the  dextral  and  sinistral  sinuses  of  the  pulmonary  veins  (§  888) ;  the 
third  or  intermediate  sinus  is  overhung  by  the  auricular  septum,  and  its  position  is  indi- 
cated approximately  by  the  s  of  the  word  septum.  A  little  of  the  complete  wall  of  the 
postcava  remains,  but  the  place  of  attachment  of  the  prsecava  is  indicated  only  by  an 
unshaded  area. 

§  895.   Fig.  96 — The  Auricles  and  Auriculo-ventricular  Orifices  seen  from  the 


Fia.  96.— Transection  of  the  Auricles,  Cephalic  Aspect;    xl.5. 


Cephalic  Aspect.— In  addition  to  the  features  in  common  with  Fig.  95,  this  figure  illus- 
trates the  following  points  : — 

(A)  The  relative  positions  of  the  three  semilunar  valves  of  the  pulmonary  artery, 
namely,  ventral,  dextral  and  sinistral. 

(B)  The  fact  that  the  aortic  valves  are  upon  a  lower  (more  caudal)  level  than  the  pul- 
monary, the  former,  indeed,  not  distinctly  appearing  unless  the  preparation  is  so  held  as 
to  admit  the  light  directly  into  the  vessel  (§  866). 

The  auriculo-ventricular  valves  are  not  especially  well  shown,  but  the  form  of  the  two 
unshaded  areas  indicates,  approximately,  the  fact  that  of  the  two  bicnspides  (§  881),  one  is 
lateral  and  the  other  septal,  while  of  the  three  tricuspides  (§  884),  one  is  septal  and  the 
others  respectively  dorsal  and  ventral  (more  strictly  dorso-lateral  and  ventro  lateral). 

In  the  right  auricle,  the  word  sinus  designates  the  general  cavity  of  the  auricle  aside 
from  the  appendix ;  but  in  the  corner,  and  pointed  at  by  the  words  sinus  and  septum,  is 
the  location  of  the  small  sinus  of  the  cardiac  veins  (%  887). 

§  896.  Fig.  97.— The  Ventricular  Cavities,  from  the  Cephalic  Aspect.— In  this 
and  Fig.  98,  the  most  striking  features  are  (A)  the  greater  thickness  of  the  lateral  wall  of 
the  left  ventricle,  in  relation  to  its  office  of  propelling  the  blood  over  all  parts  of  the  body, 
and  (B)  the  larger  size  of  the  cavity  of  the  right.  The  difference  of  size  is  artificial,  and 
due  to  the  less  resistance  offered  by  the  thinner  wall  to  the  pressure  of  the  injected  alcohol. 

In  the  left  ventricle  is  seen  the  cut  end  of  one  of  the  columnae  carneae,  still  attached  to 


336 


ANA  TOMJ  CA  L    TECHNO L  OGY. 


Fig.  97. — Transection  of  the  Ventricles,  Caudal  Aspect;    xl.5. 

the  lateral  bicuspid  valve  by  its  chordae  tendinese.     In  the  right,  the  surface  adjacent  to 
the  place  of  exit  of  the  pulmonary  artery  is  seen  to  be  smoother  than  in  other  parts 


*^^^^!^  t 


^^^  carntoTc 

Fig.  98. — Transection  of  the  Ventricles,  Cephalic  Aspect  ;    x  1.5. 

§  897.  Fig.  98— The  Ental  Aspect  of  the  Apices  of  the  two  Ventricles.— In  addi- 
tion to  points  in  common  with  Fig.  97,  this  figure  well  displays  the  very  numerous  reticu- 
lations and  trabeculce  of  the  right  ventricle,  and  especially  the  presence  of  a  very  delicate 
fibrous  band,  provisionally  named  trabeeula  tenuis,  which  connects  the  septum  with  the 
Hteral  wall  (§  879). 

DISSECTION  OF  THE  HEART. 

§  898.  After  tlie  careful  inspection  of  the  organ  as  a  whole,  and 
the  study  and  comparison  of  the  various  sections  represented  in 
Fig.  93-98  (or  at  least  of  the  figures  if  such  preparations  have  not 
"been  made),  the  heart  should  be  dissected  as  follows  : — 


DISSECTION    OF    THE    HEART,  337 

Instruments  and  Materials. — Sharp  Charriere  scalpel ;  coarse 
or  medium  curved  scissors  ;  silver  probe,  syringotome  or  dull 
tracer ;  15  per  cent,  glycerin  ;  a  heart,  the  larger  the  better,  with  the 
pericardium  removed.  The  dissection  may  be  done  upon  a  fresh 
specimen  or  upon  one  simply  hardened  in  alcohol ;  it  is  easier, 
however,  if  the  organ  has  been  distended  and  hardened  with  alco- 
hol (§  842). 

§  899.  Auricula  dextra. — Pinch  up  with  the  forceps  a  bit  of  the 
lateral  wall  of  the  right  auricle,  for  example,  just  dorsad  of  the 
appendix,  and  remove  it  with  the  scissors.  Introduce  the  probe 
and  ascertain  the  points  of  emergence  of  the  postcava  and  prcecava. 
With  the  scissors,  remove  the  entire  lateral  wall,  including  that  of 
the  appendix,  but  leave  the  attachments  of  the  cavse. 

Note  (A)  the  smoothness  of  the  ental  surface  of  the  sinus  as  com- 
pared with  the  fretwork  in  the  appendix  ;  (B)  close  to  the  auriculo- 
ventricular  furrow,  just  caudad  of  the  postcava,  the  orifice  of  the 
sinus  coTonalis  (§  877),  guarded  by  the  valva  Thebesii  (§  883). 

§  900.  Ventriculus  dexter. — Pass  the  probe  through  the  orifi- 
clum  auTiculo-ventriculare  into  the  right  ventricle,  noting  that  no 
obstruction  is  offered  by  the  tricuspid  valves.  Ascertain  by  prob- 
ing the  limit  of  the  ventricular  cavity,  and  with  the  scalpel  make  a 
Y-shaped  flap  having  its  base  at  the  base  of  the  ventricle  and 
including  the  entire  lateral  wall. 

Turn  this  flap  toward  the  auricle  and  note  :  (A)  the  two  or  three 
columnce  carnecB  ;  (B)  the  smaller  trabecules ^  both  fleshy  and  ten- 
dinous ;  (O)  the  chordae  tendinese  passing  from  the  columns  or 
directly  from  the  ventricular  wall  to  the  borders  of  the  three  valvcB 
tricuspides  /  (D)  that  two  of  these  valves  (dorsal  and  ventral)  will 
be  moved  by  the  lifting  of  the  flap ;  the  third  (septal)  is  applied 
closely  to  the  septum,  and  its  chordse  are  very  short,  arising  either 
from  the  septum  directly  or  from  very  slight  elevations. 

§  901.  Conus  arteriosus  and  A.  pulmonalis. — Pass  the  probe 
sinistro-cephalad  through  the  conus  into  the  artery.  Then  introduce 
a  scissors  blade  in  the  same  direction  and  slit  both  up  along  the  most 
prominent  part  of  the  convexity.  On  divaricating  the  sides,  it  will 
be  found  that  the  incision  has  either  divided  the  ventral  semilunar 
valve  or  gone  between  it  and  the  dextral.  Note  (A)  the  three  valves; 
(B)  the  corresponding  sinuses  of  Valsalva ;  (C)  the  bifurcation  of 
the  A.  pulmonalis  into  right  and  left  branches  to  the  corresponding 
lungs. 


338  ANATOMICAL    TECHNOLOGY, 

Ventriculus  sinister. — It  is  easier  to  defer  the  examination  of 
the  left  auricle  until  after  the  simpler  ventricle  has  been  opened. 

With  the  scalpel,  make  a  longitudinal  incision  through  the 
lateral  wall  about  midway  of  the  width  of  the  ventricle.  This  will 
permit  a  view  of  the  cavity  without  injuring  the  massive  columnar 
carnese  w^hich  will  generally  appear  one  at  either  side.  Then  make 
a  transverse  incision  at  right  angles  with  the  basal  end  of  the  first, 
making  sure  that  it  is  on  the  ventricular  side  of  the  furrow  between 
the  auricle  and  the  ventricle.  With  the  scalpel,  remove  the  enclosed 
angles  of  the  wall  on  either  side  so  as  to  expose  the  cavity  as  much 
as  desirable.  Note  that  one  of  the  wide  bicuspid  'tooltes  is  applied 
against  the  septum  so  as  to  conceal  the  orifice  of  the  aorta. 

§  902.  Aorta. — Pass  the  scissors  blade  behind  the  septal  bicuspid 
valve  into  the  aorta  and  slit  it  up.  The  incision  will  probably  cut 
through  one  of  the  three  semilunar  valves.  Note  (A)  the  position  of 
these  valves,  dorsal^  dextral  and  sinistral;  (B)  the  corresponding 
sinuses  of  Valsalva  ;  (C)  the  orifices  of  the  right  and  left  cardiac 
arteries  from  the  dextral  and  sinistral  sinuses. 

Farther  peripherad,  note  (A)  the  origins  of  the  hradiio-cejpTialic 
and  left  subclavian  arteries  ;  (B)  in  some  cases,  at  the  opposite  side 
of  the  aorta  from  those  vessels,  a  slight  depression  indicating  the 
place  of  attachment  of  the  ductus  arteriosus. 

§  903.  Auricula  sinistra. — Returning  to  the  left  ventricle,  pass 
the  probe  into  the  left  auricle  and  ascertain  the  points  of  attach- 
ment of  the  pulmonary  veins  nearest  the  appendix.  Then  intro- 
duce a  scissors  blade  and  divide  the  parts  from  the  ventricle  just 
dorsad  of  the  appendix,  carefully  avoiding  the  veins  just  mentioned. 

Slit  up  the  appendix  to  its  tip.  Then  with  the  probe,  seek  out 
the  orifices  of  the  three  groups  of  pulmonary  veins  as  represented 
in  Fig.  91.  Cut  along  the  auriculo-ventricular  furrow  so  as  to  per- 
mit a  better  view  of  the  cavity.  Note  the  more  or  less  marked 
crescentic  fold  which  indicates  the  dorsal  margin  of  i\\e  fossa  ovalis. 
Hold  the  septum  between  the  eye  and  the  light  and  note  its  thin- 
ness at  that  place.  Examine  the  right  side  of  the  septum  for  the  J 
,        fossa  and  the  left  for  the  crescentic  fold  (§  868).  * 

FROZEN  SECTIONS   OF  THE   THORAX. 

§  904.  Figures  99  and  100  represent  respectively  the  caiidal  and  cpplialic  aspects  of  a 
frozen  transection  of  the  thorax,  the  thickness  of  the  section  being  a  trifle  over  1  cm.  The 
manner  of  preparation  has  been  described  in  §  334. 


FROZEN   SECTIONS    OF    THE    THORAX,  339 

These  two  figures  may  be  compared  with  Fig.  101,  103,  107  and  109  in  the  present 
work,  and  with  Plates  IV  and  V  of  Dwight's  "  Frozen  Sections  of  a  Child  "  (B) 

g  905.  Level  of  the  Sections. — So  far  as  we  can  judge  by  comparison  with  dissections 
and  by  the  collation  of  these  with  the  other  sections  of  the  same  cat,  the  centrum  of  the 
7th  thoracic  vertebra  appears  in  Fig.  99,  and  that  of  the  6th  in  Fig.  100,  the  intervertebral 
arthron  being  included  in  the  thickness  of  the  section.  The  section  includes  the  bifurcation 
of  the  trachea,  which  appears  as  a  mesal  tube  in  Fig.  100,  into  the  two  hroncM  which 
appear  in  Fig.  99  ;  since  plane  surfaces  only  are  shown,  the  ridge  at  the  place  of  bifurca^ 
tion  does  not  appear  in  Fig,  100.  Between  the  oesophagus  and  the  vertebra  in  Fig.  100 
appear  the  transections  of  the  MM.  longus  colli;  but  these  terminate  in  the  thickness  of 
the  section,  and  in  Fig.  99  the  Vena  azygos  is  seen  to  be  joined  by  fhe  first  intercostal  vein. 

§  906.  The  Heart. — From  the  fact  that  the  heart  was  injected  with  plaster,  while  tho 
lungs  were  not  injected  at  all,  the  former  occupies  a  disproportionally  large  space.  The 
natural  obliquity  of  the  organ  also  interferes  with  the  ready  appreciation  of  the  relations 
of  the  parts  which  appear  in  the  two  figures. 

In  Fig.  99,  the  right  and  left  correspond  with  those  of  the  observer,  while  they  are 
reversed  in  Fig.  100.  In  the  former,  the  vein  presented  includes  a  combination  of  the  spe- 
cial features  which  have  been  observed  in  the  longitudinal  section  (Fig.  93)  and  the  tran- 
sections (Fig.  96,  97).  The  non  injection  of  the  left  auricle  accounts  for  the  relatively 
larger  size  of  the  right  in  Fig.  99,  and  for  the  non-appearance  of  the  left  in  Fig.  100. 

In  Fig.  100,  not  only  are  the  right  and  left  parts  reversed  in  position  with  respect  to 
the  observer,  but  the  appearances  are  less  readily  comparable  with  what  are  shown  in  the 
other  figures  of  the  heart.  The  right  auricle  is  divided  near  the  point  of  entrance  of  the 
prcecava,  but  the  non-injected  left  auricle  just  escaped  ;  its  cephalic  end  might  fairly  have 
been  placed  in  the  vacant  area  just  sinistrad  of  {dextrad  of  on  the  figure)  the  word  A.  pul- 
monalis. 

§  907.  Pleura  (§  806). — In  both  figures  the  lines  representing  the  pleura  are  made  dis- 
proportionally heavy  to  facilitate  their  recognition. 

The  pleura  is  seen  to  form  a  continuous  line  upon  the  ental  aspect  of  the  thoracic  pari- 

etes,  to  be  reflected  off  at  each  side  of  the  vertebral  centrum  upon  the  adjacent  structures, 

and  then  to  follow  the  contour  of  the  lung  to  the  heart,  where  it  forms  the  ectal  lamina  of 

the  pericardium.     At  the  ventrimeson  it  is  reflected  again  upon  the  parietes.     Hence,  like 

the  peritoneum  (§  725),  each  pleura  is  a  closed  sac  with  continuous  walls,  and  the  viscera 

which  appear  to  be  within  its  cavity  are  really  outside  and  in  contact  only  with  its  ectal 

surface. 

^^B  §  908.    Mediastinum. — The  irregular  space  between  the  vertebra  and  the  pericardium, 

^^^  bounded  on  the  sides  by  the  undulating  line  of  pleura  as  it  approaches  the  roots  of  the 

^rongs,  is  the  mediastinum.     Within  it  are  the  oesophagus  and  trachea,  the  aorta  and  other 

vessels  and  nerves. 

§  909.  Septum  mediastinale. — At  the  ventrimeson  the  right  and  left  pleural  reflec- 
tions are  in  contact,  and  form  an  apparently  single  membrane  between  the  two  cavities, 
which,  as  may  be  demonstrated  very  easily  by  experiment,  *re  thus  entirely  disconnected. 
In  Fig.  99,  the  mediastinal  septum  so  formed  is  very  short,  but  in  Fig.  100,  the  pericardium 
is  at  some  distance  from  the  sternum  and  the  septum  is  correspondingly  extensive. 

In  man  (Quain,  A,  II,  Fig.  163;  Dwight,  B.  PI.  IV),  these  two  reflected  layers  of  pleura 
do  not  meet  at  the  level  of  the  heart,  and  the  small  space  between  them  is  called  the 
anterior  inediastinum.  For  comparison  with  man,  therefore,  the  single  mediastinum  of 
the  cat  should  be  called  dorsal  or  posterior. 

§910.    Pericardium. — Like  the  pleura,  the  pericardium  is  represented  upon  the  figures 
naturally  heavy  lines.     In  Fig.  99,  near  the  ventrimeson,  it  is  seen  to  consist  of  two 


340 


ANATDMTCA  L    TECHNO  LO  G  Y. 

xpKi  dofsimaalU 


'Raphe'  ventyl-ni'eaalLM 

PiCF.  99. — Frozein  Transection  of  the  Thorax  at  the  Heart,  Caudal  Aspect  ; 

X  1 A 

lamin£D  embracing  a  deposit  of  fat  {adeps  pericardii).  On  both  figures  the  ectal  lamina 
may  be  traced  to  the  root  of  the  lung  on  either  side,  wliere  it  is  reflected  to  form  the  vis- 
ceral pleura  of  those  organs,  and  to  the  ventrimeson,  where  it  is  refl,ected  at  the  septum 


FROZEN    SECTIOXS    OF    THE    THORAX. 


zu 


Fig.  100. — Frozen  Transection  of  the  Thorax,  Cephalic  Aspect  ;   x  1.5. 


mediasUnale  to  become  continiioas  with  the  parietal  pleura.  The  ental  lamina  is  reflected 
to  form  the  proper  serous  covering  of  the  heart.  At  the  dorsal  jxtints  of  junction  of  the 
two  laminae  are  the  phrenic  nevces. 

The  sternal  arteries  and  veins  appear  dorso-laterad  of  the  mesosterneber.     The  veins 
lie  mesad  of  the  arteries  (§  921). 

»§  911.    Nerves,  etc. — The  sympathie  trunks  {N.  sympathicus)  appear  j  ust  ventrad  cf 
heads  of  the  ribs  in  Fig.  99,  and  in  corresponding  places  in  Fig.  100. 


342  ANATOMICAL    TECHNOLOGY, 

The  vagi  {N.  'cagus)  lie  ventro-laterad  of  the  oesophagus  and  dorsad  of  the  roots  of  the 
lungs.  The  phrenics  {N.  'plirenicm)  lie  just  ventrad  of  the  roots  of  the  lungs,  and  at  the 
point  of  union  of  the  ectal  and  ental  laminae  of  the  pericardium.  The  recurrent  laryn- 
geal nerves  do  not  appear  at  these  levels. 

The  ductus  thoracicus  is  represented  by  a  circle  just  dorsad  of  the  aorta  ;  its  walls  are 
much  thinner  than  here  indicated,  and  are  collapsed  when  the  tube  is  empty.  See  Fig. 
103,  where,  however,  at  this  level,  the  duct  is  double. 


BLOOD  VESSELS  OF  THE  TRUNK. 

§  912.  Special  Instruments  and  Material.— Arthrotome  ;  scalpel ;  fine  and  coarse 
scissors  and  forceps ;  tracer ;  nippers ;  injecting  apparatus  and  material  (§§  130,  336). 

Arteries,  References.— Quain,  A,  I,  343 ;  Gray,  A,  75  ;  Cuvier,  A,  VI,  100  ;  Gegen- 
baur  (Lankester),  A,  585  ;  Hyrtl,  A,  643  ;  Bernard,  A,  244 ;  Milne  Edwards,  A,  III.  511 ; 
Leyh,  A,  566  ;  Owen,  A,  III,  532  ;  Chauveau,  A,  545  ;  Chauveau  (Fleming),  A,  515  ;  Gurlt, 
A,  555 ;  Straus-Durckheim,  B,  II,  183. 

Veins,  References.— Quain,  A,  I,  343  ;  Gray,  A,  564  ;  Cuvier,  A,  VI,  226  ;  Gegenbaur 
(Lankester),  A,  589  ;  Hyrtl,  A,  713  ;  Bernard,  A,  244  ;  Milne-Edwards,  A,  III,  570  ;  Leyh, 
A,  625 ;  Owen,  A,  III,  549  ;  Chauveau,  A,  636 ;  Chauveau  (Fleming),  A,  596 ;  Gurlt,  A,  656. 

§  913.  Preparation. — Inject  the  right  V.  jugularis  externa  witli 
fine  blue  mass  (§§  366  and  1450),  and  either  the  femoral  artery  or 
the  abdominal  aorta  with  thin  plaster  (§§  345,  352,  363). 

See  especially  §  596  (10)  for  the  method  of  dissecting  vessels  and 
nerves.  Vessels  when  uniiijected  may  be  distinguished  from  nerves 
or  bundles  of  connective  tissue  by  cutting  a  slit  in  them  and  demon- 
strating their  tubular  character  with  the  tracer. 

Table  of  the  Systemic  Veins  of  the  Trunk,  and  the  Portal  Veins 

(Fig.  101,  103,  107). 

The  Table  of  Veins  is  like  that  of  the  Arteries  (§  916),  inasmuch  as  the  larger  trunks 
are  placed  first.  It  should  be  remembered,  however,  that  the  larger  trunks  are  formed  by 
the  smaller  ones  instead  of  dividing  to  give  rise  to  the  smaller  ones,  as  with  the  arteries 
(§819). 

§   914.      THORAX    AND    NECK. 

VV.  cardiacae  (Fig.  91,  §  887). 

,c,Ma^  (  V.  azygos  (§  920). 

Praecava  (^  919) ]  V.  stemalis  (§  923). 

f  V.  vertebralis  (^  923). 
Vena  brachio-cephalica  (§  922).   |   V.  subclavia  (§  924). 

(The  two  brachio-cephalic  veins  {  (  V.  jugularis  interna, 

form  the  Prgecava) |   V.  jugularis  externa  (§  925). .    -J  V.  suprascapularis. 

(^  (v.  radialis. 


ARTERIES    OF    THE    TRUNK    AND    ARM. 


343 


915.     ABDOMEN. 


Postcava  (§  955). 


V.  phrenica  (§  956). 

VV.  liepatioe  (§  957). 

V.  adreiio-lumbalis  (g  958). 

V.  renal  is  (i^  959) V.  spermatica  sinistra. 

V.  ilio-lumbalis  (§  961). 

V.  iliaca  comn^unis  (§  963).  \  ^^  ^  ^^ 


Vena  portae  (§  953) 


V.  mesenterica  superior  (§  949). 

V.  mesenterica  inferior  (S^  950). 

V.  gastro-splenica  (§  951). 

V.  pan  creati  CO- duodenal  is  (§  953). 

V.  gastro-epiploica  (§  954). 

V.  coronaria  ventriculi  (§  954). 


Table  of  the  Systemic  Arteries  of  the  Trunk  and  Arm 

(Fig.  101,  102,  105,  107). 

A  brace  placed  after  an  artery  includes  the  branches  of  that  artery. 


§  916.    THORAX  AND  ARM. 


AA.  cardiacae  (§  856). 

A.  brachio-cephalica  (§  937), 


■! 


Aorta  thoracica  (§  936). .  ■{ 


A.  mediastinalis  (§  937). 
A.  carotidea  sinistra  (§  937). 
A.  carotidea  dextra  (g  937). 
f  A.  vertebralis  (§  984). 
A  costalis  superior  (§  936). 


I 


A.  subclavia  sinirtra  (§  930).  j  a.  .ternalis  (§  935) 

[  Axis  thyroideufi  (§ 
AA.  intercostales  (10  pairs),  (§  939). 
A.  bronchialis  (3),  (§  930). 
A.  cesophagaea  (3-4),  (§  931). 
AA.  lumbales  (3  pairs),  (§  933). 


j  A.  pen- 
/  cardiaca. 
937). 


subclavia  dextra  (§  933).     (Continuation  of  the  f  ^'  vertebralis  (^934) 
hrachio-cephalica  aft?r    the  origin    of  the   right  \  f'  T    H  ^"^Hltl  ^§  ^^^^• 

t  Axis  thyroideus  (§  937). 


carotid.). 


If  A  thoracica  anterior  (§  939). 
,  axillaris  (§  938).      (Continuation  of  either  A.  J  A.  thoracica  longa  (§  940). 
subclavia  peripherad  of  the  first  rib.) 1   A.  circumflexa  posterior  (§  941)  et 
L      subscapularis  (Fig.  103,  |  943). 


brachialis  (§  943),  (Continuation  of  the  Axillaris 
peripherad  of  the  origin  of  the  common  trunk  of 
the  circumflex  and  subscapular.) 


radialis  (§  944).     (Continuation  of  the  Brachialis 
in  the  antebrachium ;  see  also  §  945.) 


A.  circumflexa  anterior  (§  943,  A). 
A.  profunda  superior  (§  943,  B^. 
A.  nutriens  (§  945,  C). 
A,  anastomotica  magna  (§  943,  D). 

A.  radialis  recurrens  (§  944,  A). 
A.  ulnaris  recurrens  (§  944,  B). 
A.  interosseus  posterior  (§  944,  C). 
A,  interosseus  anterior  (§  944,  D). 
A.  ulnaris  (§  945). 


344 


ANATOMICAL    TECHNOLOGY, 


§  917.    ABDOMEN. 


Aorta  abdominalis 

flz.  (§965).  (Con- 
tinuation of  tlie 
thoracic  aorta, 
Fig.  101.) 


A.  coeliaca,  az. 
(§966) 


A.   hepatica 
(§966,B). 


A  A.  hepaticse 
A.  cystica. 


A.    gastro- 
duodenalis. 


A.  pylorica. 

A.  pancreatico-du- 

odenalis. 
A.  ^astro-epiploica 

d  extra. 


A.  coronaria  ventriculi  (§  966,  D). 
AA.  ventriculi  dorsales  (§  906,  E). 
A.    splenica     j  AA.  gastricjs  et  pancreaticae. 

(§  966,  F).    ]  A.  gastro-epiploica  dextra. 
A.  phrenica  (§§  966,  A,  968,  B). 
f  A.  colica  media  (§  967,  B). 


A.    mesenterica  su- 
perior, az.  (§  969). 

A.    ad  reno-lum balls 
(§970)., 

A.  renalis(§969)... 


I   A.  pancreatico-duodenalis  inferior  (§  967,  A). 
^   A  colica  dextra  (§  967,  C). 
I    A.  ileo-c£ecalis(§'967,  D). 
[^  Rami  intestini  tenuis  (§  967,  E). 
j  A.  adrenalis  (^  968,  A). 
(  A.  phrenica  (§§  968,  B,  966,  A). 
S  A.  adrenalis. 
")  A.  ureterica. 


A.  spermatica  (§  970), 
A.    mesenterica  in- 
ferior, «2.  (§  971). 
A.  ilio-lumbalis  (§  972), 
AA.  lum-bales  (§  974). 
A.  iliaca  externa  (§  973,  A). 
A.  iliaca  interna  (§  973,  B), 
A.  sacra  media  (§  973,  C). 


A.  colica  sinistra. 

A.  haemorrhoidalis  superior. 


Preparation— Fig.  101.— A  lean  cat  was  killed  with  chloroform, 
and  the  femoral  artery  and  vein  were  injected  with  red  and  blue 
plaster  respectively  (§§  352-362).  The  V.  jugularis  externa  was  then 
injected  cephalad  with  blue  gelatin  (§  366).  After  an  hour  the  ventral 
wall  of  the  entire  trunk  was  removed,  together  with  all  the  viscera, 
except  the  heart,  kidneys  and  urocystis,  and  enough  of  the  dia- 
phragm to  expose  the  vessels.  The  liver  was  cut  away  within 
about  1  cm.  of  the  postcava.  All  the  organs  were  then  freed  from 
fat  and  connective  tissue  with  the  iine  forceps,  tracer  and  scissors. 
It  was  necessary  to  proceed  with  great  care,  especially  in  separating 
the  ureter,  the  spermatic  vessels  and  the  vessels  into  which  the 
aorta  divides. 

The  urocyst  was  turned  caudad  so  as  to  expose  its  dorsal  surface. 

Fig.  101,  A  and  B,  required  no  special  preparation,  as  they  are 
simply  enlarged  diagrams  of  the  aorta  and  postcava  with  their 
branches. 


THE    BLOOD     VESSELS. 


345 


AortflhiL  imb. 


ho,.  101.— General  View  of  the  Blood  Vessels  ;  x  .3.    A.  Origin  of  the  Postcava. 
B.  Termination  op  the  Abdominal  Aorta. 


346  ANATOMICAL    TECHNOLOGY. 

Description  of  Fig.  loi. — A.  V.  fern.,  A.  V.  femorales — Femoral  artery  and  vein. 
A.  hypogastrica — The  hypogastric  or  superior  vesical  artery.  A.  epigastrica — The  deep 
or  inferior  epigastric  artery.  A.  il.  ext.,  A.  iliaca  externa — The  external  iliac  artery. 
A.  V.  il.-lumb.,  A.  V.  ilio-lumbales — The  ilio-lurabar  artery  and  vein.  A.  m.  i.,  A.  me- 
senterica  inferior,  az. — The  inferior  mesenteric  artery.  A.  sprm.,  A.  spermatica — The 
spermatic  artery.  Aorta,  az.  A.  renalis — The  renal  artery.  A.  m.  s.,  A.  mesenterica 
superior,  az. — The  superior  mesenteric  artery.  A.  coeliaca,  az. — The  cceliac  artery  or 
cceliac  axis.  A.  brcph.,  A.  brachio-cephalica,  az. — The  brachio-cephalic  or  innominate 
artery.  A.  subcl.,  A.  subclavia — The  subclavian  artery.  A.  strn.,  A.  sternalis — The 
sternal  or  internal  mammary  artery.  A.  carotidea — The  carotid  artery.  Adrn.,  Adrenale 
— The  adrenal  or  suprarenal  body.  Au.  dext..  Auricula  dextra — The  right  auricle  of 
the  heart.  Cardia,  az. — The  heart.  Dphrg.,  Diaphragma,  az. — The  diaphragm.  Gl. 
sbmx.,  Glandula  submaxillaris— The  submaxillary  salivary  gland.  Gl.  lym.,  Glan- 
dula  lymphatica — A  lymphatic  gland  or  pair  of  glands  just  cephalad  of  the  submaxillary. 
Lrnx.,  Larynx,  az.  M.  dgst.,  M.  digastricus — Digastric  muscle.  Praecava,  az.~ 
The  superior  or  descending  vena  cava.  Ren — The  kidneys  Thyr.,  Corpus  thyroi- 
deum — The  thyroid  body ;  the  two  are  connected  in  man.  Urocystis,  az. — The  urinary 
bladder.  Urethra,  az. — The  canal  leading  from  the  urocystis  to  the  exterior.  Ureter 
— The  canal  conveying  urine  from  the  kidney  to  the  bladder;  see  Fig.  85,  86.  V. 
sprm.,  V.  spermatica — The  spermatic  vein.  V.  rn.,  V.  renalis.  VV.  hepaticae  (10-12), 
az. — Hepatic  veins.  V.  az.,  V.  azygos,  az. — The  azygous  vein.  V.  strn.,  V.  ster- 
nalis— The  sternal  or  internal  mammary  vein.  V.  sbclv.,  V.  subclavia — The  sub- 
clavian vein,  V.  brcph.,  V.  brachio-cephalica — The  brachio-cephalic  or  innominate 
vein.  V.  jgl.  int.,  V.  jugularis  interna — The  internal  jugular  vein.  V.  jgl.  ext.,  V. 
jugularis  externa — The  external  jugular  vein.  V.  jgl.  ant.,  V.  jugularis  anterior. 
V.  trns.,  V.  transversa — A  large  vein  connecting  the  two  jugular  veins  across  the 
meson.  Vagus  and  Symp. — The  vagus  and  sympathic  nerves.  Vas  deferens— The 
canal  conveying  the  semen  from  the  testis. 

Description  of  Fig.  loi.  A,  B.— A.  sacra  med.,  A.  sacra  media,  az. — The  median 
sacral  artery.  A.  il.  ext.,  A.  iliaca  externa.  A.  il.  int.,  A.  iliaca  interna.  A.  hy- 
pogastrica— The  hypogastric  or  superior  vesical  artery.  A.  epg.,  A.  epigastrica— 
The  internal  or  inferior  epigastric  artery.  Aorta,  az.  A.  il.-lumb.,  A.  ilio-lumbalis 
— The  ilio-lumbar  artery.  Postcava,  az. — The  ascending  or  inferior  vena  cava.  V.  il. 
ext.,  V.  iliaca  externa — The  external  iliac  vein.  V.  il.  int.,  V.  iliaca  interna— The 
internal  iliac  vein.  V.  il.-lumb.,  V.  ilio-lumbalis — The  iliolumbar  vein.  V.  il.  com., 
V.  iliaca  communis. 

Fig.  102 — Preparation.— The  abdominal  aorta  of  an  adult  cat 
was  injected  with  red  plaster  (§  352).  After  an  hour  the  vessels 
were  carefully  isolated  in  the  thorax  and  in  the  right  arm  to  the 
middle  of  the  antebrachium.  This  was  done  by  removing  muscles, 
connective  and  other  tissues  with  the  scalpel,  tracer,  scissors  and 
fine  forceps.  The  pericardium  was  then  removed,  and  the  proper 
cardiac  arteries  (A A.  cardiacse)  were  isolated  for  1-2  cm.  Finally, 
the  auricles  and  part  of  the  ventricles  were  cut  away,  commencing 
peripherad  and  following  the  aorta.  After  the  aorta  with  its  semi- 
lunar valves  was  isolated,  the  entire  preparation  was  soaked  in 
Wickersheimer's  fluid  (§  300)  for  a  day  and  then  allowed  to  dry. 


A.C&iL  Sffsrior 


347 


stn* 


^c/vi 


Fig.  102. — The  Aorta,  with  its  Main 
Branches  in  the  Thorax  and  Right 
Arm;  Ventral  View;  xl.  A.  Origin 
OP  the  Carotid  Arteries;  x  1.  B,  C. 
Veins  with  Valves  ;  Quain,  A,  II,  174. 


\ 


The  Wickersheimer's  fluid  prevents  the  brittleness  that  is  so  olbjec- 
tionable  in  plaster  injected  vessels  that  are  dried. 

B  and  C — Preparation. — B.  A  segment  of  the  V.  jugularis 
externa  about  5  cm.  long  was  slit  lengthwise  and  placed  in  water, 
and  the  valves  floated  up  by  blowing  into  the  little  pockets  with  a 
blow-pipe. 

C.  The  external  jugular  or  femoral  vein  was  injected  peripherad 


348  ANATOMICAL    TECHNOLOGY. 

with  plaster,  and  after  the  plaster  was  moderately  hard,  a  hemi- 
section  of  the  vessel  was  made  and  the  plaster  removed. 

Explanation  of  Fig.  102. — Arcus  aorticus,  az. — The  arcli  of  the  aorta.  A.  brcph., 
A.  brachio-cephalica,  az. — The  brachiocephalic  or  innominate  artery,  A.  crd.  dext., 
A.  cardiaca  dextra — The  right  cardiac  or  coronary  artery.  A.  crd.  sin.,  A.  cardiaca 
sinistra — The  left  cardiac  or  coronary  artery.  A.  mdst.,  A.  mediastinalis,  az. — The 
mediastinal  artery.  A.  sbclv.  dext.,  A.  subclavia  dextra — The  right  subclavian  artery, 
a  continuation  of  the  brachio-cephalica.  A.  carotidea  sin.  (sinistra) — The  left  carotid 
artery  arising  from  the  brachio-cephalica  ;  see  A.  A.  vertebralis — The  vertebral  artery. 
This  arises  from  the  subclavian.  A.  cstl.  (costalis)  superior — The  superior  costal  artery. 
A.  strn.,  A.  sternalis — The  sternal  or  internal  mammary  artery.  A.  axillaris — The 
axillary  artery.  A.  thr.  ant.,  A.  thoracica  anterior — The  anterior  thoracic  artery. 
A.  thr.  (thoracica)  longa — The  long  thoracic  artery.  A.  subscapularis — The  subscap- 
ular artery.  A.  circumflexa — The  circumflex  artery  ;  a  common  trunk  arising  from  the 
axillary  bifurcates  to  form  this  and  the  preceding  artery  ;  in  man  they  arise  separately 
from  the  axillary.  A.  brachialis — The  brachial  artery.  A.  radialis — The  radial  artery. 
A.  ulnaris — The  ulnar  artery.  A.  interos.,  A.  interosseus — The  interosseus  artery. 
Costa  (1) — The  first  rib  in  cross  section.  Fm.  eptrch..  Foramen  epitrochleare.  VI. 
semilunares — The  semilunar  valves  at  the  beginning  of  the  aorta  ;  they  are  closed. 

Explanation  of  Fig.  102,  A. — Aorta,  az,  A.  brcph.,  A.  brachio-cephalica,  az. — 
The  brachio-cephalic  artery.  A.  sbcl.,  AA.  subclaviae — The  subclavian  arteries.  A.  c. 
dext.,  A.  carotidea  dextra.     A.  c.  sin.,  A.  carotidea  sinistra. 

The  carotids  may  arise  separately  from  the  brachio-cephalica  as  shown  in  Fig.  102,  or 
less  frequently  they  may  arise  by  the  bifurcation  of  a  single  trunk  which  is  given  off  from 
the  brachio-cephalica  (Fig.  102,  A).  This  common  trunk  is  called  by  Owen  (A,  III,  535), 
the  Ucarotid,  and  by  Milne-Edwards  (A,  III,  524),  carotide  primitive.  It  is  stated  by  the 
latter  that  this  is  the  normal  condition  in  the  cat,  lion,  dog,  etc. 

Fig.  102,  B. — Vein  slit  lengthwise  and  spread  out  to  show  two  pairs  of  valves. 

Fig.  102,  C. — Hemisection  of  a  vein  with  closed  valves. 

In  both»  B  and  C  the  central  end  is  uppermost.  C  shows  how  the  two  valves  pre- 
vent the  flow  of  blood  or  injecting  mass  toward  the  periphery.  Sometimes  but  a  single 
valve  exists,  in  which  case  the  action  is  less  efficient. 

§  918.  Posture  and  Exposure  for  the  Thoracic  Vessels. — Place 
the  cat  dorsicumbent,  with  the  arms  stretched  laterad  and  fastened 
with  cords  to  the  loops  in  the  edge  of  the  tray  (Fig.  76).  If  the  dis- 
section is  to  be  long  continued,  the  caudal  half  of  the  body  may  be 
removed  (§  234). 

Commence  on  the  right  side,  and  continue  the  incision  made  in 
exposing  the  V.  jugularis  for  injection  (§  913)  to  a  point  opposite 
the  base  of  the  xiphisternum,  carrying  the  incision  2  cm.  to  the 
right  of  the  ventrimeson;  then,  with  the  arthrotome,  cut  through 
the  sterno- mastoid  and  pectoral  muscles  (Fig.  72),  along  a  line  about 
2  cm.  to  the  right  of  the  ventrimeson  and  parallel  with  it.    Cut 


I 


VEINS    OF    THE    THORAX.  349 


the  thoracic  wall  on  the  right  side  at  the  junction  of  the  ribs  and 
their  cartilages,  and  then  across  the  meson  (Fig.  76,  §  825) ;  do  this 
with  either  the  arthrotome  or  bone  scissors.  Then  cut  with  nippers 
the  right  ribs  about  2  cm.  from  their  heads.  Turn  the  sternum  to 
the  left  and  the  wall  of  the  thorax  to  the  right.  This  will  expose 
the  heart,  right  lung,  prsecava,  the  abdominal  part  of  the  postcava, 
the  right  carotid  and  sternal  arteries,  and  the  axOlary  vessels  aud 
nerves  (Fig.  101,  105). 

VEINS  OF  THE  THORAX.    (See  Table,    §  914) 

W.  cardiacae  s.  coronarise  (see  §  887). 

§  919.  Frsecava,  az.^  and  its  branches  (Fig.  101). — The  prsecava 
His  the  prominent  vessel  extending  from  a  point  opposite  the  first 
^■rib  to  the  cephalic  part  of  the  right  auricle  of  the  heart.  It  is 
^^■loticeable  just  at  the  right  of  the  meson. 

H  §  920.  V.  azygos,  az.  (Fig.  99,  101,  107,  Y.  az.).— This  enters  the 
prsecava  just  cephalad  of  the  root  of  the  right  lung.  Grasp  the  right 
lung  and  turn  it  toward  the  left,  and  with  the  tracer  follow  the 
y.  azygos  peripherad.  At  regular  intervals  branches  from  the 
intercostal  spaces  enter  it.  Those  entering  it  near  its  termination 
are  large,  as  they  i-epresent  tlie  trunk  formed  by  the  union  of  two 
or  more  intercostal  veins.  Opposite  the  10th  rib  the  vein  becomes 
mesal  in  position,  and  is  dorsad  of  the  aorta  (Fig.  107,  V,  az.).  The 
V.  azygos  can  not  be  traced  caudad  of  the  diaphragm. 

§  921.  V.  sternalis  (Fig.  101,  V.  stm.,  99,  100).— About  opposite 
the^  3d  rib  the  sternal  veins  enter  the  prsecava  as  a  single  trunk,  but 
on  the  sternum  there  are  two  veins,  one  on  each  side  just  mesad 
of  the  corresponding  artery. 

§  922.  V.  brachio-cephalica  s.  innominata  (Fig.  101,  103,  107, 
V.  brcph.). — If  the  thymus  body  is  present,  separate  it  from  the 
prsecava.  About  opposite  the  1st  rib  the  prsecava  will  be  seen  to 
be  formed  by  the  union  of  two  nearly  equal  branches,  the  YY.  hra- 
cMo-cephaUccB.     Carefully  isolate  the  right  one. 

§  923.  V.  vertebralis. — Very  near  the  1st  rib  this  large  branch 
enters  the  dorsal  side  of  the  brachio-cephalica.  It  comes  from  the 
brain  through  the  vertebrarterial  canal  in  connection  with  the  ver- 
tebral artery  (Fig.  104,  A.  vrt.). 

§  924.   V.  subclavia  (Fig.  101).— Just  beyond  the  entrance  of 


350  ANATOMICAL     TECHNOLOGY. 

the  Y.  Tiertebralis  the  Y.  hracMo-cephalica  is  formed  by  the  union 
of  two  nearly  equal  branches,  the  subclavian  vein  and  the  external 
jugular.  The  V.  subclavia  may  be  traced  to  the  arm.  Later, 
in  studying  the  arteries  of  the  arm,  it  will  be  found  to  follow  them 
very  closely. 

§  925.  V.  jugularis  externa  (Fig.  87,  101,  103,  A).— This  large 
v6in  comes  from  the  head  and  face.  In  the  neck  it  is  covered  only 
by  the  skin  and  cutaneous  muscle.  Opposite  the  cephalic  part  of 
the  larynx  there  is  a  very  large  branch  connecting  the  jugulars  of 
the  two  sides  (Fig.  101,  Y.  trns,). 

The  external  jugular  receives  the  internal  jugular  (Fig.  101,  Y. 
jgl.  int.),  the  combined  trunk  of  the  subcutaneous  vein  of  the  arm 
and  the  V.  subscapularis.  This  trunk  is  shown  in  Fig.  101  just 
cephalad  of  the  abbreviation  Y.  Jgl.  int. 

Yeins  of  the  Abdomen^  see  §§  946-964. 

ARTERIES  OF  THE  THORAX  AND  ARM.    (See  Table,  §  916.) 

§  926.  Aorta  thoracica,  az.  (Fig.  91,  99,  100,  101,  102, 103, 107). 
— The  aorta  is  the  single  great  artery  arising  from  the  left  ventricle 
of  the  heart.  Through  it  and  its  branches,  every  part  of  the  body 
is  supplied  with  pure  blood.  To  expose  it,  remove  the  pericardium 
from  the  ventral  wall  of  the  heart,  also  the  prsecava,  the  septum 
mediastinale,  and  the  thymus  body  if  that  is  present.  The  aorta 
curves  sharply  to  the  left  (Fig.  102),  thus  making  the  arcus  aorti- 
cus.  The  branches  of  the  thoracic  aorta  are  as  follows,  commencing 
centrad : — 

AA.  cardiacae  s.  coronariae  (see  §  856). 

§  927.  A.  brachio-cephalica  s.  innominata,  az.  (Fig,  101,  102, 
103,  107). — This  arises  from  the  convexity  of  the  aortic  arch  and 
passes  almost  directly  cephalad.  Very  near  its  origin  it  gives  rise 
to  the  A.  mediastinalis,  which  passes  ventrad,  then  to  the  A.  ca- 
rotidea  sinistra  (Fig.  101,  102,  102,  A,  103,  A,  C,  and  107),  and 
the  A.  carotidea  d.extra.  Sometimes  the  two  carotids  arise  as  a 
single  trunk  (Fig.  102,  A).  After  the  origin  of  the  carotids,  the 
A.  brachio-cephalica  is  continued  as  the  A.  subclavia  dextra  (§  933). 

§  928.  A.  subclavia  sinistra  (Fig.  101,  A.  sbclv.,  102,  103,  A. 
sbclv.  sin.,  107,  A.  s.).— For  the  branches  of  the  A.  subclavia,  see 
§§  934-945  and  the  Table  (§  916). 


I 


BRANCHES    OF    THE    A.    SUBCLAVIA.  351 


§  929.  A  A.  intercostales  (10  pairs),  (Fig.  103,  AA.  costales). — The  intercostal  arteries 
are  given  off  from  the  dorsal  side  of  the  aorta.  Each  passes  to  an  intercostal  space  and 
divides  into  three  branches.  One  of  these  passes  ventrad  along  the  caudal  margin  of  the 
cephalic  of  the  two  ribs  between  which  it  extends  (Fig.  103) ;  another  goes  to  the  deep 
muscles  of  the  back,  and  the  third  enters  the  spinal  canal  through  the  intervertebraL^ 
foramen  ;  see  §  484.  ' 

§  930.  A.  bronchialis. — The  arteries  (2)  to  the  lungs  arise  either  from  the  aorta  itself, 
about  opposite  the  root  of  the  lung,  or  from  the  4th  intercostal  arteries.  They  accompany 
the  bronchi  to  the  lungs. 

§  931.  AA.  oesophageaae  (2-4),  (Fig.  107,  A.  oes.). — These  are  all  small  branches  and 
may  sometimes  arise  from  the  intercostals  instead  of  the  aorta. 

§  932.  AA.  lumbales  (2-3  pairs). — On  account  of  the  great  caudal  projection  of  the 
diaphragm,  2-3  pairs  of  the  lumbar  arteries  are  given  off  by  the  thoracic  aorta.  Rarely 
also  the  A.  cceliaca  arises  in  the  thorax  (§  966). 

§  933.  A.  subclavia  dextra  (Fig.  102,  A.  sbclv.  dext.).— This  is 
a  continuation  of  the  A.  bracMo-cephalica  peripherad  of  the  origin 
of  the  right  carotid.  Tear  away  carefully  any  connective  tissue  cov- 
ering it  as  far  peripherad  as  the  ectal  margin  of  the  first  rib.  Note 
the  large  nerve  covering  its  ventral  face.  This  is  the  xagus  (Fig. 
107  and  108 ;  the  recurrent  laryngeal  branch  may  be  seen  winding 
around  to  its  dorsal  side  (Fig.  108,  N.  1.  r.). 

Branches  op  the  A.  Subclavia. 

§  934.  A.  vertebralis.— This,  the  first  branch,  arises  from  the 
cephalic  surface  of  the  subclavian  and  passes  dorso-cephalad  to 
enter  the  vertebrarterial  canal.  It  passes  through  this  to  the  brain 
(Fig.  102,  103,  A.  vert.,  104,  A.  vrt.).  In  Fig.  104,  the  dorsal  wall 
of  the  vertebrarterial  canal  is  removed  and  the  artery  shows 
throughout  nearly  its  whole  extent. 

§  935.  A.  sternalis  s.  mammaria  interna  (Fig.  101,  A.  strn., 
102,  A.  strn.,  103, 107). — This  arises  from  the  ventral  surface  of  the 
A,  subclama  nearly  opposite  the  origin  of  the  A.  vertebralis.  It 
passes  ventrad  and  reaches  the  sternum  opposite  the  2d  mesoster- 
neber  (Fig.  49).  It  sends  two  or  three  small  branches  cephalad, 
then  extends  caudad  along  the  sternum,  and,  as  stated  above,  is 
laterad  of  the  sternal  vein.  Branches  of  this  artery  anastomose 
with  the  intercostal  arteries  (§  929),  with  the  phrenic  on  the  dia- 
phragm, and  with  the  epigastric  on  the  abdomen  (Fig.  101).  The 
left  sternal  also  usually  supplies  the  A.  pericardiaca  to  the  peri- 
cardium. 

§  936.  A.  intercostalis  superior  (Fig.  102,  A.  cstl.  superior).  — 
Just  as  the  subclavian  crosses  the  first  rib,  this  artery  arises  from 


352  ANATOMICAL    TECHNOLOGY. 

its  dorsal  surface.  It  extends  only  2-3  mm.  before  dividing  into 
two  trunks.  One  extends  caudad  on  the  ental  wall  of  the  thorax, 
supplies  the  1st  and  2d  intercostal  spaces,  and  then  passes  between 
the  1st  and  2d  ribs  to  be  distributed  to  the  deep  muscles  of  the  back. 
It  may  be  followed  by  tearing  away  the  muscles  with  the  tracer. 
Its  final  distribution  can  best  be  followed  after  the  removal  of  the 
scapula.  The  other  branch  passes  cephalad  nearly  parallel  with 
the  A.  vertebralis,  and  reaches  the  dorsal  side  of  the  great  nerve 
trunks  of  the  brachial  plexus  (Fig.  107).  It  is  distributed  to  the 
M,  serratus  magnus  (§  664).  After  the  section  of  the  brachial  ves- 
sels and  nerves  and  the  lateriduction  of  the  scapula,  it  may  be  very 
easily  traced. 

§  937.  Axis  thyroideus  (Fig.  102,  axis  thyr.). — Laterad  of 
the  1st  rib,  this  trunk  takes  its  origin.  It  passes  laterad  along  the 
ental  surface  of  the  clavo-trapezius  muscle,  sending  two  or  three 
branches  cephalad,  the  most  important  one  being  to  the  longus  coIW 
muscle.  The  part  extending  laterad  is  called  the  A.  surprascajpu- 
laris.  The  A.  suprascapular  is  supplies  the  clavicular  end  of  the 
3L  clavo-trapezius  and  the  lateral  surface  of  the  supraspinatus. 
Its  principal  branch,  however,  accompanies  the  suprascapular  nerve 
between  the  supraspinatus  and  subscapularis  muscles  and  enters 
the  suprascapular  fossa  about  opposite  the  base  of  the  acromion. 
In  the  supraspinous  fossa  it  divides  into  two  branches,  one  being 
distributed  to  the  muscles  in  the  supraspinous  fossa,  while  the 
other  passes  through  the  incisura  magna  (Fig.  45)  and  is  distributed 
to  the  structures  in  the  infraspinous  fossa  (Fig.  43).  The  scalpel 
as  well  as  the  tracer  should  be  used  in  tracing  this  vessel.     ^ 

§  938.  A.  axillaris  (Fig.  105,  A.  axl.). — This  is  the  continuation 
of  the  A.  subclama  laterad  of  the  1st  rib.  It  is  very  intimately 
associated  with  the  axillary  veins  and  nerves. 

§  939.  A.  thoracica  anterior  (Fig.  102  and  105,  A.  thr.  ant.).— 
This  is  the  first  branch  furnished  by  the  A.  axillaris.  It  arises  from 
the  ventral  surface  of  the  axillary  and  passes  with  the  nerve  of  the 
same  name  (Fig.  105)  ventrad  to  the  pectoral  muscles.  If  the  pecto- 
rals were  divided  at  the  proper  level,  this  artery  would  remain  with 
the  arm. 

§  940.  A.  thoracica  longa  (Fig.  102  and  105,  A.  thr.  longa).— 
It  arises  at  about  the  same  level  as  the  preceding  (§  939)  and  passes 
nearly  caudad,  sending  several  small  branches  to  the  pectorals,  but 


ARTERIES    OF    THE    THORAX    AXD    ARM.  353 

is  distributed  principally  to  the  ental  surface  of  the  M.  latissi- 
mus  (§  635). 

§  941.  A.  circumflexa  (Fig.  102,  105,  A.  crcm).— After  the  A. 
thoracica  longa  has  been  traced,  cut  through  the  pectoral  mass  and 
the  M.  epiirocJilearis  (§  681)  along  the  caudal  edge  of  the  M.  Mceps^ 
that  is,  nearly  parallel  with  the  humerus.  Turn  the  muscles  aside, 
and  there  will  be  exposed  the  vessels  and  nerves  of  the  brachium. 
About  oi3posite  the  trochin  (Fig.  45,  B)  the  axillary  artery  will  be 
found  to  divide  mto  two  slightly  unequal  parts  (Fig.  102,  105).  The 
larger  of  these,  the  hracMal  artery,  continues  along  the  arm  ;  the 
other,  the  common  trunk  of  the  circumflex  and  subscapular  arteries, 
proceeds  toward  the  surgical  neck  of  the  humerus  for  about  1  cm., 
when  it  divides  into  the  branches  just  named. 

The  circumflex  passes  between  the  subscapularis  and  teres  mus- 
cles in  company  with  the  circumflex  nerve  (Fig.  105) ;  it  winds  dor- 
sally  around  the  surgical  neck  of  the  humerus  and  is  distributed  to 
the  triceps  muscles,  and  its  terminal  branches  pass  to  the  euLal 
aspect  of  the  M.  clavo-deltoideus.  Demonstrate  these  by  separating 
the  acromio-  and  clavo-deltoid  muscles  and  raising  the  cephalic  bor- 
der of  the  latter.  Branches  of  the  circumflex  artery  and  nerve  will 
be  seen  ramifying  on  its  ental  aspect. 

§  942.  A.  subscapularis  (Fig.  102,  105,  A.  sbscp.).— This  arises 
Aw  common  with  the  circumflex,  as  stated  above  (§  941) ;  it  passes 
somewhat  laterad  and  is  distributed  principally  to  the  structures  in 
the  subscapular  fossa  (Fig.  44).  Several  branches  are  furnished, 
however,  to  other  structures,  viz.,  MM.  latissimus^  meditriceps  and 
dermo-Jvumeralis,  This  artery  and  its  branches  are  best  followed 
after  section  of  the  axillary  vessels  and  nerves. 

§  943.  A.  brachialis  (Fig.  102,  105,  A.  br.).— This  is  the  artery 
of  the  brachium.  It  is  a  direct  continuation  of  the  A.  axillaris  per- 
ipherad  of  the  origin  of  the  common  trunk  of  the  circumflex  and 
subscapular  (§§  941-2).  Isolate  it  with  the  tracer  by  tearing  away 
connective  tissue.  The  median  nerxe  and  brachial  min  lie  ectad 
of  it  and  should  be  removed  or  turned  aside.  In  its  course  along 
the  caudal  side  of  the  arm,  the  brachial  gives  rise  to  several  un- 
named muscular  branches  and  the  following  named  branches : — 

(A)  A.  circumflexa  anterior  (Fi^.  105.     It  is  the  small  vessel  passing  between  s  and  p 
of  "  iV.  m.  spiraHs  "). — It  passes  to  the  caudal  margin  of  the  M.  biceps,  and  then  sends  a 
f     branch  proximad  to  the  head  of  the  humerus. 

I  ;e3 


354  ANAT03IICAL    TECHNOLOGY. 

(B)  A.  profunda  superior  (Fig.  105),— This  arises  opposite  tlie  musculo-spiral  nerve 
(Fig.  105)  and  follows  its  course. 

(C)  A.  nutriens. — In  Fig".  105  it  is  the  vessel  passing  between  the  .4.  and  the  hr.  It  is 
represented  too  large.  It  passes  to  the  bone,  and  entering  the  nutrient  foramen,  is  distrib- 
uted to  the  shaft  of  the  humerus. 

(D)  A.  anastomotica  magna  (Fig.  105,  between  the  abbreviations  hmr.  and  trc,  near 
the  distal  end  of  the  humerus). — This  artery  passes  to  the  convexity  of  the  elbow. 

Upon  reaching  the  foramen  epitrochleare,  the  A.  brachialis  traverses  it  in  company 
■with  the  median  nerve  (Fig.  102,  105)  and  reaches  the  concavity  of  the  elbow. 

§  944.  A.  radialis  (Fig.  102,  105).— The  brachial  artery  distad 
of  the  concavity  of  the  elbow  is  continued  as  the  radial.  It  passes 
candad  of  the  tendon  of  the  Mceps  muscle  and  entad  of  the  prona- 
tor teres  (Fig.  105,  §  701).  About  opposite  the  middle  of  the  ante- 
hracMum  the  radial  artery  is  covered  only  by  skin  and  fascia.  At 
this  point  the  artery  divides  into  two  unequal  branches  ;  the  smaller 
or  ventral  one  follows  the  radial  nerve,  while  the  principal  one  in- 
clines dorsad,  and  just  distad  of  the  styloid  process  of  the  radius  it 
curves  around  to  the  dorsal  side  of  the  manus. 

To  expose  the  artery.,  divide  the  M,  pronator  teres  about  2  cm. 
from  its  origin  and  turn  the  two  ends  aside,  and  divide  longitudi- 
nally the  antebrachial  fascia  along  its  ventral  aspect. 

The  radial  artery  gives  rise  to  several  muscular  branches  that 
are  unnamed  and  to  the  following  named  branches : — 

(A)  A.  radialis  recurrens. — This  arises  in  the  concavity  of  the  elbow  on  the  caudal 
side  of  the  tendon  of  the  biceps  (Fig.  105).  It  is  distributed  to  the  various  structures  in 
the  concavity  of  the  elbow. 

(B)  A.  ulnaris  recurrens  (Fig.  105). — This  is  shown  in  the  figure  as  arising  from  the 
radial  opposite  the  point  where  it  crosses  the  M.  UceiJS.  It  extends  proximad  to  the  struc- 
tures at  the  convexity  of  the  elbow.  It  is  called  ulnar  recurreiu  on  account  of  its  distri- 
bution.    See  Quain,  A,  I,  408,  and  Gray,  A,  520. 

(C)  A.  interosseus  posterior. — This  artery  arises  from  the  ental  aspect  of  the  radial 
just  distad  of  the  tendon  of  the  biceps.  It  extends  nearly  directly  dorsad,  and  may  be 
demonstrated  by  tearing  away  the  muscles  surrounding  it. 

(D)  A.  interosseus  anterior  (Fig.  105,  A.  interosseus).— This  artery  arises,  either  sep- 
arately or  as  a  common  trunk  with  the  ulnar,  from  the  ental  aspect  of  the  radial  about 
3  cm.  from  the  Fm.  epitrocMeare.  It  passes  distad  along  the  antebrachium  on  the  ventral 
side  of  the  interosseus  ligament.  It  may  easily  be  followed  by  turning  the  radial  artery 
slightly  aside  and  then  separating  the  muscles  with  the  tracer. 

§  945.  A.  ulnaris  (Fig.  102  and  105).— In  man  the  ulnar  artery 
is  about  equal  in  size  to  the  radial,  and  the  division  of  the  brachial 
to  form  them  is  very  near  the  elbow  or  even  in  the  brachium  (Quain, 
A,  I,  403) ;  but  in  the  cat  the  ulnar  is  so  small  that  it  is  sometimes 
not  injected  at  all  with  plaster.    In  its  course  and  distribution  it  cor- 


I 


ABDOJTINAL    BLOOD     VESSELS,  355 


responds,  however,  witli  its  human  homologue.  It  arises  from  the 
radial  at  about  the  junction  of  the  proximal  and  middle  thirds  of 
the  antebrachium,  and  is  covered  at  its  origin  by  the  M.  pronator 
teres  (§  701).  It  passes  caudad  and  distad  along  the  ental  surface 
of  the  flexor  muscles,  and  joins  the  ulnar  nerve  at  about  the  point 
of  its  division  into  a  dorsal  and  ventral  branch.  The  artery  divides 
at  this  point,  and  the  two  branches  accompany  the  two  branches  of 
the  ulnar  nerve. 

ABDOMINAL  BLOOD  VESSELS. 

Posture. — Dorsicumbent,  the  limbs  fastened  laterad  with  cords 
(Fig.  76). 

§  946.  Preparation. — The  arteries  and  veins  should  be  injected 
with  plaster  as  directed  above  (§§  352-362),  or  the  thorax  may  be 
opened  and  the  thoracic  aorta  and  postcava  injected  caudad ;  the 
latter  is  easier  done  if  the  thorax  is  to  be  studied  on  a  different  cat. 

§  947.  Exposure. — About  half  an  hour  after  the  injection  is 
finished,  open  the  abdomen  as  directed  for  the  exposure  of  the 
viscera  (§  710). 

Vena  Port^.    (See  Table,  §  915.) 

The  study  of  the  portal  vessels  will  be  greatly  facilitated  by  injecting  them.  To  do 
this,  turn  the  duodenum  to  the  left,  and  extending  along  the  mesoduodenum  (§  736),  near 
the  edge  of  the  duodenal  part  of  the  pancreas,  will  be  seen  a  large  vessel  filled  with  blood 
( V.  mesenterica  superior).  Inject  this  vessel  toward  the  liver,  inserting  the  canula  about 
opposite  the  caudal  end  of  the  pancreas.  Employ  uncolored  plaster  or  that  colored  with 
chrome  green  or  yellow.  All  the  larger  portal  vessels  will  be  filled  except  the  peripheral 
part  of  the  V.  mesenterica  superior,  and  that  may  be  filled  by  reversing  the  direction  of 
the  canula 

It  will  be  necessary  to  change  the  position  of  the  viscera  often  in 
Lcing  the  portal  vessels. 

§  948.  V.  mesenterica  superior,  az.  (Fig.  103,  107,  V.  m.  s.). — 
lis  collects  the  blood  from  the  small  intestine.  Trace  it  from  the 
>int  where  it  was  injected,  first  peripherad  along  the  small  intes- 
le,  and  then  centrad  to  a  point  opposite  the  pylorus. 

§  949.  V.  mesenterica  inferior,  az.  (Fig.  107). — This  usually  empties  into  the  pre- 
ing  about  opposite  the  ampulla  of  Vater  (Fig.  84),  or  it  may  empty  into  the  following, 
in  man.     It  comes  from  the  large  intestine. 

§  950.   V.  gastro-splenica,  az. — This  joins  the  portal  slightly  nearer  the  liver  than  the 
ding  (§  950). — It  comes  from  the  spleen,  from  part  of  the  stomach  and  from  the  gastro- 


t 


356  A NA TOJIICAL  " TECHXO LOGY. 

splenic  part  of  the  pancreas.     Trace  it  to  these  parts.     It  may  also  receive  the  vessels 
mentioned  in  §§  9i9,  950. 

§  951.  V.  portaB,  a^.— The  trunk  formed  near  tlie  pylorus  by  the 
YV.  mesenteriece  and  the  V.  g  astro -splenica  is  called  the  Yena 
portce.  It  passes  to  the  liver  parallel  with  the  ductus  cTioledoclius 
communis  (§  746  [3]),  and  receives  the  follov^ing  branches  when 
they  do  not  empty  into  any  of  the  preceding : — 

§  952.  V.  pancreatico-duodenalis,  az. — Coming  from  the  pancreas  and  the  duode- 
num.    This  vessel  empties  into  the  F.  portcn  on  the  dorso-dextral  side  of  the  pylorus. 

§  953.  V.  gastro-epiploica.  az. — This  comes  from  the  pyloric  part  of  the  great  curva- 
ture of  the  stomach  and  the  dorsal  fold  of  the  great  omentum.  It  empties  into  the  V- 
portm  opposite  the  pylorus. 

§  954,  V.  coronaria  ventriculi,  az, — As  the  name  indicates,  this  comes  from  the  lesser 
curvature  of  the  stomach.  It  empties  into  the  V.  port<3  somewhat  nearer  the  liver  than 
the  preceding.  The  three  branches  just  described  may  all  unite  to  form  a  single  trunk 
before  emptying  into  the  V.  portce. 

Systemic  Abdominal  Veins.    (See  Table,  §  915.) 

§  955.  Postcava  s.  Vena  cava  inferior,  az.  (see  Table,  §  915, 
Fig.  101,  103,  Postcv.,  107,  Pcv.). — Turn  the  stomach  and  intestines 
to  the  left.  The  postcava,  filled  with  blue  plaster,  will  appear  ex- 
tending somewhat  obliquely  caudo-sinistrad  along  the  meson.  Just 
cephalad  of  the  right  kidney  it  pen(*trates  the  liver  and  is  entirely 
surrounded  by  its  substance.  Opposite  the  last  lumbar  vertebra 
the  vessel  usually  becomes  entirely  mesal  in  position  and  reaches 
the  dorsal  side  of  the  aorta  (Fig.  101).  The  vessel  may  divide  oppo- 
site the  kidneys  into  two  nearly  equal  branches,  which  extend 
caudad,  one  on  each  side  of  the  meson. 

§  956.  V.  phrenica  (Fig.  90). — These  pass  mesad  along  the  opposite  halves  of  the  dia- 
phragm, and  open  into  the  postcava  just  as  it  penetrates  the  diaphragm.  Draw  the  liver 
somewhat  caudad,  and  the  vein  may  be  easily  demonstrated  with  the  tracer. 

§  957.  VV.  hepaticae,  nz.  (10-12),  (Fig.  101).— These  convey  the  blood  supplied  to  the 
liver  by  the  V.  portm  and  the  A.  hepatica  into  the  postcava.  They  may  be  demonstrated 
by  tearing  away  the  liver  substance  next  the  postcava.  Their  number  is  variable,  as  the 
lobes  sometimes  give  off  more  than  one  branch  each. 

§  958.  V.  adreno-lumbalis  (Fig.  101,  103,  107).— This  vein  returns  blood  from  the 
adrenal  (§  760),  from  the  M.  psoas  and  the  dorso-lateral  parietes  of  the  abdomen  opposite 
the  kidney.  It  opens  into  the  postcava  just  caudad  of  the  liver,  or  it  may  empty  into  the 
V.  renalis  (§  959).  To  demonstrate  it,  turn  the  stomach  and  intestines  aside,  and  employ 
the  tracer.     The  vein  usually  rests  in  a  groove  on  the  ventral  side  of  the  adrenal  (Fig.  101). 

§  959.  V.  renaUs  (Fig.  101,  V.  rn  ,  103,  V.  rn.,  107,  V.  rn.).— This 
extends  in  nearly  a  straight  line  from  the  kidney  and  empties  into  the 


DIVISIONS    OF    TBE    POSTCAVA,  357 

side  of  the  postcava.  The  left  is  slightly  cephalad  of  the  right,  and 
both  veins  usually  lie  caudad  of  the  corresponding  arteries  (Fig.  103). 
The  left  renal  vein  usually  receives  the  V.  spermatica  and  nearly 
always  contains  a  pair  of  valves  just  centrad  of  the  entrance  of  the 
V.  spermatica.  The  right  may  also  contain  valves,  but  it  rarely 
receives  the  V.  spermatica  dextra.  Both  often  receive  the  Y.  adreno- 
lumhalls.  The  V.  renatis^  like  the  A.  renalis,  may  be  double  (§  969). 
Finally,  when  the  postcava  is  divided  sufficiently  far  cephalad 
(§  962),  the  V.  renalls  may  empty  into  the  corresponding  division 
instead  of  into  the  postcaval  trunk. 

§  960.  V,  spermatica  (male),  ovarii  (female),  (Fig.  101). — The  left  opens  almost  inva- 
riably into  the  left  renal  (§  959),  while  the  right  nearly  always  empties  directly  into  the 
postcava.     Both  are  guarded  by  a  pair  of  valves  about  5  mm.  from  their  mouth. 

The  V.  spermatica  returns  blood  from  the  testis,  and  hence  passes  nearly  longitudinally 
cephalad  through  the  inguinal  ring  (§  768)  to  the  point  where  it  empties.  It  is  very  slen- 
der and  must  be  traced  with  great  care.  The  V.  ovarii  m  much  shorter,  passes  obliquely 
laterad  from  the  ovary,  and  increases  greatly  in  size  during  gestation. 

§  961.  V.  ilio-lumbalis  (Fig.  101). — This  enters  the  postcava  at  right  angles  nearly 
opposite  the  Crista  ilii  (Fig.  51).  It  returns  blood  from  the  free  or  ventral  surface  of  the 
muscles  in  this  region. 

Divisions  of  the  Postcava. — Usually  the  postcava  is  a  single 
median  vessel  until  it  reaches  a  point  opposite  the  junction  of  the 
6th  and  7th  lumbar  vertebrse.  Here  it  lies  between  the  aorta  and 
the  spinal  column ;  hence  the  aorta  should  be  removed.  But  this 
part  of  the  dissection  should  be  deferred  until  the  arteries  have 
been  studied  (§  965). 

§  962.  Branches : — V.  iliaca  communis  (Fig.  101,  A). — The  post- 
cava in  the  cat  is  formed  by  two  equal  trunks  opposite  the  junction 
of  the  6th  and  7th  lumbar  vertebrse.  Each  trunk  is  one  of  the  com- 
mon iliac  veins.  Sometimes  (once  in  about  ten  cases)  the  postcava 
divides  into  the  common  iliacs  much  farther  cephalad,  rarely  even 
cephalad  of  the  kidneys.  In  such  cases  the  postcava  is  on  the  ven- 
tral or  lateral  aspect  of  the  aorta,  never  on  its  dorsal  side. 

§  963.  V.  iliaca  externa  (Fig.  101). — This  large  vessel  comes 
from  the  leg,  passing  into  the  abdomen  dorsad  of  Poupart's  liga- 
ment (Fig.  39).  It  unites  with  the  following  (§  964)  to  form  the  V. 
iliaca  communis.  The  vein  should  be  traced  peripherad  upon  the 
meros.  Just  as  it  enters  the  abdomen  there  is  a  pair  of  valves  that 
usually  stop  the  plaster  injection  completely.  The  valves  may  be 
easily  demonstrated  by  slitting  the  vein  longitudinally  and  then 
blowing  peripherad  with  the  blow-pipe  (Fig.  102,  B,  C,  §  130).     This 


358  ANATOMICAL    TECHNOLOGY. 

demonstration  will  be  especially  satisfactory  if  the  vein  is  immersed 
in  water. 

§  964.  V.  iliaca  interna  (Fig.  101,  A).— This  returns  blood  from 
the  pelvis,  the  hip  and  the  thigh,  etc.  The  main  trunk  of  this  veui 
is  formed  by  branches  within  the  body  cavity.  It  unites  with  the 
preceding  to  form  the  F.  iliaca  communis.  The  branches  of  this 
trunk  are  so  well  supplied  with  valves  that  they  are  rarely  injected 
with  plaster. 

Aorta  Abdominalis.    (Fig.  101,  103,  107  ;  see  Table,  §  917.) 

§  965.  Turn  the  stomach  and  intestines  to  the  right,  press  upon 
the  median  line  against  the  spinal  column,  and  the  injected  aorta 
will  be  felt.  It  may  be  exposed  by  tearing  away  the  peritoneum 
with  a  tracer.  Commence  at  a  point  just  caudad  of  the  diaphragm, 
expose  the  aorta,  and  note  the  following  branches  and  their  anas- 
tomoses : — 

§  966.  A  coeliaca— Coeliac  axis,  az.  (Fig.  101,  103,  107).— As  the 
aorta  enters  the  abdomen — sometimes  just  before — there  is  given  off 
a  large  trunk,  the  coeliac  axis,  which  extends  nearly  ventrad.  Tear 
away  the  peritoneum  and  connective  tissue  covering  the  vessel,  and 
note  the  following  branches  and  their  distribution : — 

(A)  A.  phrenica  s.  A.  diaphragmatica. — This  artery  is  some- 
times given  off  from  the  cephalic  side  of  the  coeliac  axis  near  its 
origin  from  the  aorta.  More  frequently  it  arises  from  the  A.  adre- 
no-lumbalis  (§  968).  It  soon  divides  into  two  branches  and  is 
distributed  to  the  diaphragm. 

(B)  A.  hepatica,  az. — Turn  the  liver  cephalad  and  draw  the 
stomach  sinistro-caudad.  Tear  away  with  the  tracer  the  peritoneum 
from  the  lesser  curvature  of  the  stomach,  and  the  coeliac  axis  will 
appear.  A  large  branch — A.  hepatica — will  be  seen  arising  from  the 
coeliac  axis,  and  extending  dextro- ventrad  toward  the  liver.  Trace 
it  by  tearing  away  the  peritoneum  and  connective  tissue  with  the 
tracer.    Nearly  opposite  the  pylorus  it  divides  into  three  trunks : — 

(a)  A.  hepatica,  continuing  to  the  liver  and  sending  branches  to  each  of  the  lobes. 

(b)  A.  cystica,  to  the  cholecyst  (Fig.  79). 

(c).  A.  gastro-duodenalis.— This  is  on  the  dorsal  side  of  the  pylorus.  It  furnishes  three 
named  branches  : — 

(1)  A.  pylorica,  extending  from  about  opposite  the  pylorus  along  the  lesser  curvature 
of  the  stomach,  and  finally  anastomosing  with  the  A.  coronaria  ventriculi.  The  A.  pplor- 
ica  sometimes  arises  directly  from  the  A.  hepatica,  as  in  man, 

(2)  A.  gastro-epiploica  dextra.— This,  like  the  preceding  and  following,  passes  dorsad 


BRANCHES    OF    THE    AORTA    ABDOMINALIS.  359 

of  the  pylorus  ;  then  it  extends  along  the  greater  curvature  of  the  stomach  in  the  ventral 
fold  of  the  great  omentum  near  its  attachment  to  the  stomach.  It  anastomoses  with  a 
branch  from  the  spleen  [gastro  epiploica  sinistra  f) 

(3)  A.  pancreatico-duodenalis  siqwrior. — This  passes  along  the  dorsal  side  of  the  pylo- 
rus, then  to  the  left  of  the  duodenum.  It  finally  anastomoses  with  the  pancreatico-duode- 
nalis  inferior  (.Fig.  81). 

(D)  A.  coronaria  ventriculi,  az. — This  branch  arises  from  the  coeliac  axis  only  slightly 
peripherad  of  the  A.  hepatica,  and  is  distributed  to  the  lesser  curvature  of  the  stomach. 
One  of  its  larger  branches  anastomcses  with  the  A.  pylorica  (§  966,  [1]). 

(E)  AA.  ventriculi  dorsales  (Ohauveau,  A,  559).— There  are  usually  two  of  these. 
They  pass  directly  to  the  dorso-sinistral  part  of  the  stomach.     Their  homology  is  doubtful. 

(F)  A.  splenica,  az. — This  is  the  largest  branch  of  the  coeliac  axis,  and  seems  to  be  a 
continuation  of  it.  It  passes  to  the  spleen,  but  before  reaching  that  organ  divides  into 
two  nearly  equal  branches,  one  going  to  each  extremity. 

The  spleen  is  sometimes  double,  and  in  such  a  case  each  part  is  supplied  by  one  of  the 
branches  just  mentioned. 

Numerous  small  branches  pass  from  the  A.  splenica  to  the  pancreas  and  to  the  stomach. 
One  branch  passes  dextrad  in  the  ventral  fold  of  the  great  omentum  to  anastomose  with 
the  A.  gastro-epiploica  dextra  {§  966,  [3]).  This  may  be  the  homologue  of  the  A.  gastro- 
epiploica  sinistra  of  man.  It  is  small,  and  only  rarely  is  the  anastomosis  shown  with  the 
ordinary  plaster  injection.  In  fresh  specimens  the  artery  wiU  contain  sufBcient  blood  to 
enable  one  to  trace  it.     It  is  of  course  easily  filled  with  a  fine  injecting  mass  (§  1450) 

§  967.  A.  mesenterica  superior — Superior  mesenteric  artery,  az. 
(Fig.  101,  103,  107).— Turn  the  stomach  and  intestines  to  the  right. 
The  artery  arises  about  2  cm.  caudad  of  the  A.  cceliaca.  Expose  it 
fully  by  tearing  away  the  peritoneum  and  nerves  covering  it.  Use 
the  tracer,  and  the  scissors  occasionally  if  necessary.  Observe  the 
following  branches  and  their  connections  and  distribution : — 

(A)  A.  pancreatico-duodenalis  inferior  (Fig.  81  [10]). — ^This  passes  obliquely  cephalad 
to  the  duodenal  pancreas  and  anastomoses  with  the  A.  pancreatico-duodenalis  superior. 

(B)  A.  colica  media. — This  branch  is  of  considerable  size.  It  passes  to  the  large 
intestine  and  sends  branches  cephalad  and  caudad.  The  cephalic  branch  anastomoses 
with  the  A.  colica  dextra  (C)  or,  if  that  is  absent,  with  the  A,  ileo-colica.  The  caudal 
branch  anastomoses  with  the  A.  colica  sinistra  (§  971,  A). 

(C)  A.  colica  dextra. — This  is  often  absent  in  the  cat.  When  present  it  passes  to 
the  large  intestine,  and  anastomoses  with  both  (B)  and  (D). 

(D)  A.  ileo-colica. — This  is  a  large  branch,  extending  directly  to  the  caecum.  It  sends 
branches  caudad  to  the  large  intestine,  where  they  anastomose  with  (B)  or  (C),  and  others 
cephalad  to  the  ileum,  where  they  anastomose  with  the  Rami  intestini  tenuis. 

(E)  Rami  intestini  tenuis. — These  are  the  branches  into  which  the  A.  mesenterica 
superior  finally  breaks  up,  and,  as  the  name  indicates,  they  are  distributed  to  the  small 
intestine. 

§  968.  A.  adreno-lumbalis  (Fig.  101,  103, 107).— This  artery  arises  from  the  side  of 
the  aorta,  just  caudad  of  the  origin  of  the  A.  mesenterica  superior  (§  967).  It  passes 
directly  laterad,  giving  off  the  following  branches :  (A)  the  A.  adrenalis  to  the  adrenal, 
and  (B)  the  A.  phrenica  to  the  diaphragm.     The  artery  rests  on  the  free  or  ventral  surface 


360  ANATOMICAL    TECHNOLOGY. 

of  the  M.  psoas  ;  it  is,  however,  partly  covered  by  the  adrenal  and  the  cephalic  end  of  the 
kidney.  It  will  be  necessary  to  remove  the  fat  and  connective  tissue  with  great  care  from 
the  adrenal  and  phrenic  arteries,  and  it  may  be  desirable  to  use  the  forceps  and  scissors  to 
remove  tough  connective  tissue  and  nerves.  As  was  stated  above,  the  A.  phrenica  may  be 
supplied  by  the  cceliac  axis  (§  966).  The  left  A.  adreno-lumbalis  much  more  often  sup- 
plies an  A.  phrenica  than  the  right.  The  left  and  its  branches  are  more  easily  demon- 
strated than  the  right. 

§  969.  A.  renalis  (Fig.  101,  103,  107).— The  renal  artery  arises 
from  the  side  of  the  aorta  like  the  preceding,  and  passes  nearly  lat- 
erad  to  enter  the  hilum  of  the  kidney.  It  usually  gives  from  its 
ventral  surface  a  small  branch  to  the  adrenal,  and  often  one  to  the 
ureter.  The  renal  artery  is  covered  on  its  ventral  surfa9e  by  the 
Y.  renalis ;  hence,  to  obtain  a  good  view  of  the  artery,  the  vein 
must  be  removed  or  drawn  aside.  Employ  the  tracer,  working  care- 
fully in  order  that  the  branches  named  above  may  not  be  broken. 

The  A.  renalis  usually  divides  into  two  nearly  equal  branches 
about  1  cm.  from  the  kidney,  and  one  branch  goes  to  each  side  of 
the  renal  pelvis  ;  it  is  sometimes  double  (Fig.  103). 

§  970.  A.  spermatica  (male),  ovarii  (female),  (Fig.  101). — This  arises  from  the  ven- 
tral surface  of  the  aorta  1-2  cm.  caudad  of  the  A.  renalis.  It  passes  somewhat  obliquely 
caudad,  supplying  the  ovary  in  the  female  and  forming  part  of  tlie  spermatic  cord  in 
the  male. 

Expose  it  by  turning  the  intestines  to  the  right ;  then  very  carefully  tear  away  the 
peritoneum  covering'  the  aorta.  As  the  artery  is  only  about  1  mm.  in  diameter,  great  care 
is  necessary  in  the  dissection  ;  probably  it  will  be  necessary  to  employ  the  forceps  and 
scissors  as  well  as  the  tracer.     In  the  female  the  artery  is  much  convoluted  ;  see  §  960. 

§  971.  A.  mesenterica  inferior,  az.  (Fig.  101,  103,  107).— Th( 
artery  arises  from  the  ventral  surface  of  the  aorta  about  opposil 
the  iliac  crest  (Fig.  51).     It  passes  nearly  ventrad. 

Turn  the  large  intestine  to  the  right,  and  with  the  tracer  follow 
it.     Near  the  large  intestine  it  divides  into  two  branches : — 

(A)  A.  colica  sinistra,  which  extends  cephalad  along  the  large 
intestine  and  anastomoses  with  the  A.  colica  media  (§  967,  B). 

(B)  A.  h  hemorrhoid  alls  superior.     This  passes  caudad  along  th< 
large  intestine  and  anastomoses  with  the  hsemorrhoidalis  media  froi 
the  A.  iliaca  interna. 

§  972.  A.  ilio-lumbalis  (Fig.  101).— This  artery  arises  from  the  side  of  the  aori 
slightly  caudad  of  the  origin  of  the  preceding  (§  971),  and  passes  laterad  over  the  ventrs 
wall  of  the  M.  psoas,  and  to  other  muscles  over  and  near  the  Ilium.  It  is  comparabh 
with  the  A.  adreno-lumhalis  (§  968).  To  demonstrate  it,  turn  the  large  intestine  to  the  rightj 
and  tear  away  the  peritoneum  with  a  tracer.  As  it  is  the  only  artery  passing  laterad  ii 
this  region,  it  cannot  be  mistaken. 


ILIAC    ARTERIES.  361 

% 

§  973.  Divisions  cf  the  Aorta  abdominalis  (Fig.  101,  B). — Expo- 
sure and  Dissection. — Draw  the  urocystis  (Fig.  101)  caudo-ven- 
trad ;  press  the  contents  of  the  rectum  cephalad  ;  doubly  ligate  and 
cut  it  opposite  the  neck  of  the  urocystis.  Cut  the  mesocolon 
(§  726)  and  mesentery  near  their  attachment  to  the  intestine  as  far 
cephalad  as  the  duodenum  ;  then  cut  the  small  intestine  at  the  cau- 
dal end  of  the  duodenum,  and  throw  the  intestines  away.  If  the 
remaining  part  of  tlie  rectum  is  washed  out  with  a  solution  of  ferric 
sulphate  (copperas)  by  introducing  the  canula  of  the  syringe  into 
the  anus,  the  unpleasant  odor  will  be  avoided.  If  the  urocystis 
contains  urine,  it  should  be  pressed  out  through  the  urethra,  or  a 
slit  may  be  cut  in  it. 

In  demonstrating  the  vessels,  employ  the  forceps  and  tracer 
mostly ;  but  use  the  scissors  when  it  is  necessary  to  remove  any 
tough  masses. 

(A)  A.  iliaca  externa  (Fig.  101,  B). — This  passes  obliquely  cau- 
dad,  penetrates  the  abdominal  wall  dorsad  of  Pouparfs  ligamenty 
and  reaches  the  cephalic  side  of  the  meros  where  it  is  called  the 
femoral  artery.  Just  before  the  A.  iliaca  externa  leaves  the  abdo- 
men, it  gives  off  a  large  branch  from  its  mesal  aspect.  This  branch 
supplies  the  A.  epigastrica  (Fig.  101),  then  penetrates  the  abdomen 
near  the  symphysis  pubis,  and  sends  branches  to  the  skin  in  the 
pubic  region,  but  is  mainly  distributed  to  the  muscles  on  the  ce- 
phalic and  ventral  aspects  of  the  proximal  end  of  the  meros.  The 
human  homologue  of  this  artery  has  not  yet  been  satisfactorily 
determined. 

(B)  A.  iliaca  interna  (Fig.  101,  B).— This  arises  from  the  aorta 
about  1  cm.  caudad  of  the  origin  of  the  preceding.  It  passes 
obliquely  caudad  within  the  pelvis  and  dorsad  of  the  pubis.  A 
short  distance  from  its  origin  the  A.  riesicalis  superior  (Fig.  101) 
is  given  off  from  its  ventral  surface.  This  small  vessel  is  the  rem- 
nant of  the  A.  Jiypogastrica  of  the  foetus.  It  occasionally  arises 
from  the  aorta. 

The  A.  iliaca  interna  supplies  most  of  the  pelvic  viscera  entirely  and  furnishes  part 
of  the  hlood  supply  to  the  innominate  and  moral  regions. 

(C)  A,  sacra  media,  az.  (Fig.  101,  B).— The  aorta  is  continued  to  the  tail  by  this  small 
raesal  artery,  which  passes  through  the  arches  formed  by  the  chevron  bones  (§  465). 

It  will  be  seen  by  comparing  the  figure  of  the  cat  with  that  of  man  (Quain,  A,  I,  281, 
Gray,  A,  324),  that  in  the  cat  there  is  no  common  iliac  as  in  man,  but  each  iliac  is  a 
branch  of  the  aorta. 


362  ANATOMICAL    TECHNOLOGY. 

§  974.  AA.  lumbales  (6  pairs). — The  lumbar  arteries  arise  from  the  dorsal  side  of  the 
aorta  opposite  the  intervertebral  fibro-cartilages.  They  extend  directly  dorsad  for  a  short 
distance,  and  then  turn  laterad  to  be  distributed  to  the  ental  or  attached  surface  of  the 
muscles  on  the  ventral  and  lateral  aspects  of  the  spinal  column.  A  small  branch  usually 
enters  the  intervertebral  foramen  to  supply  the  myelon. 

§  975.  Demonstration  of  the  AA.  lumhales. — Turn  the  stomach 
to  the  right,  cut  the  left  renal  vessels  and  remove  the  left  kidney 
and  the  left  half  of  the  diaphragm.  Draw  the  aorta  dextrad. 
Commence  opposite  the  last  rib,  and  with  the  forceps  and  tracer 
clear  away  the  fat  and  connective  tissue  on  the  dorsal  and  sinistral 
aspects  of  the  aorta.  From  the  great  caudal  projection  of  the  dor- 
sal part  of  the  diaphragm,  the  1st,  2d,  and  sometimes  3d,  pairs  of 
AA.  lumbales  are  given  off  within  the  thorax  ;  hence  the  necessity 
of  removing  the  diaphragm.  The  last  pair  is  given  off  by  the  aorta 
just  caudad  of  the  origin  of  the  A.  iliaca  externa.  Tear  and  cut 
away  carefully  the  muscles  and  connective  tissue,  and  trace  the  2d 
or  3d  A.  lumbalis  and  its  distribution  as  described  above  (§  974). 

STRUCTURE   OF   THE   HEART  AND  BLOOD   VESSELS. 

§  976.  Obvious  Structure  of  the  Heart.— (A)  The  heart  is  covered  by  a  serous  mem- 
hrane — the  ental  (inner)  layer  of  the  pericardium  (§  910). 

(B)  Its  main  substance  is  composed  of  muscle,  apparently  but  not  really  like  the  ordi- 
nary voluntary  muscles.     Compare  §§  704  and  705. 

The  arrangement  of  muscular  fasciculi  in  the  auricles  seems  to  be  comparatively  simple, 
namely,  in  two  layers,  of  which  the  ectal  have  a  circular  and  the  ental  a  longitudinal 
direction  (Strieker,  A,  183).  But  in  the  ventricular  icalls  the  arrangement  is  very  complex 
(Quain,  A,  I,  Fig.  179).  According  to  Pettigrew  (A,  194),  there  are  no  less  than  seven, 
more  or  less  distinct  layers,  the  fibers  of  which  vary  in  direction  from  nearly  circular  to 
nearly  longitudinal,  with  several  degrees  of  obliquity.  The  author  just  named  recom- 
mends (p.  193,  note  2)  that  for  the  study  of  the  layers,  the  cavities  should  be  filled  with 
bran  and  the  organ  then  boiled  for  from  4-10  hours,  according  to  size,  and  kept  in  alcohol 
for  a  fortnight  before  dissecting. 

(C)  The  cavities  (Fig.  92)  are  lined  by  a  firm  serous  membrane — the  endocardium. 

(D)  Valves  and  chordm  tendinem  (§§  864.  881-884). 

§  977.  Microscopic  Structure. — (A)  The  serous  covering  and  lining  of  the  heart  has 
the  structure  belonging  to  serous  membranes  generally  (§  730). 

(B)  "The  muscular  fibers  of  the  heart  differ  remarkably  from  those  of  involuntary 
muscular  organs  in  general,  inasmuch  as  they  present  transverse  stri(e.  The  strise,  how- 
ever, are  less  strongly  marked  and  less  regular,  and  the  fibers  are  smaller  in  diameter  than 
in  the  voluntary  muscles  (§  705).  They  differ  also  from  these  in  being  made  up  of  quad- 
rangular cells  joined  end  to  end,  and  often  presenting  a  branched  or  forked  appearance 
near  one  extremity.  Each  cell  has  commonly  a  single  clear  oval  nucleus  situated  near 
the  center ;  occasionally  two  nuclei  are  seen.  The  cell  substance  is  faintly  striated  lon- 
gitudinally as  well  as  transversely  ;  it  presents  no  indication  of  an  investing  membrane  or 
sarcolemma.     As  stated  by  Strieker,  however  (A,  182)  the  '  cells  of  muscles,  like  all  other 


THORACIC    DUCTS.  363 

naked  cells,  must  present  a  peripheral  investment  ; '  that  is,  like  all  cells  which  form 
part  of  a  complex,  compact  structure,  and  do  not  simply  float  free  in  a  liquid  as  do  the 
leucocytes  in  the  blood.  The  muscular  fibers  of  the  heart  freely  divide  and  anastomose, 
the  junction  with  neighboring  fibers  being  effected  by  the  medium  of  the  cell -offsets 
above  noticed."     Strieker,  A,  179  ;  Quain,  A,  II,  119,  240,  261. 

§  978.  Arteriae. — Their  obvious  structure  is  that  of  smooth-bored,  thick-walled  tubes 
which  retain  their  form  when  cut.     They  are  elastic  and  flexible. 

§  979.  Microscopic  Structure. — They  are  composed  of  three  well-defined  coats : — (A) 
Ectal  or  outside  coat,  tunica  adventitia,  of  rather  loose  elastic  and  white  connective  tissue, 
with  a  general  longitudinal  direction.  (B)  Intermediate  or  middle  coat,  composed  of  elas- 
tic and  white  connective  tissue  and  circularly  arranged  muscular  fibers.  (C)  Ental  or 
inner  coat,  composed  of  elastic  tissue  covered  by  endothelium  on  its  free  surface. 

i^  980.  Muscular  and  Elastic  Types  of  Arteries. — Ranvier  and  others  have  divided  the 
arteries  into  the  two  classes  jast  named,  from  the  preponderance  of  elastic  tissue  or  of  mus- 
cular fibers  in  the  middle  coat.  The  larger  arteries,  like  the  carotids,  the  axillary  and  the 
aorta,  contain  very  little  muscular  tissue,  and  hence  they  belong  to  the  elastic  type.  The 
arteries  of  the  limbs  and  the  smaller  arteries  generally  contain  a  large  amount  of  muscu- 
lar tissue  in  their  middle  coat,  and  hence  represent  the  muscular  type. 

§  981.  Venae. — The  ohmous  structure  of  these  is  the  same  as  that  of  the  arteries,  but 
the  walls  are  thin,  so  that  they  collapse  when  cut. 

§  982.  Microscopic  Structure. — There  are  three  coats  as  with  the  arteries.  The  white 
connective  tissue  is  more  abundant  in  the  middle  coat.  Smooth  muscle  is  often  present  la 
the  ectal  coat  of  some  large  veins,  like  the  Vena  cava,  while  it  is  entirely  wanting  in 
others,  as  in  most  of  those  of  the  brain  and  pia  mater ;  Quain,  A,  II,  173. 

§  983.  Capillaries. — "  The  wall  of  the  capillaries  proper  is  formed  entirely  of  a  simple 
epithelioid  layer,  composed  of  flattened  lanceolate  cells  joined  edge  to  edge,  and  continuous 
with  the  corresponding  layer  which  lines  the  arteries  and  veins."     Quain,  A,  II,  177. 

§  984.  The  structure  of  the  lymphatic  vessels  very  closely  resembles  that  of  the  blood 
vessels.     Quain,  A,  II,  186. 

THORACIC  DUCTS  AND  LYMPHATIC  VESSELS. 

References.— Quain,  A,  I,  504 ;  Gray,  A,  589  ;  Cuvier,  A,  VI,  60 ;  Gegenbaur  (Lan- 
kester),  A,  599  ;  Hyrtl,  A,  750  ;  Bernard,  A,  253  ;  Leyh,  A,  656  ;  Owen,  A,  III,  511  ; 
Milne-Edwards,  A,  IV,  503  ;  Chauveau,  A,  675 ;    Chauveau  (Fleming),  A,  634 ;   Gurlt, 

4^,  681. 

Instruments  and  materials  the  same  as  for  the  blood  vessels 

(§  912). 

§  985.  Specimen,  Preparation,  Posture  and  Dissection. — Employ  a  young,  but 
especially  a  lean  cat.  Feed  the  cat  with  milk  or  fat  meat,  and  after  two  hours  kill  with 
chloroform.  Inject  the  femoral  artery  with  red  starch  (Fig.  39,  §  352  and  leaflet  between 
pp.  140, 141),  or  open  the  abdomen  as  for  abdominal  viscera  (§  710)  and  inject  the  aorta  just 
caudad  of  the  origin  of  the  inferior  mesenteric  artery  (Fig.  101).  After  the  arterial  injec- 
tion is  made  and  the  abdominal  cavity  opened,  draw  the  intestines  to  the  right  and  a  large 
lacteal  vessel  will  be  seen  passing  from  the  large  mesenteric  glands  near  the  caecum,  dorso- 
cephalad  toward  the  cephalic  end  of  the  left  kidney.  Where  this  lacteal  vessel  crosses 
the  superior  mesenteric  vein  (Fig.  103),  or  slightly  centrad  of  that  point,  remove  one  wall 


364  ANATOMICAL     TECHNOLOGY. 

of  the  mesentery  (§  725)  by  tearing  it  away  with  the  tracer  along  the  sides  of  the  vessel 
rather  than  directly  over  it.  When  the  vessel  is  exposed  cut  a  V-shaped  incision  with 
pointed  scissors,  and  insert  a  canula — but  it  need  not  be  tied  in.  Simple  pressure  with 
the  thumb  and  index  during  the  injection  will  prevent  regurgitation,  and  the  valves 
prevent  the  escape  of  the  mass  after  the  injection  is  finished.  Fill  the  canula  with 
water,  and  then  inject  yellow  starch  (§  345,  E.  pp.  139-140).  The  pressure  must  be  very 
slight ;  and  if  the  kidney  and  other  tissues  covering  the  receptaculum  chyli  (Fig.  103) 
are  gently  compressed  during  the  injection,  success  will  be  more  certain.  In  case  the 
large  lacteal  is  not  filled  with  chyle,  it  may  be  filled  with  Berlin  blue  by  injecting  into 
one  of  the  mesenteric  glands  near  the  caecum,  as  described  in  (§  992  B).  Open  the  ab- 
domen as  for  the  abdominal  viscera  (§  710),  and  the  thorax  as  for  the  blood  vessels 
(§  918),  except  that  the  left  side  should  be  cut  as  well  as  the  right,  and  the  longitudinal 
incisions  carried  caudad  till  they  reach  the  free  edge  of  the  abdominal  flaps.  Cut  the 
diaphragm  next  the  ventral  wall,  and  remove  the  ventral  wall  with  great  care  so  as  to 
avoid  wounding  the  veins  or  arteries.  With  nippers  (Fig.  11),  cut  the  left  ribs,  except  the 
first,  about  3  cm.  from  their  heads.     Turn  the  free  edge  of  the  thoracic  wall  to  the  left. 

§  986.  Vasa  chylifera,  Lacteals. — Turn  tlie  omentum  majus 
cephalad  and  lift  the  intestines.  Look  at  the  mesentery,  and  the 
lacteal  vessels  will  be  seen  as  whitish  or  yellowish  lines  extending 
dorsad  from  the  intestine  and  nearly  parallel  with  the  blood  ves- 
sels. 

Dorsad  of  the  csecum  the  lacteal  crosses  obliquely  the  superior 
mesenteric  vein  (Fig.  103,  V.  m.  s.),  and  extends  dorsad  nearly 
parallel  with  the  superior  mesenteric  artery  (Fig.  103,  A.  m.  s.). 
Attempt  to  force  the  contained  chyle  toward  the  peripliery,  and  the 
beaded  appearance  shown  in  Fig.  103  will  result.  This  is  due  to 
the  valves^  which  are  similar  in  form  and  function  to  those  in  the 
veins  (Fig.  102,  B.  c,  §  963). 

§  987.  Receptaculum  chyli,  az.  (Fig.  103). — This  is  a  fusiform 
enlargement  at  the  caudal  end  of  the  left  thoracic  duct,  into  which 
empty  the  lacteals  or  vasa  chylifera  from  the  alimentary  canal,  and 
the  lymphatics  from  the  caudal  half  of  the  body  (§  992). 

Exposure. — Cut  the  peritoneum  along  the  abdominal  wall  from 
the  caudal  end  of  the  kidney  to  the  diaphragm.  Reflect  the  peri- 
toneum and  kidney  mesad,  and  the  receptaculum  will  appear  as 
a  fusiform  yellowish  sac  on  the  dorso-sinistral  side  of  the  aorta, 
extending  from  a  point  about  opposite  the  hilum  of  the  kidney  to 
the  hiatus  aorticus  in  the  diaphragm  (Fig.  90). 

§  988.  Ductus  thoracicus  sinister  (Fig.  103).— The  left  thoracic 
duct  is  the  common  trunk  which  receives  the  lymphatics  of  the 
entire  caudal  half  of  the  body,  including  those  of  the  alimentary 
canal — the  lacteals  or  vasa  chylifera — and  those  of  the  left  side  of 
the  head,  face,  neck  and  thorax.     It  pours  its  contents — lymph  or, 


THE    EIGHT    THORACIC    DUCT.  S65 

during  digestion,  mixed  lymph  and  cliyle— into  the  V.  jugalaris 
externa. 

The  duct  almost  invariably  divides  into  two  or  more  trunks  near 
the  middle  of  its  course.  After  extending  for  a  few  centimeters  as  a 
double  or  triple  duct,  it  may  unite  and  then  divide  again  before 
emptying  into  the  vein  (Fig.  103j.  See  Colin,  A,  article  Tlioracic 
Duct^  for  variations  in  the  domestic  animals. 

§  989.  Dissection. — Slit  the  diaphragm  ventrad  from  the  liiatus 
aorticus  (Fig.  90),  and  turn  the  two  crura  or  pillars  of  the  dia- 
phragm asida  as  shown  in  Fig.  103,  Cms  dphrg.  Turn  the  heart 
and  lungs  to  the  right,  and,  if  the  cat  is  lean,  the  thoracic  duct  will 
be  seen  on  the  dorso-sinistral  side  of  the  aorta,  as  a  continuation 
cephalad  of  the  receptaculum  (Fig.  103).  Cephalad  of  the  heart  it 
rests  on  the  ventral  aspect  of  the  A.  subclama  sinistra.  It  finally 
crosses  the  V.  hracliio-eeplialica  sinistra  and,  receiving  the  vasa 
lympTiatica  from  the  head  and  neck,  empties  into  the  V.  jugu- 
laris  externa  near  the  angle  of  union  of  that  vessel  with  the  V. 
subclama.  As  a  rule,  however,  the  thoracic  duct  opens  into  the 
vein  in  two  places,  as  shown  in  Fig.  103.  Both  branches  of  the 
divided  thoracic  duct  may  receive  a  lymphatic  vessel  from  the  head 
and  neck.  In  isolating  the  duct,  it  is  necessary  to  proceed  with 
great  care.  The  tracer  must  be  employed  sparingly.  The  pleura 
and  connective  tissue  are  most  safely  removed  piecemeal  with  scis- 
sors and  tine  forceps,  as  directed  for  exposing  the  nerves  and  sali- 
vary glands  of  the  face  (§  777).  It  is  especially  difficult  to  isolate 
the  duct  in  its  cephalic  third,  as  it  is  usually  double  or  triple,  and 
each  part  therefore  correspondingly  small  (Fig.  103,  A). 

The  first  rib  must  now  be  carefully  cut  and  removed.  The 
largest  of  the  vasa  lymphatica  in  the  neck  rests  on  the  longus  colli 
muscle  entad  of  and  parallel  with  the  carotid  artery. 

§  990.  Ductus  thoracicus  dexter. — The  right  thoracic  duct  or 
great  lymphatic  vein  is  the  large  lymphatic  trunk  into  which  empty 
the  vasa  lymphatica  of  the  right  side,  of  the  thorax,  of  the  head  and 
of  the  neck.  It  opens  into  the  right  V.  jugular  is  externa  in  the 
same  way  as  the  left  empties  into  the  left  V.  jugularis  externa. 

%  991.  Exposure  and  Dissection. — Employ  the  same  specimen 
that  was  used  for  the  left  duct,  make  an  incision  on  the  right  along 
the  neck,  and  expose  the  V.  jugularis  externa  to  its  junction  with 
the  y.  subclavia.  Bo  this  very  carefully.  The  vasa  chylifera  will 
be  seen  dorsad  of  the  carotid,  entering  the  veins  as  described  after 


366 


ANATOMICAL    TECHNOLOGY. 


PiQ.  103.—  The  Left  Thoracic  Duct,  Sinistral  View  ;   x  .5.    A.   Termination  of 

THE  Thoracic  Duct  ;   x  3. 


THORACIC    DUCTS.  367 

uniting  with  the  duct  from  the  thorax.  The  lymph  in  these  vessels 
will  be  pale,  and  hence  they  must  be  looked  for  with  care.  They 
may  usually  be  recognized  from  their  characteristic  moniliform 
appearance  (Fig.  103) ;  they  may  be  injected  (§  992,  A). 

LYMPHATIC   VESSELS. 

The  lymiDliatics,  like  the  veins,  contain  many  valves,  making  it  impossible  to  inject 
from  a  large  trunk  peripherad,  as  with  the  arteries.  The  vessels  may  be  filled,  however, 
by  the  puncture  method  of  Ludwig,  which  consists  simply  in  thrusting  a  sharp  pointed 
canula  into  the  tissues  and  forcinop  Berlin  blue  through  the  canula  with  a  syringe. 

§  992.  Lymphatics  of  the  Arms  and  Legs. — To  inject  these 
prepare  a  glass  canula  (Fig.  ^,  leaving  the  point  sharp.  Fill  the 
syringe  with  Berlin  blue  and  connect  it  by  means  of  a  rubber  tube 
to  the  canula.  Then  with  the  tracer  perforate  the  skin  covering  the 
pad  in  the  middle  of  the  hand  or  foot  of  a  cat  just  killed  (see  §§  189- 
194),  and  insert  the  canula.  Push  it  into  the  tissues  slightly  and 
force  the  piston  slowly  down ;  at  the  same  time  compress  the  foot 
and  press  upon  the  limb  in  such  a  way  as  to  facilitate  the  flow  of 
the  mass  centrad.  It  is  well  to  insert  the  canula  into  all  the  pads 
on  the  ventral  surface  of  the  manus  or  pes.  It  requires  some  time 
to  All  the  vessels  well.  In  the  cat  the  larger  trunks  follow  the  veins. 
If  the  leg  is  pressed  as  directed  and  the  injection  long  enough  con- 
tinued (15-30  minutes),  the  thoracic  duct  may  be  filled.     ..  , 

§  992,  A.  Lymphatics  of  the  Neck  and  Face. — To  inject  these  employ  a  similar  or 
the  same  specimen,  and  insert  the  canula  in  the  naked  place  at  the  end  of  the  snout,  as 
directed  for  the  pad  of  the  foot.  Press  on  the  nose  and  face.  In  this  way  the  lymphatic 
vessels  on  the  face  and  in  the  neck  and  the  lymi)hatic  glands  in  Fig.  87  {01.  lym.)  are  very 
easily  injected. 

§  992,  B.  Injection  of  Lymphatic  Glands. — The  lymphatic  glands  upon  an  injected 
vessel  are  injected,  since  the  vessels  enter  them.  One  may,  however,  inject  the  glands 
directly  and  so  fill  the  efferent  vessels.  This  is  very  easily  done  by  inserting  the  canula  at 
the  peripheral  edge  of  the  gland  and  injecting  centrad.  The  gland  will  first  become  very 
blue  and  then  the  mass  will  appear  in  the  efferent  vessels.     Those  at  the  side  of  the  face 

Iy.  87)  and  the  mesenteric  glands  (§  731)  are  large  and  favorable  for  this  operation. 
If  it  is  desired  to  make  permanent  preparations  of  the  injected  lymphatics,  the  blue 
uld  be  mixed  with  half  its  volume  of  the  blue  gelatin  mass  (§  1450,  Frey,  A). 
For  the  structure  of  the  lymphatic  vessels,  see  §  984. 
Preparation— Fig.    103.— A  cat  was  fed  as  described  above 
(§  985).    Then  the  arteries,  but  not  the  veins,  were  injected,  and  the 
abdomen  and  thorax  were  opened  as  there  described.    The  position 
of  the  large  lacteal  trunk  crossing  the  F.  mesenterica  superior  was 
then  found  as  described,  and  a  V-shaped  incision  made  in  it  with 


368  ANAT03nCAL    TECHNOLOGY. 

scissors  (Fig.  40)  at  the  point  where  it  crosses  the  vein.  A  canula 
was  inserted,  but  not  tied.  The  injecting  mass  w^as  thin  and  colored 
with  chrome  yellow  (§  344,  E).  A  very  gentle  pressure  was  exerted 
in  forcing  down  the  piston  of  the  syringe.  The  canula  was  lightly 
compressed  with  the  lingers  where  it  w^as  inserted  in  the  vessel. 
The  receptaculum  and  duct  were  slightly  compressed,  the  fingers 
being  moved  at  the  same  time  cephalad,  to  facilitate  the  movement 
of  the  injecting  mass>  When  the  duct  seemed  well  filled,  the  can- 
ula was  removed.  After  the  injection  of  the  duct,  the  most  caudal 
part  of  the  postcava  was  opened  to  allow  the  blood  to  escape,  and 
then  loosely  ligatured  centrad  of  the  incision.  Finally,  the  veins 
were  injected  with  blue  plaster  (§  342)  from  the  axillary  vein.  After 
an  hour  the  vasa  cTiylifera,  receptaculum  and  duct  were  carefully 
isolated  as  described  above  (§  989).  The  specimen  was  preserved 
as  directed  (§  286). 

Explanation  of  Fig.  103.— Adrn.,  Corpus  adrenale — The  adrenal  or  suprarenal 
body.  Aorta.  A.  rn.,  A.  renalis — The  renal  artery.  A.  m.  s.,  A.  mesenterica  supe- 
rior— The  superior  mesenteric  artery.  The  lacteal  vessel  which  was  injected  extends  nearly 
parallel  with  this.  A.  c,  A.  cceliaca— The  coeliac  artery  or  axis.  A.  adreno-lumbalis — 
The  adreno-lunibar  artery.  A  A.  costales — The  costal  or  intercostal  arteries.  A.  brcph., 
A.  brachio-cephalica — The  brachio-cephalic  or  innominate  artery.  A.  sbcl.,  sin.,  A. 
subclavia  sinistra — The  left  subclavian  artery.  A.  sbclv.  dext.,  A.  subclavia  dextra — 
The  rit^ht  subclavian  artery.  A.  vert.,  A.  vertebralis — The  vertebral  artery.  A.  incstl. 
sup.,  A.  intercostalis  superior — The  superior  intercostal  artery.  A  A.  sternales — The 
sternal  or  internal  mammary  arteries.  Cardia — The  heart.  C.  1.  az.,  Cavum  lobi  azygi 
(§  810,  Fig,  89).  Colon  et  caecum.  Costae  (14) — Ribs.  In  this  cat  there  were  fourteen 
ribs.  Crus  dphrg.  (diaphragmaticum) — One  of  the  pillars  of  the  diaphragm.  Ductus 
thoracicus  sinistra — The  left  thoracic  duct.  Duod.,  Duodenum.  Glnd.  lym.,  Glandula 
lymphatica — One  of  the  lymphatic  glands.  Several  small  branches  connect  it  with  the 
injected  lacteals.  Humerus — See  Fig.  46.  Ileum — The  part  of  the  small  intestine  next 
the  caecum.  Mesocolon — The  duplicature  of  peritoneum  belonging  to  the  colon.  M. 
psoas.  M.  longus  colli.  M.  serrat.,  M.  serratus  magnus  (§  634).  M.  teres  (§  680). 
M.  latissimus,  M.  latissimus  dorsi  (§  635).  N.  splnch.,  N.  splanchnicus — The  two 
splanchnic  nerves  are  shown  here  (see  Fig.  107).  N.  g.  d.,  N.  gastricus  dorsalis — The 
dorsal  gastric  nerve.  N.  g.  v.,  N.  gastricus  ventralis — The  ventral  gastric  nerve. 
N.  phrn.,  N.  phrenicus— The  left  phrenic  nerve.  N.  sympathicus— The  left  sym- 
patliic  or  sympathetic  nerve.  Omentum  maj us— Epiploon  (§  737).  CEs.,  CEsophagus, 
Postcv.,  Postcava. — The  inferior  or  ascending  vena  cava.  Pancreas.  Recep.  chyli, 
Receptaculum  chyli.  V.  m.  s.,  V.  mesenterica  superior — The  superior  mesenteric  vein. 
V.  sbclv.  sin.,  V.  subclavia  sinistra — The  left  subclavian  vein.  V.  jgl.  ext.,  V.  jugu- 
laris  externa — The  external  jugular  vein. 

Fig.  103,  A. — Termination  of  the  left  thoracic  duct. 

Vena  subclavia  sinistra — The  left  subclavian  vein.  V.  brcph.  sin.,  V.  brachio- 
cephalica  sinistra.  V.  jgl.  ext.,  V.  jugularis  externa — The  external  jugular  vein. 
Vas  lymph,  (lymphaticum)— One  of  the  lymphatic  trunks  from  the  head. 


CHAPTER    IX. 

NEUROLOGY— THE  STUDY  OF  THE  NERVOUS  SYSTEM. 

GENERAL  CONSIDERATIONS — THE  MYELON  (SPINAL  CORD)  AND  ITS  NERVES — THE  BRA- 
CHIAL PLEXUS — THE  VAGUS  NERVE — THE  SYMPATHIC  SYSTEM — THE  RELATIONS  OF 
THE  SYMPATHIC  AND  MYELEN CEPHALIC  (CEREBRO-SPINAL)  SYSTEMS — STRUCTURE 
OF  NERVOUS   MATTER. 

§  993.  General  Considerations.  —  Nerves.  —  Throughout  the 
"body,  distributed  to  all  organs  and  membranes,  there  are  white  cords 
which  are  neither  hollow  like  the  vessels  nor  inextensible  like  the 
tendons,  but  composed  of  a  greater  or  less  number  of  fibers  of  a 
peculiar  structure  (§  1048).  These  cords  are  called  nerves ;  the 
larger  ones  are  also  distinguished  as  trunks,  the  smaller  as  branches, 
the  yet  smaller  as  twigs,  and  the  final  subdivisions  2i^  fibers  or  ter- 
minal  filaments. 


I^lu( 


§  994.  Ganglia. — The  peripheral  ends  of  the  nerves  are  distributed  to  the  various  tis- 
es  constituting  the  muscles,  bones,  viscera,  membranes,  etc.  Their  central  ends,  how- 
ever, are  sooner  or  later  traceable  to  collections  of  cells  (§  1048,  B),  with  which  they  are 
more  or  less  closely  and  directly  connected.  Such  collections  of  cells,  whether  or  not 
intermingled  with  fibers,  are  called  ganglia,  or  said  to  constitute  ganglionic  tissue. 

%  995.  Alba  and  Ginerea. — In  the  ganglia  the  gray  protoplasm  of  the  nerve  cells 
imparts  to  the  mass  a  more  or  less  decided  gray  color.  Hence  the  ganglionic  tissue  is 
commonly  spoken  of  as  the  gray  matter,  or  more  technically  the  (substantia)  cinerea. 

But  although  the  central  (ental)  part  of  each  nerve  fiber  is  a  band  of  gray  protoplasm, 
it  is  in  most  cases  so  completely  covered  by  a  white  substance  {myeline,  medullary  sheath 
or  icMte  substance  of  Schwann),  that  the  prevailing  color  of  the  fibrous  nervous  tissue  is 
>rhite,  and  it  is  commonly  known  as  the  white  substance,  or  more  technically  the  (substan- 
tia) alba. 

%  996.  Primary  Divisions, — The  nerves  and  ganglia  may  be 
conveniently  considered  as  forming  two  great  divisions  w^hich  are 
tolerably  distinct  in  location  and  functions,  but  are  nevertheless 
anatomically  connected  and  physiologically  associated  :  they  are 
the  sympathic  (sympathetic)  and  the  myelencephalic  (cerebro-spinal) 
nervous  systems. 
24 


370  ANAT03nCAL    TECHNOLOGY. 

The  latter  is  more  directly  connected  with  the  sJcin  and  with  the 
skeletal  muscles  which  are  commonly  voluntary. 

The  former  is  cliiefly  distributed  to  the  viscera  and  to  the  vascu- 
lar system^  and  is  regarded  by  some  as  merely  a  dependency  of 
tlie  other. 

§  997.  Centred  and  Peripheral  Portions. — Provisionally  adopting  the  arrangement 
above  indicated  as  at  least  convenient,  each  of  these  two  great  divisions  of  the  nervous 
system  consists  of  a  central  and  a  peripheral  portion.  The  central  portion  of  the  sym- 
pathic  is  a  double  chain  of  ganglia  placed  along  the  ventral  aspect  of  the  columna  ver- 
tebralis,  and  thus  within  the  ventral  or  visceral  somatic  cavity.  Two  pairs  of  these 
ganglia  are  shown  in  Fig.  109,  that  of  the  left  side  displaced  dorsad.  The  peripheral 
part  comprises  the  branches  from  these  ganglia,  witli  plexuses  situated  among  or  upon 
the  viscera  and  vessels,  and  numerous  small  ganglia  in  the  walls  of  the  intestine  and  else- 
where. The  details  of  the  arrangement  of  this  system  will  be  given  in  connection  with 
Fig.  107  and  109,  where  also  will  be  pointed  out  the  existence  of  rami  communicantes 
between  the  sympathic  and  the  cerebro-spinal  systems. 

The  peripheral  part  of  the  cerebro-spinal  system  consists  of  nerves  which  occasionally 
form  plexuses  (Fig.  104,  105),  and  present  ganglia  at  points  to  be  presently  indicated. 

The  central  part  of  the  cerebro-spinal  system  is  lodged  within  the  canalis  neiiralis  s, 
csrebro-spinalis—t\\G  cavities  of  the  cranium  (§  491)  and  vertebral  column  (§  479).     It  is 
continuous  mass  of  alba  and  cinerea.      The  cranial  portion  is  the  encephalon  or  brain, 
and  the  spinal  portion  is  the  myelon  or  spinal  cord.     The  dorsal  aspect  of  the  brain  and 
of  part  of  the  myelon  is  shown  in  Fig.  104. 

§  998.  The  Myelonal  Alba  and  Cinerea. — The  cinerea  of  the  myelon  presents  the  form 
of  a  column  deeply  fluted  on  four  sides,  dorsal,  ventral  and  lateral.  On  a  transection,  the 
appearance  is  approximately  that  of  alerter  H,  the  ends  of  the  two  uprights  being  curved 
laterad.  Hence  these  areas  are  commonly  known  as  the  cornua  or  horns,  two  dorsal  and 
two  ventral. 

The  interspaces  are  occupied  by  the  aWa.  Since,  however,  the  myelon  is  nearly  divided 
into  lateral  halves  by  the  fissures,  dorsal  and  ventral,  what  would  otherwise  be  single  dor- 
sal and  ventral  columns  of  alba  are  double ;  hence  on  each  side  there  is  a  lateral  column 
and  a  dorsal  and  ventral  one.  These  features  are  indicated  upon  Fig.  109  and  112.  The 
general  arrangement  of  alba  and  cinerea  in  the  brain  will  be  described  in  connection 
with  the  structure  of  that  organ  in  Chap.  X. 

§  999,  Motor  and  Sensory  J^erves.— By  means  of  experiments,  it  has  been  ascertained 
that  certain  nerves  mainly  or  exclusively  transmit  sensory  impressions,  made  upon  the 
parts  to  which  their  peripheral  ends  are  distributed,  toward  the  myelencephalon,  that  is, 
centrad  qv  centripetally  ;  while  others  convey  motor  impulses  to  muscles  in  the  opposite 
direction,  peripherad  or  centrifugally. 

§  1000.  Motor  and  Sensory  Boots.— A  nerve,  especially  a  large  trunk,  usually  contains 
some  of  both  sets  of  fibers  ;  but  near  the  junction  of  the  trunks  with  the  myelon,  each 
trunk  divides  into  two  roots,  which  are  attached  to  the  myelon  upon  its  dorsolateral  and 
ventro-lateral  aspects  respectively.  Anatomically,  these  roots  are  dorsal  and  ventral  (an- 
terior and  posterior),  but  physiologically,  they  differ  as  do  certain  of  the  cranial  nerves: 
the  dorsal  ernes  transmit  impressions  centrad,  and  the  ventral  ones  transmit  motor  impulses 
peripherad.  Hence  they  are  commonly  designated  as  the  motor  and  sensory  roots  of  the 
spinal  nerves. 


1 


GENERAL    CONSIDERATIONS,  371 

^  1001.  The  Cranial  Nerves. — As  will  be  shown  in  Chap.  XI,  there  are  reasons  for 
reofardin^  some  at  least  of  the  nerves  which  arise  from  the  brain  as  representing  the  motor 
and  sensory  roots  of  ordinary  myelonal  nerves. 

§  1002,  Functions  of  the  Alba. — So  far  as  known,  the  nerves  and  other  parts  consisting 
wholly  of  the  white  or  fibrous  nervous  tissue  are  simply  capable  of  transmitting  impres- 
sions which  are  made  upon  them  ;  their  office  is  one  of  conduction  only. 

§  1003.  Functions  of  the  Ginerea. — Different  portions  of  the  gray  or  ganglionic  nervous 
tissue  have  been  found  to  act  in  one  or  more  of  the  following  ways : — 

(A)  As  Trophic  Centers. — The  ganglia  upon  the  dorsal  roots  of  the  myelonal  nerve 
trunks  (Fig.  109)  seem  to  preside  in  some  way  over  the  nutrition  of  those  roots,  and  are 
therefore  said  to  have  a  trophic  action.  The  same  may  be  the  case  with  the  ganglia  con- 
stituting the  central  portion  of  the  sympathic  system. 

(B)  As  Centers  of  Automatic  Action. — The  ganglia  in  the  substance  of  the  heart,  and 
perhaps  in  some  other  localities,  appear  to  possess  the  power  of  bringing  about  the  action 
of  the  muscular  fibers  with  which  they  are  connected  independently  of  other  parts, 

(C)  As  Centers  of  Inhibition. — Certain  portions  of  the  cinerea  seem  to  be  able,  either 
automatically  or  otherwise,  to  interfere  with,  check  or  inhibit  the  activity  of  other  parts 
of  the  cinerea. 

(D)  As  Agents  of  the  Will. — Portions  of  the  cortex  cerebri  appear  to  be  immediately 
under  the  influence  of  wUtion,  which  is  unable  to  directly  actuate  other  parts  of  the 
brain  or  of  the  body. 

(E)  As  a  Medium  of  Conduction. — Acting  as  the  agent  of  the  Will,  the  cortical  cinerea 
must  be  capable  of  transmitting  impressions  and  impulses  to  and  from  the  rest  of  the  body. 
Moreover,  there  are  reasons  for  believing  that  the  myelonal  cinerea  does,  or  at  least  may, 
take  a  share  in  the  transmission  of  impressions  and  impulses  between  the  brain  and  the 
body. 

(F)  As  a  Center  of  Beflex  Action. — Many  actions,  especially  those  of  the  viscera  and 
vessels,  are  brought  about  in  an  indirect  way.  An  impression  made  at  the  peripheral 
end  of  a  sensory  nerve  is  transmitted  through  the  nerve  and  through  the  dorsal  or  sensory 
root  to  the  cinerea  of  the  myelon.  Here  it  is  apparently  transformed  into  a  motor  im- 
pulse which  leaves  by  one  or  more  ventral  roots  and  causes  an  action  of  the  appropriate 
muscles  or  vessels  or  viscera.  This  kind  of  action,  which  may  be  very  complex,  is  called 
reflex,  and  the  cinerea  is  said  to  operate  as  a  center  for  the  reception  and  interpretation  of 
the  message  and  the  determination  of  the  response  to  be  made. 

§  1004.  Analogies  of  the  Nerwus  and  Vascular  Systems. — (A)  Somewhat  remotely^ 
the  twofold  division  of  the  former  into  the  sympathic  and  the  cerebrospinal  may  be  com- 
pared with  the  division  of  the  latter  into  the  lymph  and  the  blood  vascular  systems. 

(B)  Confining  the  comparison  to  the  better  known  and  more  extensive  divisions,  each 
])resents  a  central  and  a  peripheral  portion.  In  each  case  the  central  organs  are  relati'cely 
active  and  the  peripheral  passim. 

(C)  The  vefisels  carry  the  blood,  containing  the  elements  of  nourishment  and  the  pro- 
ducts of  waste,  together  with  heat.  The  nerves  transmit  impressions  and  impulses,  by 
means  of  which  the  different  organs  are  connected  and  made  capable  of  mutual  and  har- 
monious action.  Both  vessels  and  nerves  are  thus  channels  of  communication  ;  but  they 
differ  as  do  rivers,  canals,  roads  and  railways  from  the  telegraph  and  the  telephone.  The 
relations  established  are  of  commerce  on  the  one  hand  and  intelligence  on  the  other. 

(D)  Again,  as  the  vessels  are  of  two  kinds,  the  arteries  which  carry  blood  from  the 
heart  and  the  neins  which  return  it  thereto,  so  there  are  two  sets  of  nerves,  motor  and  sen- 
sory, which  transmit  impulses  in  one  direction  and  impressions  in  the  other.     The  direc- 


372  ANATOMICAL    TECHNOLOGY. 

tion  in  the  arteries  and  the  motor  nerves  is  centrifugal,  while  it  is  centripetal  in  the  sensory 
nerves  and  the  veins.  [For  this  reason,  upon  colored  diagrams,  it  is  at  least  convenient  to 
represent  the  motor  nerves  by  red,  the  color  of  most  arterial  blood,  and  the  sensory  nerves 
by  blue,  the  color  of  the  blood  in  most  of  the  veins]. 

(E)  Like  the  two  kinds  of  vessels,  the  motor  nerves  divide  and  subdivide  so  as  to  form 
smaller  and  smaller  branches,  while  the  sensory  nerves  unite  and  reunite  to  form  larger 
and  larger  trunks. 

§  1005-  Differences  between  the  Nervous  and  Vascular  ^sterns. — Here,  however,  the 
strict  analogy  ceases.  The  connection  of  the  two  sets  of  nerves  at  the  myelon  is  not  well 
understood,  but  it  is  certainly  less  simple  than  that  of  the  great  venous  and  arterial  trunks 
at  the  heart,  separated  as  they  are  only  by  the  lun^. 

Again,  while  the  capillaries  establish  a  complete  continuity  of  the  peripheral  ends  of 
the  arteries  and  veins,  no  such  constant  connection  has  been  shown  to  exist  between  the 
motor  and  sensory  nerves,  which  commonly  terminate  independently  either  in  muscle  or 
at  sensitive  surfaces  ;  but  see  Beale,  A,  240. 

The  subdivision  of  the  vessels  is  like  that  of  a  large  stream  into  several  smaller,  all 
being  part  of  one.  But  as  a  rule  the  nerve  fibers  maintain  their  independence  through- 
out their  course  from  the  myelon  to  the  termination,  and  the  larger  nerves  are  made  up 
by  the  association  of  many  fibers,  and  not  by  their  actual  union  into  one  larpre  fiber. 

Arteries  and  veins  differ  not  only  in  that  the  former  usually  contain  purer  blood  and  the 
latter  that  which  is  less  pure  (the  pulmonary  vessels  forming  exceptions  to  the  rale) ;  nor 
even  in  that  the  current  in  the  one  is  always  toward  the  heart  and  in  the  other  away 
from  it.  The  real  distinction  is  in  their  structure,  the  arteries  containing  more  elastic  and 
muscular  tissue,  by  virtue  of  which  they  are  more  perfectly  elastic  and  contractile  ;  their 
walls  also  are  relatively  thicker,  so  that  they  remain  open  when  empty  instead  of  collaps- 
ing like  the  veins.  But  no  such  distinctions  have  been  ascertained  between  the  motor  and 
sensory  nerves,  and  the  proof  that  a  sensory  nerve  may  transmit  an  impression  in  the 
direction  opposite  to  the  usual  one  goes  far  to  indicate  that  their  properties  as  well  as  their 
structure  are  identical,  and  that  the  difference  in  their  functions  depends  upon  the  connec- 
tions of  their  central  end  with  the  dorsal  and  ventral  regions  of  the  myelon  and  of  their 
l^eripheral  ends  with  muscles  or  with  sensitive  parts. 

THE    MYELENCEPHALIC    OR    CEREBRO-SPINAL 
NERVOUS   SYSTEM. 

§  1006.  The  Myelon. — This,  called  also  chorda  spinalis  or 
spinal  cord^  is  the  longer  and  more  slender  portion  of  the  mjelen- 
cephalon  or  central  part  of  the  cerebro-spinal  axis,  and  is  lodged 
within  the  canalis  neuralis  of  the  columna  vertebralis  (§  479). 

References  to  the  Myelon.— Q;y\a.m,  A,  I,  568,  and  II,  489  ;  Gray,  A,  602  ;  Hyrtl,  A,  463  ^ 
Gegenbaur  (Lankester),  A,  512  ;  Chauveau,  A,  709  ;  Chauveau  (Fleming),  A,  666  and  747  j| 
Gurit,  A,  715  ;  Owen,  A,  III,  73  ;  Milne -Edwards,  A,  XI,  257 ;  Lcyh,  A,  504. 

As  briefly  stated  in  §§  997,  998,  the  myelon  is  a  continuous  mass  of  alba  and  cinerea^ 
and  is  functionally  a  gigantic  motor  and  sensory  nerve,  an  elongated  ganglion  and  a  cen- 
ter of  reflex  actions.     It  may  be  conveniently  divided  into  regions  corresponding  witlij 
those  of  the  vertebral  column,  cervical,  thoracic,  lumbar,  sacral  and  caudal ;  but  the  ana- 
tomical distinctions  between  them  consist  chiefly  in  the  increase  or  decrease  of  the  cinerea 


THE    MYELONAL    NERVES.  373 

or  of  tlie  alba.  Corresponding  with  the  origins  of  the  large  nerves  forming  the  brachial 
and  sacral  plexuses,  and  supplying  respectively  the  arms  and  the  legs,  the  myelon  presents 
enlargements  which,  from  their  location,  are  known  as  the  cermcal  and  lurribar  enlarge- 
ments. The  cephalic  end  diiaers  from  the  rest  in  several  respects,  which  will  he  indicated  in 
Chap.  X ;  it  is  commonly  regarded  as  a  division  of  the  brain  under  the  name  of  medulla 
or  meteiuephalon. 

The  dorsal  aspect  of  the  cervical  and  of  part  of  the  thoracic  myelon  is  represented  in 
Fig.  104  ;  transections  of  it  are  given  in  Fig.  99,  100,  109  and  112. 

^  1007.  The  Myelonal  or  tvpiiial  Nerces. — These  arise  from  the  myelon  or  spinal  cord 
(Fig.  104)  and,  except  in  the  lumbar  region,  pass  almost  directly  laterad  through  the  inter- 
vertebral foramina,  and  are  distributed  to  the  tissues.  If  a  section  of  the  body  be  made  at 
the  proper  level,  as  in  Fig.  109,  it  will  be  seen  that  the  nerves  are  in  pairs,  and  that  each 
nerve  trunk  arises  by  two  roots— i\\e  dorsal  (posterior)  root  arising  from  the  dorso-lateral 
aspect  of  the  myelon,  and  the  ventral  (anterior)  root  from  the  veutro-lateral  aspect.  These 
extend  toward  the  intervertebral  foramen,  piercing  the  dura  on  their  way.  In  the  foramen 
they  unite  to  form  the  nerve  trunk,  but  just  as  they  unite  there  appears  on  the  dorsal  (pos- 
terior) root  a  swelling — the  ganglion  of  the  dorsal  root  (§  999), 

The  nerve  trunk  soon  divides  into  two  primary  divisions — the  dorsal  or  posterior  pri- 
mary and  the  ventral  or  anterior  primary  division  (Fig.  109),  The  dorsal  primary  division 
supplies  the  parts  dorsad  of  the  spinal  column,  while  the  ventral  supplies  the  parts  ven- 
trad  of  the  spinal  column,  including  the  limbs.  For  the  most  part,  the  ventral  are  much 
larger  than  the  corresponding  dorsal  divisions ;  the  suhocclpital  and  the  great  occipital 
nerves  are,  however,  exceptions  (see  exijlanation  of  Fig.  104).  The  myelonal  nerves  are 
sometimes  designated  by  the  names  of  the  groups  of  vertebrae  through  whose  intervertebral 
foramina  they  emerge — cervical,  thoracic,  lumbar,  sacral  and  coccygeal  or  caudal  (§  463). 

Preparation — Fig.  104. — The  muscles  covering  the  spinal  column  were  first  carefully 
removed  on  the  left  to  the  level  of  the  vertebral  laminae.  The  neural  arch  was  removed 
with  nippers,  entirely  on  the  left,  partly  on  the  right.  This  exposed  the  myelon,  the  nerves, 
and — on  the  left— the  vertebrarterial  canal  with  its  contained  vertebral  artery.  The  left 
nerves  were  then  isolated  by  commencing  at  their  origin  and  tracing  the  ventral  primary 
division  peripherad,  removing  the  muscles  and  connective  tissue  with  the  tracer,  forceps 
and  scissors.  The  MM.  rhoinboideus  and  serratus  {magnus)  were  cut  and  the  scapula 
strongly  lateriducted,  to  expose  the  brachial  plexus.  The  parts  of  this  plexus  were  then 
carefully  isolated ;  (compare  with  the  ventral  view.  Fig.  106).  On  the  right,  the  dorsal 
primary  divisions  of  the  nerve  trunks  were  isolated  as  described  for  the  left  (see  also 
§  1008).  They  are  as  a  rule  smaller  than  the  ventral,  and  hence  require  more  care  for 
tlieir  isolation.  The  myelonal  dura  was  entirely  removed  from  the  left  side  with  the  fine 
forceps  and  scissors,  but  only  to  the  level  of  emergence  of  the  nerves  on  the  right. 
Finally,  the  skull  was  nipped  away  from  the  dorsal  and  lateral  aspects  of  the  brain,  com- 
mencing at  the  foramen  magnum  (Fig.  55) ;  see  Chap.  X. 

In  preserving  this  specimen,  the  rectum  was  cleared  and  the  abdomen  and  thorax  filled 
with  95  per  cent,  alcohol  (§  282) ;  then  it  was  suspended  in  a  jar  of  alcohol  (§  286)  by  a 
cord  tied  to  the  tail  and  legs.  Cotton  was  placed  in  the  metacoelia  or  4th  ventricle,  to 
raise  the  cerebellum,  and  between  the  hemispheres,  to  divaricate  them  sufficiently  to 
show  the  callosum. 

Explanation  of  Fig.  104.— Cerebellum,  az. — Epencephalon  ;  Chapter  X.  Costse  (7) 
— The  first  seven  ribs.  Dura — Dura  mater  of  the  myelon.  Fm.  alt.,  Foramen  atlantale 
The  atlantal  foramen  in  the  cephalo-dorsal  margin  of  the  atlas  ;  through  it  pass  the  A. 
vertebralis  and  the  i\r,  suboccipitalis  or  1st  cervical  nerve.     Ganglion — Ganglion  on  the 


sn 


ANATOMICAL    TECHNOLOGY. 


Fig.  104.— Doksai^  Aspect  op  the  Braix  and  of  part  of  the  Myelon  with  its 

NEiiVES ;  X  .75. 


DISSECTION    OF    THE    NERVOUS    SYSTEM,  375 

dorsal  (posterior)  root  of  the  6th  left  cervical  nerve  ;  ganglia  are  present  on  all  as  shown  in 
this  figure ;  see  also  Fig.  109.  Hemisphaerae — Cerebral  hemispheres,  prosencephalon  ; 
see  Chap.  X.  MM.  (Iv.  scp.)  levator  anguli  scapulae  et  serratus  (magnus)(§  664).  M. 
sbscp.,  M.  subscapularis— The  light  streak  between  this  and  the  preceding  muscle  is 
the  glenoid  border  of  the  scapula  (Fig.  44).  M.  supraspinatus— See  §  673.  MM.  tra- 
pezii — Trapezius  muscles  ;  see  Fig.  66.  N.  accessorius — The  spinal  accessory  nerves  (xi) ; 
this  nerve  passes  along  the  ental  surface  of  the  trapezius  muscle  ;  see  also  Chap.  X.  N. 
crcm.,  N.  circumflexus  (§  1024).  N.  ctn.  int.,  N.  cutaneus  internus  (§  1021).  N. 
hpgls.,  N.  hypoglossus — The  12th  pair  of  cranial  nervej  ;  Chap.  X.  N.  latis.,  N.  latis- 
simus — Nerve  of  the  M.  latisaimus  dorsi  (§  1023).  N.  medius  s.  medianus  (§  1025).  N. 
m.  spiralis,  N.  musculo-spiralis  (§  1026).  N.  m.  ctn.,  N.  musculo-cutaneus  (§  1022). 
NN.myen.,  dv.  dsl.,  NN.  myelencephalici,  divisio  dorsalis  (15) — Dorsal  (posterior) 
primary  division  of  the  first  15  myolencephalic  or  cerebrospinal  nerves.  NN.  myen.,  dv. 
vnt.  (15),  NN.  myelencephalici,  divisio  ventralis — The  ventral  (anterior)  primary  divi- 
sion of  the  first  15  my  el  encephalic  or  cerebro-spinal  nerves.  N.  oc.  (occipitalis)  major — 
This  forms  the  dorsal  part  of  the  2d  cervical  nerve  ;  it  receives  a  large  anastomotic  branch 
from  the  3d  cervical  nerve  ;  this  nerve  is  distributed  to  the  dorsal  and  caudal  regions  of 
the  head ;  in  the  1st  and  2d  cervical  nerves  the  dorsal  primary  divisions  are  as  large  or 
larger  than  the  ventral  (§  10U7).  N.  rhmb.,  N.  m.  rhomboidei— Nerves  of  the  romboideus 
muscle.  N.  sbscp.,  N.  subscapularis  (^§  042  and  1023).  N.  spscp.,  N.  suprascapu- 
laris — A  large  nerve  from  the  brachial  plexus  ;  it  sends  a  branch  to  the  clavicular  end  of 
the  clavo-trapezius,  but  is  mainly  distributed  to  the  scapular  muscles ;  it  is  in  company 
with  the  suprascapular  artery;  see  §§937,  1020,  and  Fig.  105.  N.  suboccipitalis— The 
1st  myelonal  nerve  ;  its  name  is  not  written,  but  it  traverses  the  Fm.  atl.  with  the  A.  ver- 
tehralis.  N.  thr.  post.,  N.  thoracicus  posterior — The  external  respiratory  of  Bell  (§  1029); 
see  §  1019  for  the  internal  respiratory  or  phrenicus.    N.  ulnaris  (§  1028). 

§  1008.  General  Directions  for  Dissecting  the  Nervous  Sys- 
tem.— The  precautions  mentioned  in  §  596  (10)  should  be  carefully 
observed,  and  especial  care  taken  that  the  part  under  examination 
should  be  in  a  good  light.  Employ  a  tripod  magnifier  (Fig.  36) 
whenever  necessary  to  determine  the  course  or  relations  of  small 
branches.  Change  the  position  of  the  cat  as  often  as  is  necessary 
to  get  the  given  part  in  the  best  light  or  to  make  it  more  accessible. 

Whenever  a  part  is  dissected,  it  should  be  kept  moist  by  recov- 
ering it  with  skin  or  sheet  rubber,  or  by  placing  upon  it  a  tuft  of 
cotton  wet  with  15  per  cent,  glycerin  (§  170). 

In  fresh  animals,  nerves  may  be  distinguished  from  connective 
tissue  or  empty  vessels  by  their  glistening  and  wavy  or  crimped 
appearance  when  looked  at  closely.  An  uninjected  vessel  may 
always  be  distinguished  by  cutting  a  slit  in  it  and  demonstrating 
its  tubular  character  with  the  tracer. 

§  1009.  Instruments  and  Material. — Fifteen,  per  cent,  glycerin  ;  cotton  ;  towels  or 
cloths;  pins;  tracer;  jfine,  coarse  and  bone  scissors;  nippers;  scalpels;  arthrotome  ; 
injecting  apparatus  and  material  (Chapter  IV) ;  skeleton,  and  a  natural  skeleton  of  the 

arm  (§  252). 


376  ANATOMICAL    TECHNOLOGY. 

Choic3  of  Specimen. — A  lean  cat  with  milk  teeth  is  preferable  ;  young,  because  the 
bones  are  softer  and  more  easily  cut ;  lean,  because  the  tracing  of  nerves  is  diflBcult  even 
when  unobscured  by  fat.  The  usual  precautions  for  cleanliness  should  be  observed  (§  199), 
and  if  it  be  desired  to  demonstrate  the  vertebral  artery  as  in  Fig.  104,  the  arteries  should 
be  injected  from  the  abdominal  aorta  or  the  femoral  artery  (§§  845,  363).  The  cat  should 
bs  deprived  of  blood  by  opening  the  V.femoralis  near  Poupart's  ligament,  centrad  of  the 
last  pair  of  valves  (§  362),  or  the  postcava  may  be  opened. 

Posture. — Place  the  cat  ventricumbent  with  a  block  between  tlie 
arms  and  under  the  neck,  so  that  the  structures  on  the  dorsal  part 
of  the  body  may  be  somewhat  tense.  The  legs  should  be  tied  to 
the  tray,  so  that  the  subject  will  not  move  too  much. 

§  1010.  Exposure  and  Dissection.— Vart  the  hair  (§  354)  along 
a  line  1  cm.  sinistrad  of  the  dorsimeson,  commencing  at  the  base  of 
the  skull  and  ending  opposite  the  glen o- vertebral  angle  of  the  scap- 
ula. Cut  the  skin  along  this  line  and  reflect  it  for  2-3  cm.  on  the 
left  and  just  beyond  the  dorsimeson  on  the  right.  In  reflecting  the 
skin  on  the  right,  it  should  be  to7'n  from  the  body  rather  than  cut, 
so  that  the  nerves  passing  into  the  skin  may  be  more  easily  de- 
tected. During  the  dissection  the  parts  should  be  kept  covered 
with  skin  as  much  as  possible  and  moistened  occasionally  with  15  per 
cent,  glycerin.  In  case  it  takes  more  than  one  day  to  complete  the 
study,  the  preparation  should  be  moistened  with  15  per  cent,  gly- 
cerin, covered  with  skin  and  then  with  a  damp  towel,  and  kept  in  a 
cool  place.  As  the  dissection  of  a  given  part  is  completed,  there 
should  be  laid  upon  it  a  tuft  of  cotton  moistened  with  15  per  cent, 
glycerin. 

§  1011.  Demonstration  of  the  Ventral  Primary  Division  of 
Nerves  of  the  Left  Side  (Fig.  104). — After  the  skin  is  reflected  on 
the  left  side,  commence  in  the  7th  intervertebral  space  and  cut  the 
muscles  from  the  left  half  of  the  neural  arch  (g  478),  and  with  the 
tracer  carefully  isolate  the  nerve  as  it  emerges  through  the  interver- 
tebral foramen  (§  484).  Then  with  the  nippers  remove  the  left  half 
of  the  neural  arch,  and  the  origin  of  the  nerve  from  the  myelon  will 
be  seen.  Continue  to  expose  the  nerves  in  this  way  until  the  2d 
cervical  or  great  occipital  nerve  is  reached.  This  does  not  emerge 
through  a  special  intervertebral  foramen,  but  between  the  arches  of 
the  atlas  and  axis  ;  hence  the  ganglion  is  imbedded  in  the  muscles. 
It  is  most  safely  isolated  by  tracing  it  from  the  surface  toward  its 
origin.  This  nerve  is  easily  seen  on  the  caudal  part  of  the  head  and 
through  the  clavo-trapezius  muscle  if  the  cat  is  lean.  One  might 
also  begin  with  the  N.  auricularis  magnus  (Fig.  87)  the  ventral 


I 


DORSAL    DIVISION    OF   SPINAL    NERVES,  377 


primary  division  of  the  2d  cervical.  Use  the  scalpel  and  tracer  to 
remove  the  muscles.  After  the  ganglion  is  exposed,  the  neural 
arch  may  be  removed  as  usual  with  nippers. 

The  removal  of  the  1st  or  suboccipital  also  requires  care,  as  it 
traverses  the  atlantal  foramen.  The  muscles  must  be  carefully 
removed  from  the  dorsal  side  of  the  atlas,  commenciixg  caudad. 
The  ganglion  of  this  nerve  is  either  in  the  muscles  immediately  cov- 
ering the  Frrt.  atlantale  (§  474)  or  just  within  the  mouth  of  the  fora- 
men ;  hence  the  muscles  must  be  very  carefully  removed  until  the 
nerve  is  uncovered.  It  may  then  be  traced  peripherad  as  far  as 
desired,  and  the  dorsal  part  of  the  atlas  removed  wdth  nippers. 

If  it  be  desired  to  follow  the  brachial  plexus  as  shown  in  Fig. 
104,  the  rJioTnboideus  and  trapezius  muscles  must  be  removed  (Fig. 
QQ^  67),  and  also  part  of  the  serratus  magnus  (Fig.  73).  Then  the 
scapula  shoukl  be  strongly  lateri ducted.  This  will  expose  the 
hracJiial  plexus  and  its  anastomoses,  and  the  final  trunks  may  be 
made  out  by  carefully  dissecting  with  the  tracer,  tine  forceps  and 
line  scissors.  The  1st  thoracic  will  be  seen  to  pass  entad  of  the  1st 
rib  on  its  way  to  join  the  brachial  plexus. 

The  distribution  of  the  N.  accessorius  (xi)  may  be  easily  found, 
as  it  extends  along  the  ental  surface  of  the  M.  trapezius,  reaching 
this  point  soon  after  its  emergence  from  the  Fm.  jugular e  in  com- 
pany with  the  NW.  vagus  et  glossopJiaryngeus ;  see  §  562. 

§  1012.  Demonstration  of  the  Dorsal  {Posterior)  Primary  Division  of  the  Nerves  on  the 
Right  Side  (Fig,  104). — In  removing  the  skin  from  the  right  side,  it  should  be  torn  rather 
than  cut  :  then  the  branches  of  the  dorsal  primary  division  going  to  the  skin  will  be  seen 
as  white  cords  which  penetrate  the  muscles  in  the  dorsal  region  and  pass  to  the  skin. 
These  branches  should  be  followed  through  the  muscles,  using  tracer,  scissors,  scalpel 
and  forceps  as  is  necessary.  Trace  the  dorsal  division  until  it  joins  the  ventral  division 
(Fig.  109).  After  the  nerves  are  isolated,  the  right  side  of  the  neural  arch  should  be 
removed  to  the  level  of  the  intervertebral  foramina.  After  the  myelonal  nerves  are  iso- 
lated and  the  myelon  uncovered,  some  cotton  wet  with  15  per  cent,  glycerin  should  be 
placed  upon  the  myelon  and  damp  towels  over  the  whole  dorsal  region,  to  protect  the 
parts  from  injury  or  drying, 

§  1013.  Exposure  of  the  Brain.— The  12th,  11th,  10th,  9th  and 
7th  cranial  nerves  (PI.  I,  II),  on  the  left  side  should  be  isolated.  In 
doing  this,  have  at  hand  a  skull  and  Fig.  5Q,  57,  59  and  107,  also  the 
Table  in  §  562.  If  the  structures  are  carefully  removed  opposite  the 
points  of  exit  of  the  various  nerves,  they  may  be  easily  found  and 
traced  as  far  peripherad  as  desired.  After  the  nerves  are  isolated, 
the  roof  of  the  skull  should  be  removed  with  nippers.    In  doing 


.378 


ANA  TOMICAL     TECHNOL  0  G  Y, 


Fig.  105.— Ventral  Aspect  of  the  Right  Brachial  Plexus  and  its  Nerves  ;   x  .9 


THE    BE  ACUTA  L    PLEXUS.  379 

this,  ventriduct  the  head  and  insert  one  blade  of  the  nippers  into 
the  foramen  magnum  (Fig.  56,  57,  59),  and  remove  the  0.  supraoc- 
cipitale  piecemeal.  Remove  also  the  parietal  and  frontal  bones  in 
the  same  way  until  the  dorsal  aspect  of  the  brain  is  entirely  uncov- 
ered. The  bony  tentorium  (Fig.  59,  88)  will  remain,  but  its  dorsal 
border  will  be  free.  To  remove  it,  separate  slightly  the  hemispheres 
and  cerebellum,  insert  the  nippers  and  break  the  tentorium  on  both 
sides.    It  may  then  be  removed  with  the  coarse  forceps. 

§  1014.  Removal  of  the  Dura. — After  the  hard  parts  are  re- 
moved from  the  central  nervous  system,  the  dura,  a  tough  membra- 
nous sac  enclosing  it,  should  be  partly  removed  by  grasping  the 
membrane  at  some  point  where  it  is  relaxed  and  cutting  away  a 
piece  at  a  time.  Grasp  the  cut  edge  of  the  dura  with  the  forceps 
and  lift  it  away  from  the  underlying  nervous  matter  so  that  the 
scissors  may  be  inserted.  Remove  the  dura,  proceeding  with  ex- 
treme caution,  especially  around  the  nerve  roots.  Sometimes  it 
will  be  necessary  to  employ  fine  scissors  and  fine  forceps  and  the 
tripod  magnifier,  especially  in  cutting  the  dura  from  the  roots  of 
the  cranial  nerves.  The  fan-like  appearance  of  some  of  the  nerve 
roots  on  their  emergence  may  be  well  seen  with  the  magnifier. 


THE  BRACHIAL   PLEXUS   AND  THE  PRINCIPAL  NERVES  OF   THE  RIGHT 
ARM   AND   SCAPULAR  REGION. 

References.— Quain,  A,  I,  582  ;  Gray,  A,  671  ;  Hyrtl,  A,  543  ;  Gegenbaur  (Lankester), 
A,  514;  Chaiiveau,  A,  800  ;  Chauveau  (Fleming),  A,  754;  Gurlt,  A,  749;  Owen,  A,  III, 
170,  176  ;  Milne-Edwards,  A,  XI,  239  ;  Leyli,  A,  537. 

Instruments  and  material,  see  ^  1009. 

§  1015.  The  Brachial  Plexus  is  the  network  of  nerves  from  which  the  scapular 
region  and  the  arm  are  supplied.  It  is  formed  by  the  intimate  connection  of  the  ventral 
(anterior)  primary  divisions  (§  1007)  of  the  6th,  7th  and  8th  cervical  and  the  1st  tho- 
racic nerves. 

Fig.  105  and  the  description  are  given  to  illustrate  the  relations  and  distribution  of 
spinal  or  myelonal  nerves  in  a  well  defined  region. 

For  the  study  of  this  subject,  the  student  should  have  before  him  a  natural  skeleton  of 
the  arm,  including  the  scapula  (§  252). 

§  1016.  Specimen,  Posture  and  Preparation. — The  same  specimen  may  be  employed 
as  for  Fig.  104,  but  it  is  better  to  use  a  different  one.  It  should,  however,  be  of  the  same 
character,  mz.,  young  and  lean. 

Preparation  of  Fig.  105. — The  cat  was  injected  from  the  abdominal  aorta  with  thin 
plaster  (g§  345,  363).  Then  the  skin  was  removed  from  the  axillary  and  pectoral  regions, 
and  from  the  caudal  aspect  of  the  arm  to  the  wrist.  The  pectoral,  claw-ma stoid,  clavo- 
trapczias,  epitrochlearis  and  pronator  teres  muscles  (§§  680,  681)  were  then  cut  and  turned 


380  ANATOMICAL    TECHNOLOGY. 

aside.  The  veins  of  the  arm  were  wholly  removed,  the  arteries  and  nerves  carefully 
traced  with  fine  scissors,  forceps  and  tracer.  The  animal  was  transected  (§  234)  and  the 
cephalic  half  preserved  in  alcohol  (§  286). 

Explanation  of  Fig.  105. — A.  carotidea — The  right  carotid  artery  (§927).  A.  spscp., 
A.  suprascapularis — The  suprascapular  artery  ;  the  main  branch  of  this  artery  accompa- 
nies the  N.  suprascapularis,  but  in  this  figure  only  the  smaller  branch  of  the  artery  to  the 
trapezius  muscle  is  shown  ;  see  §  937.  A.  crcm.,  A.  circumflexa — The  circumflex  artery 
(§  941).  A.  sbsc,  A.  subscapularis— The  subscapular  artery  (§  942).  A.  axl.,  A.  axil- 
laris— The  axillary  artery  (§  938).  A.  thor.  (thoracica)  longa — The  long  thoracic  artery 
(§  940).  A.  thor.  ant.,  A.  thoracica  anterior  (§  939).  A.  br.,  A.  brachialis— The  bra- 
chial artery  (§  943).  A.  ulnaris — The  ulnar  artery  (§  945).  A.  interosseus — The  inter- 
osseous artery  (§  944,  D).  A.  radialis— The  radial  artery  (§  946).  Eminentia  hypothenaris 
— The  hypothenar  eminence.  Fm.  eptrch.,  Foramen  epitrochleare  ;  see  Fig.  46. 
MM.  pectorales — The  cut  end  of  the  pectoral  muscles  (§  640).  M.  crcd,  M.  coracoideus 
(§  668).  M.  biceps  (§  691).  M.  entrc,  dv.  cd.,  M.  entotriceps,  divisio  caudalis  (§  685). 
M.  medtrc,  M.  meditriceps  (§  683).  M.  eptrch.,  M.  epitrochlearis  (§  681).  M.  serra- 
tus  (magnus),  (§  664).  M.  scalenus.  M.  rectus  thor.  (thoracicus).  N.  vagus  et  sym. 
(sympathicus),  (Fig.  107).  N.  crv.  (4),  N.  cervicalis  (4).  N.  crv.  (5),  N.  cervicalis 
(5).  N.  crv.  (6),  N.  cervicalis  (6).  N.  spscp.,  N.  suprascapularis — The  suprascapular 
nerve  (§  1020).  N.  phrn.,  N.  phrenicus — The  phrenic,  diaphragmatic  or  internal  respira- 
tory nerve  (§  1019) ;  see  §  1029  for  the  external  respiratory.  N.  thr.  ant.  (ectal  s.  cph.), 
N.  thoracicus  anterior  (ectalis  s.  cephalicus) — The  anterior  (ectal  or  cephalic)  division 
of  the  thoracic  nerve  (§  1018).  N.  m.  ctn.,  N,  musculo-cutaneus— The  musculo-cutane- 
ous  or  the  external  cutaneous  nerve  (§  1022)..  N.  sbscp.,  N.  subscapularis — The  sub- 
scapular nerve  (§  1023).  N.  crcm.,  N.  circumflexus— The  circumflex  nerve  (§  1024).  N. 
m.  spiralis,  N.  musculo-spiralis — The  musculo-spiral  nerve  (§  1026).  N.  medius  s.  me- 
dianus — The  median  nerve  (§  1025).  N.  int.  ctn.,  N.  cutaneus  internus — The  internal 
cutaneous  nerve  (§  1021).  N.  latis.,  N.  m.  latissimi — Nerve  of  the  latissimus  or  the 
long  subscapular  nerve  (§  1023).  N.  thr.  ant.  (ental.  s.  cd.),  N.  thoracicus  anterior  (en- 
tails s.  caudalis). — The  anterior  (ental  or  caudal)  thoracic  nerve  (§  1018).  N.  thr.  post., 
N.  thoracicus  posterior — The  posterior  thoracic  or  the  external  respiratory  of  Bell 
(§§  1018, 1029).  N.  radialis — The  radial  nerve,  a  branch  of  the  musculo-spiral  (^  1026). 
N.  interos.  ant.,  N.  interosseus  anterior — The  anterior  interosseous  nerve  ;  the  pos- 
terior interosseus  is  a  branch  of  the  musculo-spiral  (§§  1025,  1026).  Pili  tactiles— Tactile 
hairs  ;  to  these  extend  a  branch  of  the  N.  ulnaris  (§  1028).  Ramus  dorsalis — The  dorsal 
branch  of  the  ulnar  nerve  (§  1029).     Trachea — The  windpipe  (§  799). 

Preparation  of  Fig.  106. — This  is  the  same  as  for  Fig.  105,  except  that  all  of  the  soft 
parts  were  removed  so  as  to  show  the  exit  of  the  nerves  from  the  intervertebral  foramina. 

Explanation  of  Fig.  106.— A.  brachialis— The  brachial  artery.  N.  suprascapularis 
—The  suprascapular  nerve.  N.  crv.  (6),  N.  cervicalis — The  6th  cervical  nerve.  N.  sub- 
scapularis— The  subscapular  nerve.  N.  crv.  (7),  N.  cervicalis— The  7th  cervical  nerve. 
N.  musculo-cutaneus— The  musculo  cutaneous  or  external  cutaneous  nerve.  N.  crcm., 
N.  circumflexus— The  circumflex  nerve.  N.  thr.  ant.  (ectal.  s.  cph.),  N.  thoracicus 
anterior  (ectalis  s.  cephalicus) — The  anterior  (ectal  or  cephalic)  division  of  the  thoracic 
nerve.  N.  medius  s.  medianus — The  median  nerve.  N.  musculo-spiralis — The  name 
is  not  written,  but  it  is  the  large  blank  one  arising  from  the  8th  cervical  ;  see  Fig.  104  and 
105,  §  1026.  N.  crv.  (8),  N.  cervicalis— The  8th  cervical  nerve.  N.  ulnaris— The  ulnar 
nerve.  N.  thr.  (1),  N.  thoracicus  s.  dorsalis— The  1st  thoracic  or  dorsal  nerve.  N. 
cutaneus  internus — The  internal  cutaneous  nerve.      N.   latis.,   N.  m.   latissimi — The 


THE    BRACHIAL    PLEXUS. 


381 


yn.Tn.  l^y cdor  am*  scp 
and    rh.omlreideJjs 


Fig.  106. — Diagram  of  the  Right  Brachial  Plexus,  Ventral  View  ;  x  about  3. 

lerve  of  tlie  M.  latissimus  dorsi  or  the  long  subscapular  nerve  (§  1023).  N.  thr.  ant, 
ental.  cd.),  N.  thoracicus  anterior  (entalis  s.  caudalis) — The  anterior  thoracic  nerve, 
ntal  or  caudal  division.  N.  thr.  post.,  N.  thoracicus  posterior — The  posterior  thoracic 
\orve  or  the  external  respiratory  of  Bell.  To  M.  levator  ang.  scp.  and  rhomboideus — 
The  nerve  to  the  levator  angull  scapuloe  and  rhomboideus  mvscles.  To  M.  clavo-deltoi- 
leus — The  nerve  to  the  clavo-deltoideus  muscle. 

Dissection  of  the  Brachial  Plexus. — The  cat  should  be  dorsi- 
umlbent  and  the  arms  secured  laterad  with  cords  as  in  Fig.  76. 
A  block  should  be  placed  flatwise  under  the  shoulders,  so  that  the 
head  may  be  slightly  dorsiducted  ;  later  in  the  dissection,  the  arm 
may  be  supported  by  a  block.  The  arteries  should  be  injected 
with  thin  plaster  (§§  345,  352,  363),  from  either  the  abdominal  aorta 
or  the  femoral  artery.  If  the  cat  is  to  be  used  only  for  this  prepa- 
ration, it  should  be  transected  (§  234). 

§  1017.  Exposure. — Make  a  longitudinal  incision  through  the 
skin  2  cm.  dextrad  of  the  ventrimeson,  commencing  at  about  the 
middle  of  the  neck  and  ending  opposite  the  base  of  the  xiphisternum. 


3  82  ANA  TOMICAL     TECHNOL  OGY. 

Then  make  a  transverse  incision  2-3  cm.  long,  from  the  beginning 
of  the  longitudinal  incision,  dextrad.  Then,  commencing  at  a  point 
opposite  the  1st  rib,  cut  through  the  skin  along  the  caudal  {upper 
in  present  posture)  side  of  the  arm  to  the  elbow.  After  the  nerves  are 
studied  in  the  brachium,  the  longitudinal  incision  on  the  caudal 
side  of  the  arm  will  be  continued  to  the  pad  in  the  palm  of  the  hand. 

Reflect  the  skin  just  across  the  ventrimeson  by  grasping  the  cut 
edge  and  tearing  it  from  the  structures  which  it  covers.  Grasp  the 
corner  of  the  cephalic  flap  and  tear  the  skin  from  the  arm  and 
shoulder,  exposing  as  much  as  is  shown  in  Fig.  105.  Reflect  the 
skin  from  the  dorsal  side  of  the  arm  in  the  same  way,  because,  if 
done  in  this  manner,  any  nerves  entering  it  can  be  readily  seen, 
whereas  if  the  scalpel  is  used  freely,  they  will  be  cut  with  the  con- 
nective tissue. 

After  the  skin  is  reflected,  make  an  incision  through  the  muscles 
2  cm.  from  the  ventrimeson,  commencing  and  ending  as  for  the  skin. 
It  is  necessary  to  proceed  with  extreme  caution,  to  avoid  cutting  the 
vessels  and  nerves  entad  of  the  muscles.  In  the  neck  the  cut  should 
divide  only  the  muscles  covering  the  carotid  artery,  the  xagus 
and  sympathic  nernes  (Fig.  101).  It  is  best  to  uncover  these  struc- 
tures at  the  beginning  of  the  incision  and  keep  them  in  view.  In 
cutting  the  pectoral  muscles,  one  should  proceed  in  the  same  man- 
ner. When  the  muscles  are  divided,  the  mesal  edge  should  be 
grasped  by  the  hand  and  turned  mesad,  taking  care  not  to  break 
any  of  the  nerves  entering  them.  The  lateral  ends  of  the  muscles 
should  likewise  be  turned  laterad  with  the  same  caution.  Finally, 
separate  carefully  the  MM.  epitrocJilearis  and  biceps  to  the  elbow, 
cutting,  however,  just  deep  enough  to  expose  the  internal  cutaneous 
and  median  nerves  (Fig.  105).  The  above  incisions  will  expose  the 
brachial  plexus  and  the  principal  branches  arising  therefrom. 

Commencing  as  near  the  meson  as  possible,  with  tracer,  fine  for- 
ceps and  1\ne.  scissors,  remove  fat  and  connective  tissue  from  the 
vessels  and  nerves.  Fat  is  moderately  tender,  and  both  it  and  con- 
nective tissue  are  more  easily  torn  than  either  blood  vessels  or 
nerves  ;  the  nerves  too  may  be  recognized  as  directed  above  (§  1008) ; 
the  arteries,  being  filled,  will  serve  as  landmarks.  The  axillary 
vein  should  be  removed,  great  care  being  used  so  that  no  nerves 
are  cut  in  the  operation. 

§  1018.  N.  thoracicus  anterior  (Fig.  105,  106 ;  Quain,  A,  I,  584  ; 
Gray,  A,  672). — The  anterior  thoracic  nerve  passes  ventrad  from  the 


N.    PHRENICUS.  383 

brachial  plexus  to  the  pectoral  region.  It  is  divided  into  two  parts, 
or  rather  there  are  two  nerves — an  ectal  or  cephalic  division,  accom- 
panying the  anterior  thoracic  artery  between  the  muscles  (§  939), 
and  an  ental  or  caudal  division,  accompanying  the  long  thoracic 
artery  (§  940),  and  distributed  to  the  pectoral  and  also  somewhat 
to  the  latlssimus  muscle.  The  two  are  connected  near  their  origin 
by  an  anastomosing  branch,  as  shpwn  in  Fig.  105  and  106. 

Dissection. — If  the  section  was  properly  made  through  the  pec- 
toral muscles,  the  ectal  or  cephalic  division  will  be  turned  mesad  and 
the  ental  division  laterad.  Both  are  easily  found,  and  their  relations 
and  distribution  can  be  determined  by  using  the  tracer  and  fine 
forceps. 

§  1019.   N.  phrenicus  s.  diaphragmaticus  (Fig.  103,  105, 107  ; 

Quain,  A,  I,  578 ;  Gray,  A,   669). — This  nerve  is  formed  by  two 

branches^  one  from  the  5th  and  one  from  the  6th  cervical  nerve.    It 

1  also  occasionally  receives  a  branch  from  the  4th  cervical,  as  in  man. 

The  latter  condition  is  shown  in  Fig.  105,  while  the  more  frequent  one 

i  is  shown  in  Fig.  107.     These  branches  unite  near  the  1st  rib,  and  the 

I  phrenic  then  passes  into  the  thorax  on  the  mesal  side  of  the  A.  ster- 

nalis  (Fig.  107,  109).     The  right  nerve  rests  on  the  lateral  aspect  of 

the  prse-  and  postcavse  on  its  way  to  the  diaphragm,  to  which  it  is 

distributed.     The  course  of  the  left  is  well  shown  in  Fig.  103  and 

I  107,  N.phrn, 

Dissection. — The  branches  forming  the  phrenic  nerve  are  quite 
small,  hence  it  is  best  to  trace  the  nerve  centrad  from  the  point 
where  it  enters  the  thorax  ;  the  branches  may  then  be  isolated  one 
i  by  one.  AVhen  this  is  done,  the  costicartilages  and  the  thoracic 
■  walls  may  be  cut  and  the  two  edges  divaricated.  The  nerve  will 
appear  very  clearly  as  a  white  cord  passing  along  the  lateral  aspect 
of  the  prse-  and  postcavse  to  the  diaphragm. 

§  1020.  N.  suprascapularis  (Fig.  104, 105, 106 ;  Quain,  A,  I,  583  ; 
Gray,  A,  672). — The  suprascapular  nerve  arises  from  the  6th  cervi- 
cal. It  passes  directly  laterad  for  a  short  distance  and  then  divides 
into  two  branches,  one  going  to  the  ental  surface  of  the  M.  clavo- 
deltoideus^  the  other  to  the  ectal  surface  of  the  scapula.  These  two 
branches  accompany  the  branches  of  the  suprascapular  artery 
(I  937). 

I  Dissection. — This  nerve  is  easily  traced.     It  follows  closely  the 
'responding  branches  of  the  suprascapular  artery,  and  may  be 
ced  as  directed  for  that  vessel  (§  937). 
i 


384  ANATOMICAL     TECHNOLOGY. 

%  1021.  N.  cutaneus  internus  (Fig.  104,  105,  106  ;  Quain,  A,  I, 
585 ;  Gray,  A,  675). — The  internal  cutaneous  nerve  arises  wholly 
from  the  1st  thoracic.  It  becomes  subcutaneous  at  about  the  distal 
third  of  the  brachium,  emerging  from  between  the  epitrochlearis 
and  biceps  muscles  about  opposite  the  point  where  the  iV.  radialis 
emerges  from  between  the  biceps,  clavo-deltoideus  and  ectotriceps 
(Fig.  74) ;  hence  it  is  liable  to  be  destroyed  in  removing  the  skin  or 
in  the  exposure  (§  1017)  unless  care  is  taken.  It  gradually  curves 
from  the  dorso-caudal  to  the  ventral  aspect  of  the  arm,  and  is  dis- 
tributed mostly  to  the  skin  of  the  brachium  and  antebrachium  on 
the  caudal  and  ventral  aspects. 

Dissection. — It  is  best  to  isolate  the  1st  thoracic  near  its  origin 
to  find  the  origin  of  the  internal  cutaneous  nerve ;  it  may  then  be 
traced  periplierad,  or  it  may  be  found  on  the  ventral  side  of  the 
arm,  where  it  becomes  subcutaneous,  and  traced  in  both  directions. 
The  presence  of  the  nerve  of  Wrisberg  has  not  been  satisfactorily 
determined  in  the  cat. 

§  1022.  N.  musculo-cutaneus  s.  cutaneus  externus  (Fig.  104, 
105,  106  ;  Quain,  A,  I,  587  ;  Gray,  A,  674). — The  musculo-cutaneous 
nerve  arises  from  the  ventral  surface  of  the  6th  and  7th  cervical 
nerves.  It  is  also  closely  connected  with  the  N.  medius  (Fig.  106). 
It  passes  almost  directly  toward  the  shoulder  joint,  and  when  near 
the  trocMn  gives  several  filaments  to  the  coracoideus  and  Mceps 
muscles.  It  passes  entad  of  the  long  head  of  the  M.  coracoideus^ 
and  continues  distad  along  the  brachium,  resting  on  the  caudal 
aspect  of  the  biceps.  Opposite  the  Fm.  epitroclileare^  a  small 
branch  is  given  off  which  anastomoses  with  the  N.  medius  through 
the  foramen.  In  the  opncavity  of  the  elbow  it  passes  entad  of  the 
M.  Mceps  to  its  cephalic  aspect.  On  the  antebrachium  it  is  subcu- 
taneous and  extends  along  the  cephalic  border  of  the  arm  parallel 
with  the  JS',  radialis  (Fig.  105).  It  is  distributed  to  both  skin  and 
muscles,  as  the  name  indicates. 

Dissection. — Commence  near  the  shoulder  joint  and  trace  it  first 
centrad  to  determine  its  origin  and  communications,  then  periplierad 
along  its  whole  course.  It  will  be  necessary  to  employ  a  tripod  or 
other  magnifier  in  tracing  the  anastomosis  with  the  median  at  the 
elbow.  On  the  antebrachium  the  nerve  is  very  near  the  surface, 
hence  the  skin  and  fascia  should  be  removed  only  by  degrees  and 
while  keeping  the  nerve  in  sight. 

§  1023.   NN.  subscapulares  (Fig.  104,  105,  106;   Quain,  A,  I, 


li.     CIRCUMFLEX  US.  385 

584  ;  Gray,  A,  673). — There  are  two  of  these  nerves,  or,  if  the  nerve 
of  the  latissimus  be  counted,  three  (Fig.  105,  106).  They  all  arise 
from  the  dorsal  side  of  the  brachial  plexus,  as  shown  in  Fig.  104  and 
106.  The  most  cephalic  one  goes  to  the  M.  subscapular  is,  and  the 
intermediate  one  mostly  to  the  teres.  The  long  subscapular  or 
nerve  of  the  latissimus  passes  caudo-laterad  to  the  M.  laMssimus 
in  connection  with  a  branch  of  the  subscapular  artery  (§  942). 

Dissection. — The  position  of  the  nerves  is  indicated  on  the  fig- 
ures referred  to.  They  may  be  isolated  with  the  tracer  ;  this  should 
be  done  very  carefully  on  account  of  their  position  with  reference 
to  the  other  nerves. 

§  1024.  N.  circumflexus  (Fig.  104,  105,  106  ;  Quain,  A,  I,  584 ; 
Gray,  A,  673). — The  circumflex  nerve  arises  from  a  sort  of  interme- 
diate branch  joining  the  6th,  7th  and  8th  cervical  nerves.  For  a 
short  distance  it  is  in  the  closest  relation  with  the  cephalic  of  the 
subscapular  nerves.  It  passes  nearly  laterad  and  follows  the  cir- 
cumflex artery  as  it  winds  around  the  dorsal  side  of  the  proximal 
end  of  the  humerus  to  terminate  finally  in  the  M.  cla'co-deltoideus  ; 
see  §  941. 

Dissection. — Commence  at  the  point  where  the  nerve  is  crossed 
by  the  musculo-cutaneous,  and  trace  it  first  to  its  origin,  and  then 
to  the  point  where  it  disappears  in  company  with  the  circumflex 
artery.  The  termination  may  then  be  seen  by  lifting  the  cephalic 
edge  of  the  clavo-deltoideus  just  distad  of  the  trocJiiter.  Its  entire 
course  may  be  traced  from  the  periphery  by  cutting  away  the 
muscles. 

§  1025.  N.  medius  s.  medianus  (Fig.  104,  105,  106  ;  Quain,  A,  I, 
590 ;  Gray,  A,  675). — The  median  nerve  in  the  cat  is  formed  by  three 
branches,  shown  in  Fig.  106,  the  brachial  artery  passing  between 
the  cephalic  and  intermediate.  It  follows  the  direction  of  the  artery, 
lying  ectad  of  it  in  most  of  its  course  and  traversing  with  it  the  Fm.. 
cpitrochleare,  where  it  receives  an  anastomosing  branch  from  the  N. 
iiiiiSGulo-cutaneus  (§  1022).  In  the  concavity  of  the  elbow  the  nerve 
passes  entad  of  the  M.  pronator  teres  and  follows  the  general  course 
of  the  bones  of  the  antebrachium  to  the  wrist.  It  furnishes  branches 
to  the  muscles  on  the  ventral  aspect  of  the  antebrachium,  and  espe- 
cially the  N.  interosseus  anterior,  which  accompanies  the  artery  of 
the  same  name  (§  944,  D).  Finally,  it  is  distributed  to  the  struc- 
tures on  the  palmar  aspect  of  the  manus. 

Dissection. — Commence  at  about  the  middle  of  the  brachium 
25 


386  ANATOMICAL     TECHNOLOGY.  » 

and  trace  the  nerve  to  its  origin,  as  shown  in  Fig.  105  and  106. 
Then  it  may  be  followed  peripherad,  but  great  care  should  be 
taken  not  to  injure  the  JSf.  cutaneus  inter nus  or  break  the  anas- 
tomosing lilament  from  the  N.  musculo-cutaneus  (§  1022).  In  the 
concavity  of  the  elbow  the  M.  pronator  teres  should  be  divided  and 
the  nerve  followed  in  the  antebrachium  as  described  for  the  radial 
artery  (§  944). 

§  1026.  N.  musculo-spiralis  (Fig.  104,  105,  106 ;  Quain,  A,  I, 
592 ;  Gray,  A,  679). — The  musculo-spiral  nerve  is  formed  largely 
from  the  8th  cervical  nerve,  although  it  receives  branches  from  the 
7th  cervical  and  the  1st  thoracic  ;  it  is  the  largest  offset  from  the 
brachial  plexus.  It  winds  obliquely  around  the  humerus,  com- 
mencing at  about  its  middle,  being  accompanied  by  the  superior 
profunda  artery  (§  945,  B).  After  reaching  the  cephalic  side  of 
the  brachium,  the  nerve  divides  into  two  parts,  which  are  known  as 
the  radial  and  the  posterior  inter os sens  nerves. 

N.  radialis. — This  is  the  smaller  of  the  two  branches  into  which 
the  musculo-spiralis  divides.  It  becomes  subcutaneous  as  it  emerges 
from  between  the  MM.  ectotriceps^  hracJiialis  and  clavo-deltoldeus 
(Fig.  74),  near  the  distal  end  of  the  brachium.  It  then  follows  tiie 
course  of  the  radius^  remaining  subcutaneous  through  the  whole 
length  of  the  antehracMum.  This  nerve  is  closely  associated  with 
the  musculo-cutaneous.  The  single  large  superficial  r)ein  of  the 
arm  also  follows  its  course.  It  is  partly  cutaneous  in  its  distri- 
bution. 

§  1027.  N.  interosseus  posterior. — This  is  the  larger  of  the  two 
branches  into  which  the  musculo-spiralis  divides.  It  passes  along 
the  dorsal  side  of  the  antebrachium  to  the  wrist.  This  nerve  is 
almost  wholly  muscular  in  its  distribution. 

Dissection. — The  skin  should  be  torn  from  the  dorsal  and  ce- 
phalic sides  of  the  brachium,  then  the  muscles  carefully  cut  along 
the  course  of  the  nerve.  The  J^f.  radialis  will  have  been  exposed 
in  the  study  of  the  musculo-cutaneus.  The  if.  interosseus  may  be 
followed  by  cutting  and  tearing  the  muscles  very  cautiously  with 
a  tracer. 

§  1028.  N.  ulnaris  (Fig.  104,  105,  106;  Quain,  A,  I,  588 ;  Gray, 
A,  677). — The  ulnar  nerve  arises  from  the  8th  cervical  and  the  1st 
thoracic.  It  passes  along  the  brachium  parallel  with  the  brachial 
artery  as  far  as  the  elbow,  and  then  turns  to  the  dorsal  side  of  the 
*3lbow.    It  passes  along  the  dorso-caudal  border  of  the  antebra- 


THE     VAGUS    NERVE.  387 

chium  to  a  point  somewhat  distad  of  its  middle.  Here  it  divides 
into  two  divisions — a  dorsal^  which  winds  around  to  the  dorsal  side 
of  the  man  us,  a  ventral^  which  extends  along  the  ventral  surface  to 
the  palm.  Near  the  distal  third  of  the  antebrachium  the  ventral 
division  sends  a  considerable  branch  to  the  group  of  tactile  hairs 
near  the  hypothenar  eminence  (Fig.  105).  If  the  skin  is  torn  from- 
the  antebrachium  at  this  point,  the  roots  of  the  hairs  will  be  seen 
to  be  similar  to  those  of  the  vibrissse  (Fig.  87,  88).  In  distributiou 
the  ulnar  is  partly  cutaneous,  but  chiefly  muscular. 

Dissection. — The  dissection  of  the  ulnar  nerve  is  very  simple, 
and  needs  no  special  directions. 

§  1029.  N.  thoracicus  posterior — The  external  respiratory  nerve 
of  Bell  (Fig.  104,  105,  106  ;  Quain,  A,  I,  576  ;  Gray,  A,  671).— The 
long  thoracic  or  external  respiratory  nerve  (so  called  because  the 
phrenic  was  called  internal  respiratory)  arises  wholly  from  the  7th 
cervical  near  its  roots.  It  passes  nearly  caudad  to  be  distributed 
to  the  serratus  magnus  muscle.  It  may  be  seen  readily  as  shown 
in  Fig.  105. 

Dissection. — The  rJiomboideus  and  trapezius  muscles  should  be 
divided  and  the  vertebral  border  of  the  scapula  turned  laterad. 
The  nerve  may  then  be  easily  traced  from  its  distribution  to  its 


NERVUS  VAGUS,  s.  PAR  VAGUM,  s.  N.  PNEUMOGASTRICUS,  10th  PAIR. 
(Fig.  101,  105,  107 ;  PI.  II,  Fig.  3,  N.  v.  [x]). 

References,— Qaain,  A,  I,  557  ;  Gray,  A,  660  ;  Hyrtl,  A,  521 ;  Gegenbaur  (Lankester), 
A,  518 ;  Chauveau,  A,  772  ;  Chauveau  (Fleming),  A,  728  ;  Gurlt,  A,  737  ;  Owen,  A,  III, 
159  ;  Milne-Edwards,  A,  II,  340  ;  Leyh,  A,  526  ;  Dalton,  A,  Fig.  482  ;  Stowell,  1. 

%  1030.  The  vagus  or  pneumogmtric  nerve  (x)  arises  apparently  from  the  side  of  the 
medulla,  passes  laterad  and  traverses  the  Fm.  jugulare  in  connection  with  the  glossopha- 
ryngeiis  and  accessorius.  Just  as  it  emerges  from  the  skull  or  just  within  the  foramen, 
it  has  a  ganglion,  the  ganglion  of  the  root,  and  about  1-2  cm.  farther  peripherad  it  pre- 
sents a  second  ganglion,  the  ganglion  of  the  trunk.  The  nerve  passes  along  the  neck  in 
company  with  the  carotid  artery,  and  from  the  ganglion  of  the  trunk  to  a  point  near  the 
1st  rib  is  so  closely  connected  with  the  aympatJiic,  verve  that  the  two  appear  like  one  (Fig. 
107).  The  vagus  enters  the  thorax  mesad  of  the  A.  sternnlis,  extends  caudad  along  the 
ventral  aspect  of  the  A.  subclavia  sinistra  (§  930),  crosses  the  arcus  aortictis,  and  while 
crossing  it  gives  ofE  a  long  branch,  the  N.  laryngeus  recurrens,  which  winds  around  the 
arch  and  extends  cephalad  along  the  trachea  to  the  larynx  (Fig.  107).  The  vagus  then 
passes  caudad  along  the  dorsal  side  of  the  root  of  the  lung.  Slightly  caudad  of  the  root 
of  the  lung  it  divides  into  two  parts  ;  one,  extending  along  the  ventral  side  of  the  oesopha- 
gus, soon  unites  with  a  branch  from  the  right  vagus  (Stowell,  1),  and  the  combined  trunk, 
the  ventral  gastric  nerve,  then  passes  along  the  oesophagus,  penetrates  the  diaphragm  and 


3SS  ANATOMICAL     TECHNO  LOG  T. 

is  distributed  to  the  ventral  aspect  of  the  stomach  ;  the  other  branch  of  the  vagus  winds 
to  the  dorsal  side  of  the  oesophagus,  where  it  is  ji^ined  by  a  small  branch  from  the  right 
vagus.  The  union  of  the  two  forms  the  dorsal  gastric  nerve,  which  penetrates  the  dia- 
phragm on  the  dorsal  side  of  the  oesophagus,  and  is  distributed  to  the  dorsal  aspect  of  the 
stomach  and  especially  to  its  greater  curvature  (Fig.  79). 

The  vagus  supplies  branches  to  the  larynx,  trachea,  heart,  lungs,  (Rsophagus  and  stom- 
ach. Throughout  its  entire  extent  it  is  closely  related  to  certain  spinal  nerves  and  to  the 
sympathicus. 

The  origin,  course  and  distribution  of  the  right  vagus  is  nearly  the  same  as  that  of  the 
left,  except  that  the  recurrent  laryngeal  is  given  off  opposite  the  A.  siibclavia  dextra  (Fig. 
108),  and  winds  around  to  its  dorsal  side  to  reach  the  trachea. 

The  account  of  the  vagus  is  introduced  partly  in  order  to  illustrate  the  origin,  course, 
distribution  and  relations  of  a  peculiar  cranial  nerve,  but  especially  on  account  of  its 
importance  from  an  experimental  standpoint. 

DISSECTION  OF  THE  VAGUS   NERVE. 

§  1031.   Specimen  and  Preparation. —The  specimen  should  be  i/ou7ig  and  lean  (%  1008). 
The  vascular  system  should  be  filled  from  either  the  femoral  or  abdominal  vessels  (§§  352, 
The  same  specimen  is  to  be  used  for  the  sympathic  (§  1042). 


§  1032.  Exposure  and  Dissection. — A  block  should  be  placed 
nnder  the  cat's  neck  so  that  the  head  may  be  slightly  dorsiducted. 
After  parting  the  hair  (§  354),  make  an  incision  from  the  left  exter- 
nal auditory  meatus  to  a  point  opposite  the  tip  of  the  xiphisternum, 
going  about  2  cm.  to  the  left  of  the  ventrimeson.  The  skin  should 
be  reflected  on  both  sides  of  the  incision  for  2-3  cm.  and  held  aside 
with  pins.  Find  the  position  of  the  larynx  and  trachea  (Fig.  88)  by 
pressing  on  the  ventrimeson. 

Make  a  longitudinal  incision  through  the  sterno-masioid  mus- 
cles just  laterad  of  the  trachea,  commencing  near  the  1st  rib  and 
cutting  cephalad  to  the  bulla  (Fig.  57).  It  is  necessary  to  proceed 
with  caution,  however,  in  order  not  to  injure  the  vessels  and  nerves 
on  the  ental  side  of  the  muscle.  Turn  the  cut  edges  of  the  muscle 
aside  and  fasten  them  with  pins.  This  will  e:^pose  three  structures 
lying  parallel  to  the  trachea :— the  carotid  artery,,  which,  being 
injected,  will  be  very  apparent ;  at  the  same  level  as  the  carotid, 
but  laterad  of  it,  the  combined  mgits  and  sympatldc  nerves  ;  and 
finally  between  the  two,  but  somewhat  ventrad,  the  internal  jugii-  j 
lar  tein  (Fig.  101). 

Commence  near  the  middle  of  the  neck  and  follow  the  nerve 
cephalad,  using  the  tracer,  fine  forceps  and  scissors.  Near  the 
bulla  (Fig.  m  and  107,  B),  the  submaxillary  and  lymphatic  glands 
(Fig.  87)  and  the  thyroid  body  (Fig.  101)  must  be  removed.  At 
the  ganglion  of  the  trunk  the  vagus  may  be  separated  from  the  \ 


THE    VAGUS  NERVE.  389 

sympathic  (Fig.  107).  From  the  ganglion  of  the  triink  N.  laryn- 
geus  superior  (Fig.  107,  iV.  L  sup,)  may  be  traced  entad  of  the 
carotid  to  the  larynx. 

§  1033.  N.  hypoglossus  (Fig.  107,  iVl  hpgls.).—A  little  cepha- 
lad  of  the  superior  laryngeal  nerve  this  will  be  seen  crossing  the 
ectal  surface  of  the  carotid  and  extending  to  the  tongue. 

§  1034.  N.  glossopharyngeus  (Fig.  107,  JST.  gph.,  Plate  II,  Fig.  3, 
JV.  gph.  [ix]).— Divide  the  31.  digastricus  (Fig:  101)  near  its  middle 
and  reflect  the  two  ends.  This  will  expose  the  Ijulla^  and  passing 
along  its  caudo-mesal  aspect  will  be  seen  the  small  glossopharyn- 
geal nerve.  From  its  exit  at  the  Fm.  jugulare  (Fig.  57,  §  562),  it 
passes  entad  of  the  carotid  on  its  way  to  the  tongue. 

§  1035.  N.  accessorius. — The  spinal  accessory  may  also  be  seen 
piercing  the  stern o-mastoid  muscle  and  passing  latero-caudad  from 
the  Fm.  jugulare  to  be  distributed  to  the  ental  surface  of  the  claT>o- 
trapezius  muscle  (Fig.  104,  107,  N.  ac). 

§  1036.  The  path  of  the  vagus  through  the  foramen  jugulare  and 
its  relations  with  other  nerves,  also  the  ganglion  of  the  root  (Stow- 
ell,  i),  may  be  made  out  by  nipping  away  the  skull  upon  the 
dorso-lateral  side  of  the  foramen. 

After  the  parts  just  described  have  been  determined,  the  nerve 
should  be  followed  caudad.  Near  the  1st  rib  the  sympathic  inclines 
laterad  (Fig.  107).  The  vagus  passes  into  the  thorax  entad  of  the 
V.  hrachio-ceplialica  (Fig.  101,  109). 

§  1037.  Exposure  of  the  Left  Vagus  in  the  Thorax. — Divide 
the  pectoral  and  other  muscles,  and  costicartilages,  about  1  cm. 
from  the  meson,  and  turn  the  sternum  dextrad,  securing  it  with 
chain  hooks  (§  140)  or  strings.  Tlien  cut  the  left  ribs  with  the  nip- 
pers about  2  cm.  from  their  heads,  and  either  remove  this  part  of 
the  thoracic  wall  entirely  or  pin  it  down  so  that  the  thoracic  cavity 
shall  be  readily  accessible. 

Cut  the  left  brachio-cephalic  vein  and  turn  it  mesad  as  shown  in 
Fig.  107.  The  sternal  artery  (§  935)  may  be  cut  near  the  sternum 
and  pinned  laterad.  Then  the  vagus  may  be  followed  with  the 
tracer,  fine  forceps  and  fine  scissors.  lN"ote  the  phrenic  nerve 
(§  1019),  which  crosses  the  vagus  just  cephalad  of  the  sternal  artery. 
The  phrenic  may  be  easily  traced  along  the  thorax  ventrad  of  the 
root  of  the  lung  to  the  diaphragm,  by  pulling  upon  it  near  where  it 
crosses  the  vagus,  and  turning  the  lungs  to  the  left. 


390  ANATOMICAL     TECHNOLOGY. 

In  tracing  the  vagus,  be  very  careful  to  preserve  all  the  branches 
either  given  off  or  received  by  it.  The  main  nerve  is  so  large  that 
there  is  little  danger  of  injuring  it,  but  its  branches  are  often  very 
small.  It  is  a  great  help  to  pull  the  nerve  in  various  directions  with 
the  fingers  or  forceps ;  then  the  presence  of  branches  or  anasto- 
moses may  be  detected  by  the  tense  lines  extending  from  the  main 
nerve.  There  are  several  of  these  branches  which  leave  or  join  the 
nerve  on  its  way  from  the  1st  rib  to  the  aorta.  One  or  two  of  these 
come  from  the  thyroid  ganglion,  two  or  three  from  the  xertebral 
ganglion.  When  near  the  arch  of  the  aorta,  the  ventral  side  of  the 
vagus  is  crossed  by  the  lesser  cardiac  nerve  on  its  way  to  the  car- 
diac plexus  from  the  vertebral  ganglion  (Fig.  107,  N.  crd.), 

§  1038.  N.  laryngeus  recurrens  s.  inferior  (Fig.  107,  108). — 
Just  before  crossing  the  ventral  side  of  the  aorta,  the  left  vagus  gives 
off  a  large  branch,  which  winds  around  to  the  dorsal  side  of  the  aorta 
and  follows  the  trachea  cephalad  to  the  larynx.  Its  origin  may  be 
readily  determined  ;  but  to  trace  it  on  the  trachea,  the  vessels  should 
be  carefully  removed  in  order  to  expose  the  trachea.  This  should 
be  deferred,  however,  until  the  vagus  is  traced  to  the  stomach,  or 
it  should  be  traced  upon  another  specimen. 

§  1039.  The  vagus  gives  many  branches  to  the  heart  and  lungs 
near  the  point  where  the  nerve  crosses  the  arch  of  the  aorta.  Their 
branches  are  usually  rather  small,  but  their  course  may  be  made 
out  by  pulling  on  the  main  nerve. 

In  tracing  the  vagus  caudad  of  the  arch  of  the  aorta,  the  lung 
should  be  turned  mesad,  so  that  the  nerve  may  be  seen  as  it  passes 
along  the  dorsal  side  of  its  root  (Fig.  107).  In  following  the  nerve 
in  the  remainder  of  its  course,  it  is  especially  desirable  to  draw  it 
tense,  for  in  this  way  is  most  surely  and  easily  determined  the  pres- 
ence of  branches.  Just  caudad  of  the  root  of  the  lung,  the  nerve 
will  be  found  to  divide,  one  part  passing  along  the  dorsal  aspect  of 
the  oesophagus,  and  the  other  remaining  on  its  ventral  surface. 

§  1040.  Follow  the  ventral  branch  (N.  gastricus  ventralis,  Fig. 
103,  107).  About  half  way  between  the  root  of  the  lung  and  the 
diaphragm,  there  will  be  seen  a  branch  joining  it  from  the  right. 
This  can  be  seen  easily  by  pulling  the  nerve  cephalad  and  to  the 
left.  This  branch  is  the  ventral  division  of  the  right  vagus.  The  \ 
combined  trunks  now  pass  along  the  diaphragm  and  penetrate  it 
with  the  oesophagus.     The  diaphragm  may  be  cut  away,  and  then 


I 


THE     VAGUS    NERVE.  391 


if  the  nerve  trunk  be  pulled,  the  fan-like  expansion  of  the  nerve  on 
the  ventral  side  of  the  stomach  may  be  seen. 

§  1041.  N.  gastricus  dorsalis  (Fig.  103,  107).— Now  follow  the 
dorsal  division  of  the  vagus.  It  winds  around  to  the  dorsal  side  of 
the  oesophagus,  and  when  within  about  2  cm.  of  the  diaphragm,  a 
large  brancli  may  be  seen  to  join  it.  This  is  the  dorsal  division  of 
the  right  vagus.  Follow  the  combined  trunk  to  the  diaphragm, 
then  cut  the  diaphragm  so  as  to  expose  the  oesophagus ;  do  this 
carefully,  so  as  not  to  injure  the  nerve.  Now  pull  upon  the  dorsal 
gastric  nerve,  and  its  fan-like  expansion  on  the  great  curvature  of 
the  stomach  will  be  seen,  and  also  a  tense  line  passing  dorso-caudad 
to  the  semilunar  ganglion  of  the  solar  plexus  (Fig.  107,  Ramus 
cm.^  Gng.  smln.).  The  left  semilunar  ganglion  is  at  the  left  of  the 
A.  mesenterica  superior.  It  is  a  pinkish  white  body  not  difficult 
to  distinguish. 

Preparation  of  Fig.  107. — The  arteries  and  veins  were  injected  from  the  abdominal 
aorta  and  postcava  (§§  363,  365) ;  the  skin  was  then  removed  as  shown  in  the  figure,  and 
the  ribs  cut  within  2-3  cm.  of  their  heads  ;  the  costicartilages  were  cut  at  about  the  same 
distance  from  the  sternum,  and  then  the  thoracic  and  abdominal  walls  were  removed. 
The  arm  was  amputated  near  the  middle  of  the  brachium  ;  the  sterno-  and  clavo-rnastoid 
muscles  were  also  removed.  The  sternum  and  Jieart  were  turned  to  the  right,  together  with 
the  hrachio-cephalic  vein.  The  left  lung  was  cut  off  at  its  root  and  removed.  The  vessels 
and  nerves  were  then  isolated  as  directed  above  (§  1008). 

» Explanation  of  Fig.  107. — In  the  description  of  this  figure,  under  the  general  heads, 
ich  are  arranged  alphabetically,  the  special  parts  are  named  commencing  at  the  caudal 
extremity. 

A.  c,  A.  ccEliaca  (§  966).  A.  m.  s.,  A.  mesenterica  superior  (^  967).  A.  ces.,  A. 
cesophagea— One  of  the  oesophageal  arteries.  Aorta  (§  965).  A.  V.  cost.,  A.  V.  cos- 
tales — The  intercostal  arteries  and  veins  (Fig.  103),  A.  brcph.,  A.  brachio-cephalica 
(Fig.  101,  102,  103).  A.  s.,  A.  subclavia  (§  933).  A.  axillaris  (Fig.  105,  §  938).  A. 
sternalis  (§  935).  A.  carotidea — The  left  carotid  artery ;  the  name  is  written  on  the 
trachea  just  mesad  of  the  artery  (Fig.  101,  §  927).  A.  thyr.,  Axis  thyroideus  (§  937). 
A.  1.,  A.  lingualis — The  lingual  artery,  a  branch  of  the  carotid.  A.  fac,  A.  facialis — 
The  facial  artery,  a  branch  of  the  carotid  (Fig.  87).  Adrn.,  Corpus  adrenale — The  adre- 
nal or  suprarenal  body  (§  760).  Cardia— Heart  (§  822).  Costae  (13)— Ribs.  Costae  ster- 
nales  (9).  Dphrg.,  Diaphragma,  (Fig.  90,  §  815).  D.  Stenon.,  Ductus  Stenonia- 
nus — Duct  of  the  parotid  gland  (Fig.  87,  §  780).  Gng.  smnl.,  Ganglion  semilunare — 
The  semilunar  ganglion,  the  largest  ganglion  of  the  solar  plexus  (§  1044).  Gng.  vert., 
Ganglion  vertebrale — The  caudal  cervical  ganglion  of  the  sympathic  (§  1042).  Gng. 
thyr.,  Ganglion  thyroideum  —  The  thyroid  or  middle  cervical  sympathic  ganglion 
(§  1043).  Gng.  crv.  sym.,  Ganglion  cervicale  superius  sympathici — The  superior 
cervical  ganglion  of  the  sympathic  (§  1043).  Gng.  inf.  (vagus),  Ganglion  inferius  vagi 
— The  inferior  ganglion  of  the  vagus,  called  also  the  ganglion  of  the  trunk.  Gl.  (Glan- 
dula)  parotis— The  parotid  gland  (Fig.  87,  §§  773,  779).  Humerus  (Fig.  46,  §  407).  M. 
serratus  mg.  (magnus),  (Fig.  73,  §  664).    M.  teres  (Fig.  75,  §  680).     M.  latis.,  M.  latis- 


392 


ANATOMICAL    TECHNOLOGY. 


Fig.  107.  — The  Va^us  and  Sympathic  Nerves;   x  .5.    A.  Diagram  of  the  Sacral 
Part  of  the  Sympathic  Nerye  ;   x  about  3. 


THE     VAGUS    AND    SYMPATHIC    NERVES,  393 

simus  (Fig.  67,  §  635).  M.  msstr.,  M.  massetericus.  N.  splnch.  minor,  N.  splanch- 
nicus  minor  (Fig.  103,  §  1044).  N.  splnch.  major,  N.  splanchnicus  major,  (Fig.  103, 
§  1044) — Both  splanchnic  nerves  are  seen  to  join  the  semilunar  ganglion  {gng.  smln.). 
N.  gstr.  vnt.,  N.  gastricus  ventralis — The  ventral  gastric  nerve  ;  it  is  formed  partly  by 
the  right  and  partly  by  the  left  vagus,  as  is  also  the  following  (see  Fig.  103,  §  1040). 
N.  gstr.  dor.,  N.  gastricus  dorsalis — The  dorsal  gastric  nerve  (§  1011);  a  large  branch 
{ramus  cm.)  is  seen  to  unite  this  with  the  semilunar  ganglion  {gng.  smln.).  N.  phrn.,  N. 
phrenicus  (Fig.  105,  N:  phrn.).  N.  sym.,  N.  sympathicus — The  sympathic  nerve  in 
the  thorax  (§  1043).  N.  1.  r.,  N.  laryngeus  recurrens — The  recurrent  laryngeal  of  the 
left  side  winding  around  the  aorta  (see  Fig.  108  and  ^  1038).  N.  crd.,  N.  cardiacus — The 
lesser  cardiac  nerve  from  the  sympathic  (Fig.  109).  NN.  thr.  (2  and  4),  NN.  thoracici 
(5  et  6) — The  5tli  and  6th  thoracic  nerves  ;  each  receives  a  branch  from  the  sympathic 
(Fig.  109,  §  1013).  N.  crv.  (6th),  N.  cervicalis  (6th).  N.  crv.  (5th),  N.  cervicalis  (5th) 
— The  phrenic  nerve  is  seen  to  arise  from  this  and  the  preceding  (see  also  Fig,  105,  §  1019). 
N.  vagus  (x),  (Fig.  103,  §§  562,  1030) — The  vagus  and  sympathic  appear  as  a  single  trunk 
in  the  neck,  but  are  easily  separated,  especially  at  their  ganglia  by  the  bulla  {B.)  and  near 
the  1st  rib.  N.  sym.,  N.  sympathicus  s.  N.  sympatheticus — The  great  sympathic  or 
sympathetic  nerve  with  its  ganglia  on  the  left  side  (Fig.  103,  §  1042).  N.  1.  sup.,  N. 
laryngeus  superior  (§  1038).  N.  hpgls.,  N.  hypoglossus  (Fig.  104,  §§  562,  1033,  Plate 
II,  Chapter  X).  N.  ac,  N.  accessorius  (spinalis  xi),  (Fig.  104,  Plate  II,  Chapter  X, 
§§  582,  1035).  N.  gph.,  N.  glossopharyngeus,  ix  (Plate  II,  §§  562,  1034,  Chapter  X).  N, 
aur.  mg.,  N.  auricularis  magnus  (Fig.  87).  CEs.,  CEsophagus  (Fig.  109,  §  801).  Pcv., 
Postcava  (Fig.  101,  §  955).  Ramus  cm.,  N.  ramus  communicans— The  nerve  putting 
into  communication  the  gastric  branch  of  the  vagus  and  the  semilunar  ganglion.  Rx. 
plm.,  Radix  pulmonalis— The  root  of  the  left  lung.  Stomachus  (Fig.  79,  §  735).  Trch., 
Trachea  (Fig.  88,  §  799).  V.  rn.,  V.  renalis  (Fig.  101,  §  959).  V.  m.  s.,  V.  mesenterica 
superior  (§  949) — The  branch  entering  the  V.  m.  s.  as  it  crosses  the  A.  m.  s.  is  the  V.  mesen- 
terica inferior  (§  950).  V.  adrn.-lumb.,  V.  adreno-lumbalis  (Fig.  103,  §  958).  V.  az., 
V.  azygos  (Fig,  91,  107,  §  920).  V.  plm.,  V.  pulmonalis— One  of  the  pulmonary  veins 
just  before  entering  the  left  auricle  (Fig.  91).  V.  brcph.  sin.,  V.  brachio-cephalica  sin- 
istra (§  922). 

Fig.  107,  A. — The  sympathic  of  the  two  sides  in  the  sacral  and  part  of  the  coccygeal 
regions,  showing  the  fusion  or  close  connection  of  the  ganglia  and  their  connection  with 
the  myelencephalic  nerves  ;  x  about  3. 

Preparation  of  Fig.  107,  A. — The  ventral  half  of  the  pelvic  girdle  (§  455)  was  cut 
away  with  nippers,  and  then  all  the  pelvic  viscera  were  removed.  The  sympathic  nerves 
were  found  resting  on  the  lumbar  vertebrae  by  divaricating  the  psoas  muscles.  The  nerves 
were  carefully  traced  to  the  sacral  and  coccygeal  region,  and  their  anastomoses  with  the 
spinal  nerves  and  the  fusion  of  the  ganglia  were  exposed  by  removing  muscle,  connective 
tissue  and  the  middle  sacral  artery  with  fine  forceps,  scis.sors  and  tracer,  using  also  the 
tripod  magnifier  whenever  the  branches  became  so  small  as  to  be  in  danger  of  injury  from 
not  being  distinctly  seen. 

Explanation  of  Fig.  107,  A. — Anst. — Anastomosis  of  the  two  ganglia.  Gng.  (gan- 
glion) impar — A  single  ganglion  formed  by  the  fusion  of  those  of  the  two  sides  ;  in  the 
one  just  cephalad  the  ganglia  are  not  completely  fused,  but  connected  by  anastomosing 
fibers.  Gng.  (ganglion)  impar  (ist) — The  1st  fused  ganglion  of  the  sympathic  ;  it  is 
opposite  the  2d  sacral  vertebra  (§  458).  N.  myen.,  N.  myelencephalicus — Four  myelen- 
cephalic or  cerebro  spinal  nerves  with  their  anastomosing  branches  from  the  sympathic. 
tsym.,  N.  sympathicus — The  nerves  of  the  two  sides  approaching  each  other  on  the 


394 


ANATOMICAL   TECHNOLOGY, 


Preparation  of  Fig.  108.— The  vagus  and  sympatliic,  together  with  the  arteries,  were 
isolated  as  directed  above  (§  1003).  The  left  cardiac  nerves  from  the  thyroid  and  vertebral 
ganglia  frequently  pass  ventrad  of  the  vagus,  as  shown  in  Fig.  107,  and  those  of  the  right 
side  often  pass  to  the  heart  along  the  ventral  side  of  the  blood  vessels  instead  of  as  here 
shown ;  see  Quain,  A,  I,  633. 

The  figure  is  meant  to  illustrate  the  origin  and  course  of  the  recurrent  laryngeal  nerve 
on  the  two  sides — (A)  representing  the  right  side,  with  the  recurrent  winding  around  the 
A.  subdavia  dextra,  and  (B)  the  left  side,  with  the  recurrent  nerve  winding  around  the 
arch  of  the  aorta. 


Fig.  108. — The  Recurrent  Laryngeal  Nerves,  Ventral  View,  (Stowell,  1); 

X  about  1. 

Explanation  of  Fig.  108. — The  abbreviations  are  the  same  in  the  two  figures. 

Aorta,  az.  (§  928).  A.  brcph.,  A.  brachio-cephalica,  az.  (§  943).  A.  subcl.,  A.  sub- 
davia (§  933).  A.  carotid.,  A.  carotidea.  A.  stern.,  A.  sternalis  s.  mammaria 
interna.  G.  vert.,  Ganglion  vertebrale  (§  1043).  G.  thyr..  Ganglion  thyroideum 
(§  1043)    N.  vagus  (§  1030).     N.  1.  r  ,  N.  laryngeus  recurrens  (§  1038). 


NERVUS  SYMPATHICUS  s.  SYMPATKETICUS.    (Fig.  90,  101, 
103,  105,  107,  108,  109). 

References.— Quain,  A,  I,  626  ;  Gray,  A.  696;  Hyrtl,  A,  572  ;  Gegenbaur,  A,  522  ; 
Ohauveau,  A,  328  ;  Chauveau  (Fleming),  A,  781  ;  Gurlt,  A,  767,  774  ;  Owen,  A,  III,  181  ; 
Milne-Edwards,  A,  II,  331  ;  Leyh,  A.  550. 

§  1042.  The  sympathic  nervous  system  as  a  whole  comprises  a  central  system  con- 
sisting of  a  double  chain  of  ganglia  extending  alon^j  the  ventral  side  of  the  spinal  column. 
The  two  chains  also  extend  into  the  head  and  into  the  tail.     The  ganglia  are  connected  by 


IB  NN.     SPLANCHNICI.  395 

Intervening  nerves  and  gfive  rise  to  nervous  brandies  which  are  distributed  to  the  viscera 
and  blood  vessels.  Besides  the  chain  of  ganglia,  the  sympathic  nerves  may  have  ganglia 
developed  upon  them  at  almost  any  point  in  their  course.  The  various  parts  of  the  sym- 
pathic  are  intimately  associated  with  each  other  and  also  with  the  cerebro-spinal  nervous 
system.  So  close  is  this  connection  that  some  authors  consider  the  sympathic  as  belong- 
ing to  tiie  peripheral  part  of  the  cerebro-spinal  system  (Quain,  A,  I,  519). 

There  are  nominally  as  many  pairs  of  sympathic  ganglia  as  vertebrae,  except  in  the 
cervical  region  and  rarely  also  in  other  regions.  From  each  ganglion  passes  a  branch  to 
the  corresponding  spinal  nerve  (Fig.  107,  109). 

§  1043.    Specimen^   Preparation  and  Dissection.  —  The  same 
specimen  may  be  emj)loyed  as  for  the  vagus,  and  it  slionld  be  pre- 
pared in  precisely  the  same  manner  (§  1030).    The  exposure  is  also 
-the  same,  and  the  method  of  dissecting  the  nerves  (§  1031). 
p     Nearly  dorsad  of  the  ganglion  of  the  trunk  of  vagus  is  the  sim- 
ilar, fusiform,  superior  cervical  ganglion  of  the  sympathic.     It 
(aay  be  carefully  isolated  ;  then,  by  carefully  tearing  the  sheath  of 
lie  combined  vagus  and  sympathic,  the  two  may  be  separated  in 
tie  neck.     About  1  cm.  from  the  1st  rib  the  sympathic  inclines  lat- 
rad,  and  very  near  it  there  appears  in  most  subjects  a  small  gan- 
glion, the  thyroid  or  middle  cervical  ganglion  (Fig.  107,   Gng. 
thyr..  Fig.  108).     Pull  the  nerve,  and  it  will  be  found  to  divide 
into  two  parts,  one  of  which  passes  dorsad  and  the  other  ventrad  of 
the  A.  subclaim  la  (Fig.  109).     Cut  the  axillary  artery  and  turn  it 
mesad.     The  two  nerves  may  then  be  followed  to  their  termination 
in  the  ganglion  vertebrale  or  the  inferior  cervical  ganglion  just 
caudad  of  the  1st  rib  (Fig.  107,  Gng.  vert,  108,  109).     Pull  upon  the 
^fcerve  and  make  out  the  branches  passing  from  this  ganglion.     They 
Bare   shown  in  Fig.   107,   108  and  109.     After  these  branches  are 
traced,  tear  away  the  pleura  and  follow  the  sympathic  chain  along 
the  thorax.    Note  that  there  is  a  ganglion  for  each  vertebra,  and 
that  each  ganglion  communicates  with  the  corresponding  spinal 
nerve  (Fig.  107). 

§  1044.  NN.  splanchnici.— The  sympathic  ganglion  about  oppo- 
site the  last  rib  is  somewhat  larger  than  those  preceding  it,  and  there 
is  given  off  a  branch,  the  N.  splanchnlcus  major,  which  passes 
caudad  and  slightly  ventrad  and  penetrates  the  diaphragm.  The 
diaphragm  should  be  cut,  the  abdomen  well  opened  and  the  viscera 
turned  to  the  right ;  then  by  pulling  upon  this  nerve  it  will  be  seen 
to  move  the  semilunar  ganglion,  showing  that  it  joins  that  body. 
Now  follow  the  sympathic  from  the  origin  of  the  great  splanchnic. 
It  becomes  more  nearly  mesal  in  position,  and  when  near  the  dia- 


396  ANATOMICAL    TECHNOLOGY. 

phragm  gives  off  another  branch,  the  N.  splancJinicus  minor.  This 
also  penetrates  the  diaphragm  and  joins  the  semilunar  ganglion 
(Fig.  90,  107). 

§  1045.  Ganglion  semilunar'e  (Fig.  90,  107).— The  semilunar 
ganglion  belongs  to  the  so  called  solar  plexus  of  nerves,  a  network 
of  nerves  formed  partly  from  the  vagus  (§  1041),  but  mostly  from 
the  sympatMc.  The  ganglion  is  a  slightly  pinkish  body  situated 
laterad  of  the  origin  of  the  superior  mesenteric  and  cceliac  arteries., 
as  shown  in  Fig.  107,  and  very  near  the  adrenal  body.  It  is  quite 
tough,  and  when  grasped  and  pulled  the  nerves  may  be  seen  spread- 
ing out  in  all  directions  like  the  rays  of  the  sun. 

§  1046.  The  abdominal  sympathic. — In  order  to  follow  the 
sympathic  in  the  abdomen,  the  blood  vessels  should  be  removed. 
The  nervous  cords  of  the  two  sides  closely  approach  each  other,  so 
that  both  may  be  traced  at  once. 

The  caudal  part  of  the  sympathic  is  partly  shown  in  Fig.  107,  A, 
and  directions  for  tracing  it  are  given  under  the  preparation  of  this 
figure. 

Preparation  of  Fig-.  109. — The  arteries  were  injected  with  red  and  the  veins  with  blue 
plaster  (§§  363,  363).  The  sternum  was  removed,  and  the  thyroid  and  vertebral  ganglia 
of  the  sympathic  and  their  branches  isolated  as  directed  above  (§  1008).  The  thyroid  gan- 
glion of  the  right  side  was  displaced  somewhat  dextrad,  the  vertebral  ganglion  of  the  left 
side  drawn  dorsad,  and  the  muscles  removed  from  the  vertebra  and  the  pleura  and  con- 
nective tissue  from  the  other  parts.  The  oesophagus  was  slightly  distended  with  cotton 
and  the  two  roots  of  the  myelonal  nerves  slightly  separated  and  held  apart  with  cotton. 
The  preparation  was  hardened  and  preserved  in  alcohol  (§  286). 

Explanation  of  Fig.  109. — A.  sbclv.  sin.,  A.  subclavia  sinistra.  A.  sbclv.  dext., 
A.  subclavia  dextra — The  right  subclavian  is  shown  in  two  places  as  if  it  were  double  ; 
the  artery  is  not  double,  but  is  shown  in  its  natural  position  and  also  displaced  in  order  to 
more  clearly  indicate  the  ring  of  the  sympathic  {ansoR  s.  annulus  Vieussenii)  surrounding 
it;  see  Fig.  108  and  Foster,  A,  Fig.  37.  A.  c,  A.  carotidea  (§  900).  A.  sternalis— On  the 
left  the  name  is  written  on  the  artery.  A,  thyr.,  A.  vertebralis — By  an  inadvertence  the 
wrong  abbreviation  was  used.  The  artery  is  shown  on  the  right  dorsad  of  the  origin  of 
the  A.  sternalis. 

Alba— The  white  substance  of  the  myelon.  It  is  dotted  to  indicate  the  cut  ends  of 
nerve  fibers  (§  1048). 

Cn.  centralis— The  central  canal  of  the  myelon  ;  see  Chapter  X,  Fig.  112,  A. 

Centrum— The  centrum  or  body  of  the  2d  thoracic  vertebra  (§  462). 

Cinerea— The  gray  or  ganglionic  substance  of  the  myelon  (§  1047).     It  is  left  white  iil| 
the  figure,  and  appears  something  like  a  letter  //in  the  interior  of  the  myelon  (§  998). 

F.  dms.,  Fissura  dorsimesalis— The  dorsimesal  (posterior)  fissure  of  the  myelon. 

F.  vms.,  Fissura  ventrimesalis — The  ventrimesal  fissure  of  the  myelon.  It  is  directlj 
opposite  the  dorsal  fissure,  and  the  two  divide  the  myelon  nearly  in  half  (§  998). 


TRANSECTION    OF    THE    THORAX. 


397 


Gng.  thyr.,  Ganglion  thyroideum — Tlie  thyroid  or  middle  cervical  g-anglion  of  the 
sympathic  (Fig.  107,  108,  §  1043). 

Gng.  vrt.,  Ganglion  vertebrale — The  vertebral  or  inferior  cervical  ganglion  of  tb.; 
sympathic  (Fig.  107,  108,  §  1043). 

Myelon — Tbe  myelon  or  spinal  cord  is  the  part  of  the  central  nervous  system  situated 
within  the  neural  canal  (Fig.  104,  §  479), 

MM.  Ig.  colli — The  longiis  colli  muscles. 

N.  thr.  (ist) — The  first  thoracic  or  dorsal  nerve.  The  abbreviation  is  written  on  the 
ventral  primary  division.    Centrad  of  the  abbreviation,  the  dorsal  primary  division  is  seen 


"^c^^VV.lre^A.. 


Fig.  109.— Transection  of  the  Thorax,  showing  the  Origin  of  a  Pair  of  Spinal 
Nerves  and  the  Relations  of  the  Sympathic  and  Cerebrospinal  Systems  ; 
Cephalic  View  :   x  1 .5. 


to  join  the  ventral,  and  the  trunk  is  formed  by  the  union  of  the  dorsal  and  ventral  nerve 
roots  from  the  myelon  (§  1007). 

N.  thr.  (2d),  N.  thoracicus  (2d) — The  second  thoracic  nerve,  showing  the  ramus  com- 
municans  connecting  it  with  the  vertebral  ganglion. 

N.  sym.  (cd.)  i,  N.  sympathicus  (caudalis)— The  sympathic  nerve  extending  caudad 
of  the  vertebral  ganglion  in  the  thorax  (Fig.  107,  §  1043). 

Ramus  communicans  2 — The  communicating  branch  between  the  vertebral  ganglion 
of  the  sympathic  and  the  2d  thoracic  myelonal  nerve. 


398  ANATOMICAL    TECHNOLOGY. 

Ramus  communicans  3 — The  branch  or  ramus  connecting  the  vertebral  ganglion  of 
the  sympathic  witli  the  1st  thoracic  myelonal  nerve, 

Rm,  crv.  4  (7),  Ramus  communicans  cervicalis  (7th) — The  branch  connecting  the 
7th  cervical  nerve  with  the  vertebral  ganglion. 

N.  crd.  5,  Nervus  cardiacus  minor— The  lesser  cardiac  nerve  from  the  vertebral 
ganglion.  Tlie  heart  receives  several  filaments  from  the  vertebral  and  thyroid  ganglia, 
but  only  this  large  one  is  shown. 

N.  sym.  (cph.)  6,  N.  sympathicus  (cephalicus)— The  sympathic  nerve  extending 
cephalad  of  the  thyroid  ganglion  along  the  neck.  It  is  somewhat  displaced  to  the  right ; 
see  Fig.  107. 

N.  sym.,  N.  sympathicus — The  cut  end  of  the  sympathic  nerves  of  the  two  sides, 
showing  their  relations  to  other  parts.  That  of  the  left  side  {N.  sym.)  is  on  the  left  of  the 
corresponding  carotid  artery,  while  the  one  on  the  right  {N.  s.)  is  dorsad  of  the  right 
carotid  and  very  close  to  the  vagus. 

N.  v.,  N.  vagus — The  cut  ends  of  the  vagus  or  pneumogastric  nerves,  showing  their 
relations. 

N.  phrn.,  N.  phrenicus — The  cut  ends  of  the  phrenic  nerves,  showing  their  relations 
to  the  other  structures. 

CEs.,  (Esophagus  (Fig.  103,  107,  §  798) — The  oesophagus  is  seen  to  be  somewhat  to 
the  left  of  the  meson  and  dorso-sinistrad  of  the  trachea.  It  is  rei)resented  as  somewhat 
contracted,  hence  the  wavy  outline  of  the  mucous  membrane, 

Rx,  et  Gng.  dorsalis,  Radix  et  Ganglion  dorsalis — The  dorsal  (posterior)  root  of 
the  1st  pair  of  myelonal  nerves  with  its  ganglion.  (The  adjective  dorsalis  belongs  only  to 
radix,  hence  the  feminine  form.) 

Rx.  vnt..  Radix  ventralis — The  ventral  (anterior)  root  of  the  1st  pair  of  myelonal 
nerves  (§  1007). 

Spina  neu.  thr.  (2),  Spina  neuralis  thoracica  (2) — The  2d  neural  thoracic  spine. 

Trachea — The  trachea  is  represented  as  slightly  contracted  so  that  the  cartilaginous 
rings  overlap  somewhat. 

VV.  brcph.,  VV.  brachio-cephalicae — The  cut  ends  of  the  two  brachiocephalic  veins 
(Fig.  101,  §'932). 

§  1047.  Obvious  Structure  of  Nervous  Tissue. — Nervous  tissue  is  obviously  of  two 
kinds  : — (A)  Alba  {ichite  matter).  This  is  found  in  the  central  nervous  system,  where  it 
has  a  dense,  lusterless  white  appearance,  but  principally  in  the  nerves  (§  995),  where  it  is 
white  and  glistening ;  the  nerve  also  has  a  wavy  or  crimped  appearance  when  relaxed. 
The  nerves  themselves  have  something  of  the  same  obvious  structure  as  striated  muscle 
(§  704\  that  is,  a  more  or  less  cylindrical  fasciculus,  surrounded  by  a  sheath  (epineumim), 
and  this  mass  in  turn  being  composed  of  smaller  bundles  (funiculi)  each  funiculus  having 
its  special  sheath  (perineurium,  neurilemma). 

(B)  Gray  matter.  The  gray  nervous  matter  is  soft,  so  that  it  is  easily  crushed  in  the 
hand  ;  in  color  it  is  of  a  delicate  gray  or  reddish  brown,  and  is  collected  in  masses  (§  994), 
the  largest  being  in  the  brain  and  myelon  (§  997). 

g  1048.  Microscopic  Structure  of  Nervous  Matter.— (A)  White  matter  (alba).  Each 
funiculus,  like  the  fasciculus  of  a  striated  muscle,  is  composed  of  a  variable  number  of  cyl- 
indrical fibers  which  are  of  two  kinds :— (1 )  Medullated,  composed  of  three  parts,  viz.,  a 
primitive  sheath  somewhat  comparable  to  the  sarcolemma  of  the  muscle  fiber  (§  705) ;  it 
has  a  wavy  outline  and  presents  nuclei :  Myeline  or  white  substance  of  Schwann,  this  is  a 
white  fatty  substance  just  within  the  primitive  sheath  ;  it  is  interrupted  at  regular  intervals 


•       STRUCTURE    OF    NERVOUS    MATTER.  399 

(1-3  mm.),  forming  the  nodes  of  Ranvier  :  Axis  hand,  band  axis,  axis  cylinder  ;  this  forms 
the  central  part  of  the  nerve  fiber;  it  is  continuous,  subcylindrical,  grayish,  rather  tena- 
cious, finely  Hbrillated  and  with  straight  outline.  The  axis  cylinder  is  the  essential  part 
of  the  nerve,  and  is  the  only  part  found  at  its  origin  and  termination.  Medullated  nerves 
neither  give  nor  receive  anastomoses  except  very  near  their  termination.  In  cross  sec- 
tion, a  bundle  of  nerve  fibers  appears  like  a  bunch  of  lead  pencils,  the  band  axis  corre- 
sponding to  the  lead.  (2)  Non-medullated  fibers.  These  are  of  a  pale  gray  appearance, 
owincr  to  the  absence  of  the  myeline.  They  possess  a  nucleated  sheath  and  an  axis  cylin- 
der like  the  medullated  fibers,  but  differ  from  them  in  the  absence  of  the  medullary  sheath 
and  from  the  fact  that  they  anastomose  frequently  throughout  their  entire  course ;  Ran- 
vier, A,  776. 

(B)  Gray  matter.  Gray  matter  is  composed  of  an  interlacing  network  of  nerve  fibers, 
peculiar  connective  tissue  {neuroglia)  and  nerve  cells,  the  latter  being  the  characteristic 
feature.  The  nerve  cells  of  the  brain  and  myelon  apparently  possess  no  proper  sheath, 
and  present  two  forms,  viz.,  (1)  cells  containing  a  nucleus  and  nucleolus,  surrounded  by 
the  gray  or  reddish  brown  protoplasm  which  gives  off  one  or  more  processes,  giving  rise 
to  the  so  called  multipolar  cells,  one  or  more  of  the  poles  being  continued  as  the  band  axis 
of  a  nerve  fiber;  (2)  cells  much  smaller  than  the  preceding,  composed  apparently  of  only 
a  nucleus  and  nucleolus.  The  nerve  cells  of  the  ganglia  possess  a  proper  sheath,  which 
is  merely  an  expansion  of  the  primitive  sheath  of  a  nerve  fiber.  Typically,  these  cells 
are  pyriform  and  possess  a  pole  at  each  end  which  is  continued  into  a  nerve  fiber. 
Strieker,  A,  116 ;  Quain,  A,  II,  125. 


CHAPTER    X. 

ENCEPHALON— THE     BRAIN. 

GENERAL  CONSIDERATIONS — NAMES  OF  THE  PRINCIPAL  PARTS  OF  THE  AMPHIBIAN  BKATN 
— DIAGRAMS  OF  AN  IDEAL  SIMPLE  BRAIN— EXAMINATION  OF  THE  BRAINS  OF  THE 
FROG  AND  MENOBRANCHUS— REMOVAL  OF  THE  CAT'S  BRAIN — MACROSCOPIC  VOCABC- 
LARY — DESCRIPTION  OP  FIGURES  AND  PLATES— DISSECTION  OF  THE  BRAIN — 
SYNONYMS  AND  REFERENCES — FISSURES  AND  GYRL 

§  1049.  General  Considerations.— JDeJlnit Ion.— Exclnding  Am- 
phioxus^  whose  brain  is  peculiar  and  apparently  incomplete,  the 
vertebrate  encephalon  may  be  defined  as  the  enlarged,  differenti- 
ated and  incompletely  segmented  cephalic  portion  of  the  myelen- 
cephalon  (cerebro-spinal  axis),  contained  within  the  cranium. 

The  junction  of  the  brain  proper  with  the  myelon  proper  (§  1006,  Fig-.  104)  is  formed 
by  the  part  commonly  called  medulla  (oblongata),  but  metencephaloii  by  Qiiain  (A,  II,  755), 
and  in  the  present  work.  By  its  obvious  characters  and  real  structure  the  medulla  is 
only  a  modified  continuation  of  the  myelon  (Strieker,  A,.  758-764,  Spitzka,  1,  46),  and 
Wyman  describes  it  (34,  7)  as  a  division  thereof;  most  writers,  however,  regard  it  as  a 
part  of  the  brain,  and  this  is  practically  the  more  convenient  way. 

§  1050.  Importance  and  Difficulty  of  the  Study  of  the  Brain. — An  acquaintance  with 
the  obvious  features,  the  intimate  structure  and  the  functions  of  the  brain  is  desired  by 
not  only  the  physician  and  the  practical  veterinarian,  but  also  by  the  systematic  zoologist, 
the  comparative  anatomist,  the  physiolo^st  and  the  psychologist. 

The  nature  and  extent  of  the  obstacles  to  the  acquisition  of  this  knowledge  are  most 
fully  appreciated  by  those  who  have  advanced  the  farthest  in  its  pursuit  ;  some  idea  of 
them  may  be  gained  from  any  recent  compendium  by  an  original  investigator  in  cither 
of  the  branches  of  inquiry  above  indicated  (Quain,  A,  II ;  Strieker,  A  ;  Ferrier,  A). 

Deferring  for  the  present  any  considerations  of  the  histology  and  functions  of  the 
mammalian  brain,  its  mere  topography  is  far  from  easy  to  understand. 

§  1051.  Methods  of  Studying  the  Brain.— ^hQ  brain  is  com- 
monly figured  and  described  as  a  fibrous  and  cellular  mass  pene- 
trated here  and  there  by  inconsiderable  cavities.  Little  attention  is 
paid  to  the  membranes  which  line  these  cavities  and  invest  the 
entire  organ.     Stress  is  laid  upon  its  complex  structure  and  remark- 


COMMEISTTAEY    Ols    CHAPTER    X. 

Since  the  publication  of  the  first  edition  of  this  work,  there  have 
appeared  reasons  for  modifying  the  account  of  the  brain  in  the 
following  respects :  (a)  The  structure  of  a  few  parts  ;  {b)  the  mode 
of  preparing  the  brain ;  (c)  the  names  of  certain  parts ;  (d)  the 
general  constitution  of  the  brain  ;  {e)  the  general  system  of  nomen- 
<'lature. 

(A)  The  structure  of  a  few  parts.— (1.)  Th^  conarium  of  Amphibia. — The  small, 
vascular  body  which  lies  between  the  caudal  parts  of  the  cerebral  hemispheres  (§  1095)  has 
been  described  usually  as  the  conarium  (pineal  body).  Wyman  was  in  doubt  respecting 
the  homology  (34-,  11),  and  the  recent  observations  of  Osborn  {1,2,  263-270)  show  that 
this  body  is  truly  a  plexus  (supraplex)  ;  that  immediately  caudad  of  it  is  a  hitherto  unde- 
scribed  commissure  {supracommismire  or  commissura  habenarum)  \  and  between  this  and 
the  postcoramissure  is  an  insignificant  and  commonly  overlooked  remnant  of  the  stalk 
of  the  conarium,  that  body  itself  remaining  ectad  of  the  cranium.  In  the  present  work, 
therefore,  on  pp.  420  and  422,  the  name  crnmrium  should  be  replaced  by  supraplex. 

(2.)  Pseudoccele.—ln  the  present  work  (§§  1297,  1315,  1162)  it  is  stated  that  the  two 
halves  of  the  septum  are  in  contact,  and  that  the  so-called  "  fifth  ventricle  "  of  the  human 
brain  is  wanting  in  the  cat.  This  statement  was  based  upon  the  examination  of  alcoholic 
specimens,  and  it  is  possible  that  there  is  some  variation  in  this  respect.  From  a  more 
recent  examination  of  a  fresh,  adult  brain,  and  from  the  transection  of  a  foetal  head, 
the  senior  author  has  described  and  figured  the  pseudocoele  (50,  459,  Fig.  49.) 

(3.)  Thalamus. — In  extension  and  partial  qualification  of  the  statements  on  p.  490  as  to 
the  appearance  of  the  thalamus  as  part  of  the  floor  of  the  proccele,  see  Wilder,  56,  460. 

(B)  Modes  of  Preparation.— (1.)  Entoccdian  alinjection. — The  injection  of  the  cat's 
coelise  with  alcohol  was  recommended  in  the  first  edition  (§  1124).  It  has  since  proved  very 
useful  with  the  Amphibian  and  human  brain,  as  described  by  the  senior  author  {HO,  233- 
234).  With  the  frog  or  Necturus  {Menobranchus),  the  quantity  of  alcohol  required  is  so 
small  that  the  injection  may  be  made  with  a  small  syringe  or  even  with  a  dropping-tube 
(§  1445).  The  tip  of  the  tube  may  be  applied — not  introduced — at  the  lura  (infundibular 
foramen)  or  at  an  orifice  made  in  either  hemisphere  or  in  the  metacoele,  according  to  the 
part  of  the  brain  which  is  to  be  particularly  studied.  The  brain  (preferably  supported 
upon  part  of  the  head)  should  be  placed  in  water  for  a  few  moments  before  the  injection 
is  made  ;  afterward  in  95  per  cent,  alcohol.  Entoccelian  alinjection  of  mammalian 
brains  is  most  readily  accomplished  through  the  lura,  and  by  using  either  a  rubber 
bulb-syringe,  and  repeating  the  operation,  or  a  "constant  pressure  apparatus"  so  as  to 
secure  the  continuous  alinjection  described  in  the  paper  above  named  {50,  234).  The 
alcohol  should  simply  flow  into  the  ccelise  without  exerting  any  more  pressure  than  may 
keep  the  parietes  at  their  normal  distance  from  each  other, 

(2.)  Arterial  alinjection  should  be  preceded  by  washing  out  the  blood  of  the  organ  with 
weak  (25-40  per  cent.)  alcohol  injected  from  the  basilar  or  a  vertebral  artery.  Then  the 
canula  is  to  be  secured  in  that  artery  and  all  the  other  cut  arteries  tied.  The  alcohol  should 
be  strong  (90-95  per  cent.)  and  the  reservoir  placed  at  least  1  meter  above  the  brain  in  order 
to  obtain  the  needed  pressure.  In  warm  weather  the  tube  conveying  the  alcohol 
should  pass  through  an  ice  box.     The  same  process  of  continuous  alinjection   may  be 


400^  ANATOMICAL    TECHNOLOGY. 

applied  to  entire  liuman  heads  or  entire  animals,  (Wilder,  (>1),  which  should  be  kept  at  a 
low  temperature — as  in  an  ice-chest — during  the  operation. 

(3.)  Starch  injection  (by  the  process  described  on  the  leaf  interpolated  between  pp.  140 
and  141)  is  to  be  preferred  to  the  injection  with  plaster,  sagjrested  on  p.  436.  For  permanent 
preparations  of  starch-injected  brains,  the  cut  ends  of  all  the  larger  vessels  must  be  tied 
to  prevent  the  escape  of  the  starch, 

(4.)  Injection  of  Midler's  Fluid. — This  liquid  (potassium  dichromate  63  grams,  sodium 
sulphate  25  grams,  water  2500  cc),  stains  the  cinerea  darker  than  alba,  and  is  therefore 
better  for  preserving  the  brain  for  sections  in  which  it  is  necessary  to  distinguish  alba 
and  cinerea.  The  brain  may  be  hardened  by  simple  immersion,  by  arterial  or  coelian 
injection  and  immersion,  or  by  a  combination  of  these  methods.  After  10  to  40  days  the 
brain  is  placed  in  50  per  cent,  and  then  in  75  per  cent,  alcohol,  each  for  three  days.  It  is 
finally  preserved  in  alcohol  of  80  to  95  per  cent. 

(C)  The  names  of  certain  parts. — Hippocamp  (§  1243). — In  view  of  the  considera- 
tions presented  by  Spitzka  (20),  especially  as  to  the  probability  that  the  occurrence 
oihypocampe  in  Vicq  d'Azyr  was  due  to  the  ease  with  which  the  syllable  ^i/;^,  hastily 
written,  may  be  mistaken  by  a  printer  for  hyp,  the  senior  author  has  withdrawn  {03 ,  356) 
the  term  hypocampa.  In  the  present  work,  therefore,  in  place  of  hyiwcampa,  and  Jiypo- 
campcB,  hippocampus  and  hippocampi  or  hippocampalis  are  to  be  employed.  The  English 
paronyms  hippocamp  and  hippocampal  are  to  be  preferred. 

Fornicolumn. — This  mononymic  equivalent  for  columna  fornicis  (§  1207),  is  employed 
by  the  senior  author  (56*,  514,  Fig.  54  ;  (>3,  327,  Fig.  3). 

Fornicommissure. — This  was  proposed  by  the  senior  author  {03,  327,  Fig.  3)  as  a 
mononymic  designation  of  the  mesal  band  of  the  fornix.  In  the  cat  it  differs  little  from 
the  lateral  portions,  but  in  man  its  caudal  portion  is  so  thin  as  to  be  sometimes  overlooked 
entirely.  It  was  named  by  Reichert,  {A,  Fig.  34,  35,  "  W^")  commissura  corporis  fornicis, 
or  commissur  des  Gewolbes  (pp.  70, 158,  159).  The  name  commissura  fornicis  in  the  present 
work  (§  1210)  should  be  commissura  columnarum  fornicis  (Reichert,  70,  161,  Fig.  35, 
"  W  "  ;  Wilder,  03,  375,  note). 

Lura. — The  descriptive  dionym,  Foramen  infundibuU  (§  1237),  applied  herein  to  the 
orifice  at  the  base  of  the  brain  after  removal  of  the  infundibulum,  is  to  be  replaced  by  the 
mononym  lura,  proposed  by  the  senior  author  {03,  234). 

Metepencephal,  metepicoele,  oblongata,  postohlongata  and  predblongata. — See  (D). 

Pala. — This  name  is  proposed  for  the  lamella  near  the  tip  of  the  medicornu,  con- 
stituting the  transition  between  the  ordinary  nervous  parietes  of  the  cavity  and  the 
membranes  which  close  the  rima  (§  1312).  It  is  described  and  figured  by  the  senior  author 
{50,  376,  Fig.  48). 

Preoptic  lobe  (Lat.  prcBopticus). — In  the  first  edition  the  cephalic  pair  of  mesencephalic 
lobes  were  called  optic  and  the  caudal  pair  postoptic.  It  seems  better,  as  suggested  by 
the  senior  author  {50,  177,  Fig.  12)  to  designate  the  cephalic  pair  by  the  specific  name 
'preoptic,  and  retain  optic  for  the  entire  group  of  mesencephalic  elevations,  preoptic,  post- 
optic,  and,  in  some  reptiles,  interoptic. 

Prosoccde  (Lat,  prosoccdia). — This  term,  obviously  correlated  with  prosencephal  and 
first  employed  by  T.  J.  Parker,  (A  ;  2),  designates  the  entire  prosencephal ic  cavity, 
irrespective  of  its  subdivision  with  most  vertebrates  into  aula,  portas,  procceles  (lateral 
ventricles)  and  rhinocoeles  (olfactory  ventricles).  In  like  manner,  mesocode  designates  the 
entire  mesencephalic  cavity,  whether  it  is  comparatively  simple,  as  in  mammals,  or 
composed  of  a  mesal  iter,  connected  by  pylas  with  lateral  optocoeles  (optic  ventricles),  as  in 
Birds  and  anourous  Amphibia. 

Supracommissure. — This  name  is  preferred  to  commissura  habenarum  (§  1211).  The  part 


COMMENTARY  ON  CHAPTER  X,  400c 

lias  been  observed  in  the  lamprey  and  in  Amphibia  (Osbom,  2,  268),  and  the  name  has 
been  adopted  by  the  writer  last  named  {2,  268,  4:). 

(D)  The  general  constitution  of  the  brain. — In  the  first  edition  (pp.  404,  409,  410, 
413),  in  accordance  with  the  commonly  accepted  view  based  upon  the  more  obvious  condi- 
tion of  the  parts  in  the  adults  of  the  higher  vertebrates,  the  entire  brain  was  regarded 
as  comprising  two  principal  regions,  a  caudal,  unpaired  and  a  cephalic,  paired.  After 
careful  reconsideration  of  the  matter,  especially  upon  the  embryological  and  other 
grounds  presented  by  the  senior  author  (5C»,  145-146),  we  are  led  to  regard  the  brain  as 
consisting  essentially  of  a  single  series  of  segments  and  cacities^  although  some  of  them 
may  present  lateral  protrusions,  so  that  the  original,  simple  cavity  becomes  triple,  with 
one  mesal,  and  two  lateral  portions. 

Leaving  out  of  view  the  suggestion  that  the  embryonic  optic  vesicles  may  represent 
the  lateral  divisions  of  the  diencephal,  and  that  the  "lateral  recesses  of  the  fourth  ven- 
tricle "  may  have  a  like  relation  to  the  metacoele  or  the  epicoele,  the  mesoccele  of  birds 
and  frogs  presents  a  distinctly  triple  constitution  (Wilder,  63 ,  328,  Fig.  4r-6),  with  a  mesal 
iter  and  lateral  optocoeles  connected  therewith  by  pylas,  comparable  with  the  division  of 
the  prosoccelian  cavity  into  the  mesal  aula  and  the  lateral  procoeles  connected  therewith 
by  the  portas.     This  serial  homology  is  indicated  in  the  following  table  : 


ENCEPHALOMERE. 

Prosencephal. 

Mesencephal. 

ENTIRE   CAVITY. 

Prosocoele. 

MesoccBle. 

MESAL   CAVITY. 

Aula. 

Iter. 

ORIFK^ES. 

Portas. 

Pylas. 

LATERAL  CAVITIES. 

ProccEles. 

Optocoeles. 

As  a  corollary  to  the  above  interpretation  of  each  encephalomere  as  essentially  mesal, 
with  or  without  lateral  portions,  it  follows  that  the  olfactory  lobes  are  no  longer  recognized 
by  us  as  constituting  a  second,  paired  segment  under  the  name  rliinencephal,  although 
their  cavities  may  still  be  conveniently  called  rhinocceles.  Hence  there  are  admitted  only 
five,  definitive,  encephalic  segments  instead  of  six,  as  in  the  first  edition. 

The  cerebellum  and  oblongata  are  regarded  by  Spitzka  {Id)  as  constituting  a,  single 
encephalomere,  while,  on  the  other  hand,  as  stated  more  fully  by  Wilder  {58),  there  are 
reasons  for  thinking  that  several  potential  segments  are  more  or  less  completely  repre- 
sented in  this  region.  Pending  the  more  complete  determination  of  the  number  of  these 
segments,  we  believe  the  ordinary  view  is  the  most  convenient  and  practical  one ;  that 
betvp^een  the  myel  and  the  optic  lobes  there  are  two  encephalomeres,  the  metencephal,  com- 
prising the  postoUongata,  and  the  epencephal,  including  the  cerebellum,  the  pons  and  the 
preoblongata.  But  when  it  is  needless  or  difficult  to  discriminate  between  them,  the 
entire  region,  as  suggested  by  the  senior  author  (6*5,  32)  may  be  denominated  metepencephal 
and  its  cavity  metepicode. 

(E)  If  the  names  of  the  principal,  neural  parts  on  the  following  Table  are  compared 
with  their  common  synonyms  it  will  be  seen  that  (i)  most  of  them  are  correlated  with 
other  names  of  parts  in  the  same  segment  of  the  brain  or  having  the  same  structure,  and 
(?)  all  of  them  are  mononyms,  consisting  of  a  single  word  each.  If  they  are  compared 
with  the  corresponding  terms  in  §  1058,  it  will  be  seen  that  in  place  of  the  Latin  aspect, 
most  of  them  are,  though  Latin  in  general  form,  English  in  termination  ;  they  are 
paronyms  of  the  Latin  names  ;  mesoccdia,  for  example,  is  mesocodey  myelon  and  encephalon 
become  myel  and  encephal,  etc.     See  preface  to  this  edition. 


400^ 


ANATOMICAL   TECHNOLOGY, 


TABULAR  ARRANGEMENT    OF    THE    NAMES  OF  THE  NEUROMERES  AND 

THEIR  CAVITIES. 

PROSENCEPHAL  ; 

secondary  forebrain  ; 

cerebrum,  olfactory  lobes. 

PROSOCflELE ; 

prosencephalic  cavity,  including  aula, 
portos,  prcxjo-'leSj  aod  rhinocoeks, 

DIENCEPHAL; 
'tween-brain  1 
thalami,  etc, 

DIACCELE; 

third  yentricle,  in  part. 


NEURON,' 

brain  and  cord  \ 

cerebro-spinal  axis ; 

myelencepliaL 

NEUROCCELE; 

myeleiicephalic  cavity ; 
central  canal  and  ven- 
tricles. 


ENCEPHAL  ; 
brain. 

ENCEPHALOC(ELE ; 

brain  cavities  \ 

ventricles. 


MESENCEPHAL ; 

mid-brain ; 

optic  lobes,  etc. 

MESOCCELE ; 

mesencephalic  cavity,  including  iter 

pylas,  and  optocceks. 


I" 
I" 

1  n  o 

eg 


MYEL; 

spinal  cord, 

MYELOCCELE, 
central  canal. 


EPENCEPHAL ; 

hind-brain ; 

cerebellmn  and  preoi)longata. 

EPICCELE ; 

fourth  ventricle,  in  fjan,  and 

cerebellar  ventricle. 


METENCEPHAL ; 

after-brain ; 
postoblongata,  etc. 

METAC(ELE ; 
fourth  ventricle,  in  part. 


.  LONGER  PORTION; 
myel  proper. 

SYRINGOC(ELE  ; 
central  canal  proper. 

INTTJMESCENTIA  LTJMBARIS; 
lumbar  enlargement. 

RHOMBOC(ELE  ; 
rhomboid  einus. 


With  unessential  modification,  the  above  table  is  a  reproduction 
of  one  published  by  the  senior  author  (^3,  356  ;)  compare  Fig.  110, 
and  Its  explanation  on  p.  410. 

The  names  of  the  neural  masses  are  in  heavy-faced  type  ;  those 
of  their  cavities  in  common  type.  Under  each  name  are  given 
one  or  more  of  the  synonyms  commonly  met  with. 


METHODS    OF    STUDYING    THE    BRAIX.  401 

able  functions.     Finally,  tlie  human  brain  is  usually  presented,  or 
at  least  employed  as  a  standard  for  comparison. 

From  personal  experience  and  from  the  uniform  testimony  of 
our  students,  we  have  been  led  to  the  following  conclusions :  — 

(A)  The  arrangements  of  the  solid  parts  of  the  brain  are  more 
readily  perceived  and  more  easily  remembered  after  the  relations 
of  the  cavities  are  fully  understood. 

(B)  An  adequate  idea  of  the  circumscription  of  the  cavities  in- 
volves a  distinct  recognition  of  their  lining  and  of  the  investment  of 
the  whole  brain. 

(C)  The  general  plan  of  the  organ  is  most  readily  appreciated  if 
we  disregard  altogether  its  organic  composition  and  its  direct  sub- 
servience to  mental  operations,  and  view  it  primarily  as  we  might 
any  artificial  structure,  like  a  house  or  a  piece  of  furniture  of  homo- 
geneous material. 

(D)  Even  if,  as  is  commonly  the  case,  the  human  brain  is  the 
ultimate  object  of  inquuy,  the  brain  of  some  Amphibian  should  be 
examined  first. 

§  1052.  So  far  as  we  know,  the  first  three  of  these  propositions  have  not  been  distinctly 
enunciated  heretofore. 

The  advantage  of  studying  first  the  cavities  of  the  brain  seems  to  arise  from  the  fact 
that  while  the  walls  are  subject  to  great  modifications  as  to  form,  thickness,  histological 
composition  and  connections,  the  cavities  can  present  differences  of  only  size,  shape  and 
degree  of  circumscription  ;  their  connections  are  invariable,  and  of  course  no  structure  is 
predicable  of  them.  Hence  fewer  considerations  are  presented  to  the  mind,  a  matter  of  no 
small  importance  to  the  beginner. 

§  1053.  To  the  physiologist  the  membranous  envelopes  are  of  interest  only  as  con- 
cerned in  the  vascular  supply  of  the  proper  nervous  tissue,  and  for  most  anatomical 
purposes  they  are  better  removed.  With  them,  however,  are  apt  to  come  away  some 
atrophied  parts  of  the  parietes  together  with  the  lining  of  the  cavities,  so  as  to  leave  the 
latter  open  at  certain  points.  Hence  many  figures  and  descriptions  indicate  or  imply  that 
there  are  free  communications  between  the  cavities  and  the  outside  of  the  brain. 

With  possibly  a  single  exception  (§  1082),  this  is  not  the  case,  in  adults  at  least,  and 
indeed  the  existence  of  such  communications  would  be  out  of  keeping  with  what  is  known 
of  the  mode  of  development  of  the  organ.  Hence  any  clear  and  adequate  conception  of 
the  relations  of  the  cavities  involves  the  distinct  recognition  of  the  presence  of  the  mem- 
branes and  of  their  general  arrangement. 

§  1054.  As  to  the  third  proposition,  the  comparative  anatomist  and  the  systematic 
zoologist  especially  desire  the  identification  of  the  various  regions  of  the  brain,  and  the 
determination  of  suitable  names  and  terms  for  description.  Even  where  the  histology 
and  functions  of  the  organ  are  the  ultimate  objects  of  its  study,  the  student  must  first 
become  familiar  with  the  order  of  succession  of  the  parts,  their  constant  topographical 
relations  and  the  connections  of  their  cavities,  and  with  the  names  of  them  all. 

Now  this  may  be  done  not  only  as  well,  but  in  our  opinion  more  easily,  if  all  other 
26 


402  ANATOMICAL    TECHNOLOGY. 

features  are  for  tlie  time  ignored,  and  the  brain  is  viewed  simply  as  a  series  of  cavities  with 
parietes  of  varying  thickness,  more  or  less  distinctly  divisible  into  walls,  floor  and  roof. 

§  1055.  The  fourth  proposition  is  in  accordance  with  the  following  general  aphorism  : — 

"  In  all  departments  of  investigation,  it  is  right  to  commence  with  the  study  of  that 
which  is  common,  simple  and  regular,  and  thence  to  proceed  to  inquire  respecting  tliat 
which  is  [complex],  unusual  and  irregular,"— Bucknill  and  Tuke,  A. 

The  specific  idea  is  admirably  expressed  in  the  following  passage  from  a  paper  in 
which  it  is  practically  carried  out  :— 

"  With  man  and  the  other  mammals,  the  cerebrum  and  cerebellum  so  far  transcend 
all  the  other  organs  of  the  encephalon,  that  the  parts  which  in  a  morphological  point  of 
view  are  of  equal  value  have  been  frequently  overlooked,  as  forming  either  integral  parts 
or  primary  subdivisions. 

"  In  frogs  .  .  .  while  no  one  part  takes  an  excessive  development,  there  is  at  the  same 
time  no  one  of  the  fundamental  ones  either  wholly  deficient  or  so  far  reduced  as  to  deprive 
the  general  plan  of  any  of  its  more  important  features.  The  brain  is  so  far  reduced  in  the 
relative  proportion  of  its  different  parts,  and  so  far  stripped  of  the  *  accessory  organs  of  per- 
fection,' as  to  enable  the  student  to  obtain  with  ease  a  clear  conception  of  the  general  plan, 
a  conception  always  so  diflBcult  to  acquire  when  studying  the  brain  of  mammals  or  of 
man." — Wyman,  34,  6. 

§  1056.  The  advantages  presented  by  the  frog's  brain  may  be  categorically  stated  as 
follows : — 

(1)  The  various  parts,  while  far  from  equal  in  size,  differ  much  less  than  in  the  higher 
Vertebrates. 

(2)  No  part  is  completely  hidden  by  another. 

(3)  All  lie  in  the  same  plane,  the  organ  not  presenting  the  perplexing  "  cranial  flex- 
ure "  (Quain,  A,  II,  733)  of  most  of  the  higher  Vertebrates. 

(4)  The  cavities  are  relatively  large, 

(5)  The  parietes  vary  little  in  thickness, 

(6)  While  all  the  primary  components  of  the  brain  are  present,  there  are  but  few  spe- 
cial additions  or  modifications  to  distract  attention  from  the  general  plan. 

Yet  the  frog's  brain  is  by  no  means  an  ideally  perfect  type  of  the  vertebrate  brain,  or 
wholly  adapted  for  study,  for  the  following  reasons  : — 

(1)  It  is  undesirably  small.  Hence  the  student  should  select  for  this  purpose  the  very 
largest  individuals,  if  possible  of  the  bullfrog,  Raiia  CatesUana  {pipiens  of  some  writers). 

(2)  The  tissue  is  very  soft.  Hence  great  care  is  needed,  and  the  organ  should  usually 
be  hardened. 

(3)  The  cerebellum  is  disproportionally  small, 

(4)  The  cavity  of  the  optici  presents  a  projection  of  the  wall  which  renders  a  section  of 
the  region  somewhat  puzzling. 

(5)  The  passages  {portce  or  foramina  of  Monro)  between  the  mesal  and  the  lateral  cavi- 
ties are  undesirably  small. 

(6)  The  cephalic  divisions,  the  Ldbi  olfactorii,  which  are  separate  in  all  other  Verte- 
brates, are,  in  the  frog  and  toad  and  other  anourous  Amphibia,  not  only  in  contact  upon 
the  meson,  but  there  united  by  somewhat  firm  connective  tissue,  constituting  a  feature 
which  has  seriously  misled  some  anatomists,  including  even  Wyman  (34,  8,  9), 

(7)  The  plexuses  are  nearly  or  wholly  absent. 

In  respect  to  the  last  four  objections,  the  brain  of  Menohranchus  is  preferable  to  that 
of  the  frog.  But  the  animal  is  less  easily  obtained,  the  cerebellum  is  even  smaller,  and  the 
optici  are  so  slightly  differentiated  from  the  parts  caudad  and  cephalad  as  to  render  some- 
what difficult  the  recognition  of  their  limits. 


PRINCIPAL    PARTS    OF    THE    AMPHIBIAN   BRAIN.  403 

Nevertheless,  tlie  brain  of  Menobi'anchus  is  well  worthy  of  examination  upon  the  fol- 
lowing grounds; — 

(1)  The  slight  differentiation  of  the  regions  is  an  interesting  renunder  of  the  presumed 
condition  of  all  brains  at  an  early  stage  of  development. 

(2)  The  size  of  the  cavities  and  communications  and  the  thinness  of  the  parietes  permit 
the  effects  of  inflation  with  air  to  be  at  once  aj^parent. 

(3)  The  Lohi  olfactoHi  are  disconnected,  as  in  all  Vertebrates  excepting  the  Anura. 

(4)  The  aula  is  large  and  well  defined. 

§  1057.  The  method  of  viewing  the  general  constitution  of  the  brain  which  was  sug- 
gested by  Wyman  and  is  herein  adopted  may  be  called  the  comparative  anatomy  way.  There 
is  another,  the  emhryological  way,  which  is  theoretically  more  satisfactory  and  complete, 
but  practically  not  well  adapted  to  beginners.  It  would  be  well,  however,  for  the  some- 
what advanced  student  to  obtain  a  collection  of  foetal  pigs,  kittens,  etc.,  of  different  ages, 
and  carefully  expose  their  brains  so  as  to  observe  the  gradual  increase  of  the  hemispheres 
and  cerebellum,  the  formation  of  the  gyri  and  the  progressive  thickening  of  the  walls  in 
the  greater  part  of  their  extent. 

§  1058.  Partial  Vocabulary. — The  following  List  includes  only 
the  names  of  the  principal  parts  of  the  Amphibian  brain.  A  more 
complete  macroscopic  vocabulary  of  the  organ  will  be  given  later  in 
this  chapter. 

Names  of  the  Principal  Parts  of  the  Amphibian  Brain.,  with 
their  more  Common  Synonyms. — Aula — V^entricle  of  the  ''  unpaired 
cerebral  rudiment."  Aulatela— Atrophied  or  membranous  roof  of 
aula.  Auliplexus — Plexus  choroideus  aulse.  Cerebrum — Hemi- 
sphserse,  larger  portion  of  prosencephalon.  Cerebellum — Dorsal 
portion  of  epencephalon.  Chiasma — Commissura  optica,  chiasma 
nervorum  opticorum.  Conarium — Corpus  pineale,  pineal  gland, 
epiphysis.  Crus  cerebri— Floor  of  mesocoelia.  Diacoelia — Ventric- 
ulus  tertius.  Diencephalon — Deutencephalon,  thalamencephalon. 
Diaplexus — Plexus  choroideus  ventriculi  tertii.  Diatela — Atro- 
phied or  membranous  roof  of  third  ventricle.  Endyma — Ependy  ma, 
lining  of  the  coelifB.  Epicoelia — Ventriculus  cerebelli,  cephalic  part 
of  ventriculus  quartus.  Epencephalon — Hiiid  brain.  Hemisphaera 
— Hemicerebrum.  Hypophysis — Corpus  pituitarium.  Lobusolfac- 
torius — Lateral  half  of  rhinencephalon.  Mesencephalon — Lobi 
optici  and  crura.  Mesocoelia — Ventriculus  loborum  opticorum, 
aquseductus  Sylvii,  iter  a  tertio  ad  ventriculum  quartum.  Meta- 
ccBlia — Caudal  portion  of  ventriculus  quartus.  Metatela — Atro- 
phied or  membranous  roof  of  ventriculus  quartus.  Metencephalon 
— Medulla.  Myelon — Chorda  spinalis.  Opticus — Lobus  opticus. 
Pia— Pia  mater.  Porta — Foramen  Monroi.  Portiplexus — Plexus 
choroideus  foraminis  Monroi.  Postcommissura — Commissura  pos- 
terior.    Prsecommissura — Commissura  anterior.     Procoelia — Ven- 


404  ANATOMICAL    TECHNOLOGY. 

triculus  lateralis.  Proplexus— Plexus  ventriculi  lateralis.  Prosen- 
cephalon—Cerebrum,  hemispliserse.  Pseudo-commissura — Connec- 
tive tissue  between  lobi  olfactorii  in  Anura.  Rhinencephalon — Lobi 
olfactorii.  Rhinoooelia—Ventri cuius  olfactorius.  Terma— Lamina 
terminalis,  lamina  cinerea.  Tuber  cinereum.  Thalamus — Tiiala- 
mus  nervi  optici,  wall  of  diacoelia.    Valvula — Valve  of  Vieussens. 

§  1059.  List  of  some  of  the  Technical  Names  of  the  Parts  most  frequently  mentioned, 
with  the  terms  {in  black  letter)  which  are  Preferred  to  them. — Aquaeductus  Sylvii — Meso- 
coelia.  Chorda  spinalis— Myelon.  Commi^sura  anterior — Praecommissura.  Commis- 
sura  posterior — Postcommissura.  Corpus  pineale — Conarium.  Corpus  pituitarium — 
Hypophysis.  Ependyma — Endyma.  Foramen  Monroi — Porta.  Iter  a  tertio  ad  ven- 
triculum  quartam — MesoccElia.  Lamina  terminalis  s.  cinerea — Terma.  Lobus  opticus 
— Opticus.  Medulla  oblongata— Metencephalon.  Pedunculus  cerebri — Crus  cerebri. 
Plexus  choroideus  ventriculi  tertii — Diaplexus.  Plexus  choroideus  ventriculi  lateralis — 
Proplexus.  Ventriculus  lateralis — Procoelia.  Ventricle  of  the  "  unpaired  cerebral  rudi- 
ment," mesal  part  of  ventriculus  lobi  communis — Aula.  Ventriculus  quartus — Meta- 
coelia.     Ventriculus  tertius — Diaccelia. 

Comparatice  Brevity  of  the  Terms  here  adopted. — In  the  above  list  there  are  19  new  names 
composed  of  20  words  and  about  150  letters.  The  corresponding  old  names  comprise  40 
words  and  about  300  letters.  Since  the  parts  specified  are  very  frequently  mentioned  in 
treating  of  the  macroscopic  anatomy  of  the  brain,  it  is  evident  that  a  substantial  saving  is 
effected  by  the  employmant  of  the  shorter  terms. 

§  1060.  Tfie  EiicepTiaUc  Segments. — All  brains  present  more  or 
less  marked  constrictions  with  intervening  enlargements  ;  the  caudal 
region  also  is  single  or  mesal,  while  tlie  cephalic  is  double  or  in  two 
lateral  parts.  Hence  the  brain  may  also  be  defined  as  an  incom- 
pletely segmented  tube  of  nervous  tissue^  bifurcated  at  one  end. 

In  each  of  these  segments  there  is  one  organ  or  pair  of  organs 
constituting  its  principal  or  characteristic  portion,  but  there  are 
always  some  other  parts  of  greater  or  less  importance. 

§  1061.  Names  of  the  Encephalic  Segments. — That  region  of  the 
brain  which  includes  the  {lobi)  optici,  which  is  easily  recognized  in 
most  adults  and  is  very  prominent  in  the  embryo,  has  been  almost 
uniformly  designated  by  the  technical  term  mesencephalon,  or  by 
its  vernacular  equivalents  mittelhirn  or  midbrain. 

With  regard  to  all  the  other  segments,  however,  there  has  been 
such  diversity  of  usage  that  the  student  is  apt  to  be  confused  in 
comparing  the  statements  of  different  writers.  In  the  following 
Table  are  given  the  principal  synonyms  of  the  names  ox  the  ence- 
phalic segments  herein  adopted,  which,  as  may  be  seen  by  compar- 
ing the  first  and  fifth  columns,  are  almost  identical  with  those 
which  are  given  in  the  Human  Anatomy  of  Quain  (A). 


ENCEPHALIC    SEGMENTS. 


405 


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40G  ANATOMICAL    TECHNOLOOY. 

§  1062.  Unequal  MorpJikal  Value  of  the  Segments.— ^o  far  as  appears  in  tlie  second 
column  of  the  Table,  the  six  segments  are  equal  primary  divisions. 

In  one  sense  this  is  certainly  not  the  case.  According  to  most  accounts  (Reichert,  A, 
II,  11  ;  Mihalkovics,  A,  21 ;  Spitzka,  (>,  27 ;  Huxley,  A,  50 ;  Quain,  A,  II,  750),  the 
embryonic  brain  consists  of  three  primary  vesicles ;  of  these  the  middle  is  developed  into 
the  me:iencephalon^  while  each  of  the  others  is  again  divided  into  secondary  vesicles,  from 
which  the  other  five  regions  are  formed.  Balfour,  however  (A,  II,  345),  admits  only  two 
primary  vesicles. 

Aside  from  the  verbal  distinctions  indicated  in  the  Table,  most  of  the  differences  are 
due  to  the  unequal  estimates  placed  by  writers  upon  the  several  segments  from  an  embryo- 
logical  point  of  view. 

Anatomically,  there  seems  to  be  no  objection  to  the  arrangement  here  adopted,  for 
while  the  cerebellum  and  hemispheres  preponderate  in  the  higher  animals,  the  optic  lobes 
are  larger  in  some  "  fishes,"  the  olfactory  lobes  are  enormous  in  some  sharks  and  placed 
at  a  considerable  distance  from  the  prosencephalon,  and  in  a  skate  {Torpedo)  the  largest 
part  of  the  brain  is  the  medulla. 

For  practical  purposes,  then,  the  six  segments  may  be  regarded  as  coordinate  divisions. 

§  1083.  Advantages  of  Using  the  Segmental  Names.— T\\qtq  are  three  advantages  in 
the  use  of  terms  designating  the  encephalic  segments : — 

(1)  They  indicate  the  segmental  constitution  of  the  brain. 

(2)  Each  designates  a  general  region  which  may  consist  of  several  more  or  less  distinct 
parts.  Mesencephalon,  for  example,  includes  not  only  the  optic  lobes,  but  the  crura 
cerebri,  etc. 

(3)  They  are  single  words  capable  of  inflection, 

§  1064.  Names  of  the  Cavities. — On  account  of  the  peculiar  condition  of  things  in  man 
and  the  higher  Mammals,  certain  portions  of  the  general  cavity  have  been  recognized  as 
such,  while  others  have  been  c^WeA  passages  or  ignored  altogether.  In  modern  times  the 
larger  cavities  have  been  usually  called  ventricles,  from  the  Latin  ventriculus. 

The  incongruity  of  the  anthropotomical  designations  of  the  encephalic  cavities  has 
been  pointed  out  by  Owen  (A,  I,  294,  note),  and  the  senior  author  (,9,  125,  14,  539). 

The  canalis  centralis  expands  into  a  cavity  which,  although  the  first  of  the  series,  is 
called  Xhe  fourth  ventricle.  The  more  or  less  distinct  cavities  corresponding  to  the  cere- 
helium  and  the  optici  are  not  called  ventricles  at  all,  and  the  second  is  known  by  either  of 
the  following  phrases  :  aqumductits  Sylcii  and  iter  a  tertio  ad  ventriculum  quartum.  The 
diencephalic  cavity  is  the  third  ventricle.  The  two  "  lateral  "  ventricles  are  rarely  men- 
tioned as  t\\Q  first  and  second,  but  since  the  numbers  must  be  understood  in  order  to  account 
for  the  third  aind  fourth,  the  student  desires,  in  vain,  to  know  which  is  the  first  and  which 
the  second.  In  point  of  fact,  if  the  enumeration  is  begun  at  the  cephalic  end  of  the  series, 
the  lateral  ventricles  are  the  third  and  fourth,  since,  in  most  air-breathing  Vertebrates, 
there  are  well-developed  ventricles  in  the  Lobi  o^factorii.  Finally,  a  " fftJi  ventricle  "  is 
mentioned,  which  is  not  only  at  a  great  distance  from  the  fourth,  but  has  no  normal  con- 
nection with  the  other  ventricles,  and  is,  in  fact,  no  part  of  the  series. 

It  is  hardly  possible  to  imagine  less  appropriate  and  consistent  appellations  for  a  series 
of  essentially  similar  cavities. 

Ventriculus  is  objectionable  because  of  its  length,  because  its  use  is  apparently  estab- 
lished in  connection  with  the  cardiac  cavities,  and  because,  as  a  Latin  word,  it  is  not  readily 
combined  with  Greek  prefixes.  No  one  of  these  objections  is  fatal,  but  combined  they  may 
be  regarded  as  warranting  the  use  of  another  word  if  such  can  be  found. 


NAMES    OF    THE    ENCEPHALIC    CAVITIES.  407 

The  Greeks  designated  eitlier  a  cardiac  or  an  enceplialic  cavity  by  the  name  KoOua,  and 
the  senior  author  has  proposed  (.9, 125,  14:,  540)  to  substitute  it  for  tentriculus,  and  to  des- 
ignate the  several  encephalic  cavities  by  terms  formed  by  its  combination  with  the  charac- 
teristic prefixes  of  the  encephalic  segments.  Tliis  gives  us  rhinocodia,  proccelia,  diaccelia. 
niesocmlia,  epiccelia  and  meiacoelia.  These  terms  aie  capable  of  inflection,  and  the  longest 
of  them  is  no  longer  than  the  Latin  mntriculus,  which  requires  a  prefix  or  qualifying 
word.  Finally,  when  the  student  has  once  learned  the  order  and  significance  of  the  names 
of  the  encephalic  segments,  he  has  only  to  acquire  a  single  term  and  apply  thereto  the  char- 
acteristic prefixes  with  which  he  is  already  familiar. 

%  1065.  Aula  and  Porta. — These  names  were  proposed  by  the  senior  author  (5,  0, 14^ 
540)  upon  the  following  grounds  : — 

(1)  To  substitute  brief  single  words  for  the  phrases:  " ventriculus  communis,"  "  ven- 
triculus  lobi  communis,"  cavity  of  the  "cerebral  rudiment/'  unpaired  hemisphere  vesicle 
or  "secondary  forebrain,"  mesal  part  of  the  "common  ventricular  cavity,"  foramen 
Monroi,  etc. 

(2)  Because  the  phrase  most  commonly  eni\>\oyed,  foramen  Monroi,  is  used  to  designate 
at  least  three  different  cavities  or  orifices :  (A)  The  cavity  by  which  either  proccelia  com- 
municates with  the  mesal  series  of  ccelise ;  (B)  the  two  lateral  orifices  tog-ether  with  the 
intervening  space  ;  (C)  the  mesal  (cephalic)  orifice  of  the  diacoelia.  We  have  been  unable 
to  ascertain  by  whom  the  phrase  was  first  employed,  and  the  description  by  Monro  secun- 
dus  (A,  12-16),  in  whose  honor  it  was  applied,  is  somewhat  vague  (Wilder,  3). 

(3)  In  order  to  indicate  our  opinion  of  the  desirability  of  recognizing  the  aula  as  mor- 
phologically an  important  element  of  the  ccelian  series. 

§  1066.  TelcB  and  Plexuses. — The  atrophied  or  membranous  roofs  of  certain  ccelise  are 
called  tela  vasculosa  or  ti^la  choroidea,  superior,  inferior,  etc.,  and  the  vascular  plexuses 
formed  by  them  are  designated  as  plexus  choroideus  ventriculi  tertii,  etc.  If  once  the 
general  names  for  the  encephalic  segments  and  ccelise  are  adopted,  we  have  only  to  employ 
the  characteristic  prefixes  and  gain  the  single  and  definite  names  metatela,  diatela,  aula- 
tela,  mctaplexus,  dioplexus,  auliplexus,  portiplexus  and  proplexus. 

§  1037.  Commissurce. — Of  the  bands  of  fibers,  or  aggregations  of  cells  and  fibers,  by 
which  the  parts  of  the  brain — especially  corresponding  parts  upon  the  two  sides — are  con- 
nected, some  are  called  commissures,  while  others  have  received  special  names.  These 
latter — callosam,  fornix,  pons  and  chiasma — are  retained,  but  the  other  three — as  proposed 
by  the  senior  author  (.9,  123,  14,  538) — are  here  simplified  by  prefixing  to  the  word  cmn- 
missura  the  syllables  prce,  post  and  medi. 

§  1068.  Tabular  Vieio  of  the  Encephalic  Segments  and  their  parts  in  the  Amphibian 
Brain. — The  accompanying  Table  contains  the  names  of  the  principal  parts  of  the  brains 
of  the  frog  and  Menobranclius  arranged  according  to  the  segments  which  they  constitute 
(Fig.  110-112).  Attention  is  called  to  the  recurrence  of  the  prefixes  characterizing  the  seg- 
ments in  the  names  of  the  corresponding  ccelice,  telce  and  plexuses  (§  1066).  A  somewhat 
similar  table  is  given  by  Mihalkovics  (A,  48),  including  also  the  names  of  the  parts  of  th«^ 
mammalian  brain  ;  see  also  Quain  (A,  II,  755). 

The  abbreviation  az.  indicates  that  the  part  is  azygous  or  unpaired  ;  the  rest  are  lateral 
and  paired. 


408 


AliA  TOMICAL     TECHNOL  OGY. 


Fig.  110-112. — Schematic  Diagrams  op  a  Simple  Brain. 


AN  IDEAL    SIMPLE  BRAIN, 


409 


§  1069.     TABULAR   ARRANGEMENT   OF   THE   PRINCIPAL  PARTS   OF    THE 

AMPHIBIAN    BRAIN, 


Segments. 


Prosencephal , 

DiencephaL  . . 

Mesencephal.. 
Epencephal., . 

Metencephal.. 


Cavities. 


Pariete?. 


Commisfeiures  and  Flexes. 


(  Prosoccele,  az.,   C  Hemicerebrum Precommissure,  az 

J  including   aula,  )  Olfactory  lobe Prosoplex,  az. 

I  az.,    porta    andjl  Terma,  az.,  end  and  floor. 
Vprocoele.  I  Aulatele,  as.,  roof. 


Diacoele,  az. 


TMesocoele,  az., 
J  including  iter, 
I  az.,  pyla  and 
Voptoccele 

EpiccEle,  az 


Metaccele,  as. . 


Thalamus,  side 

Tuber  cinereura,  az.,  floor. . 

Hypophysis,  az 

Diatele,  az.,  roof 

Conarium,  az. 

Optic  lobe,  roof  and  side. 
j  I  Crus,  floor. 

j  (  Cerebellum,  az.,  roof. 
J  Valvule,  az.,  roof. 

I  Preoblongata,  as.,  floor  and 

V     sides. 


{Postoblongata,  az  ,  floor  and! 
sides iMetaplex,  az. 
Metatele,  az.,  roof.  j 


Postcommissure,  az. 
Supracommissure,  az. 
Chiasm,  az. 
Diaplex. 


§  1070.  An  Ideal  Simple  Brain. — In  accordance  with  the  gen- 
eral plan  of  this  work  and  the  propositions  given  above  (§  1051), 
the  examination  of  the  actual  brains  of  the  frog  and  cat  may  be 
advantageously  prefaced  by  the  careful  study  of  the  preceding  dia- 
grams (Fig.  110-112),  which  present  to  the  eye  certain  essential  and 
fundamental  facts. 

Fig.  110-112.  Schematic  Diagrams  of  an  Ideal  Simple  Brain. — Fig.  110 — Longi- 
tudinal dextro-sinistral  section,  showing  the  relations  of  the  cavities,  the  sequence  of  the 
encephalic  segments  and  the  relations  of  the  coeliae. 

Fig.  Ill — Mesal  aspect  of  the  right  half  after  hemisection,  showing  the  contour  and 
constitution  of  the  coelian  floors  and  roofs. 

Fig.  112 — Transection  of  several  segments,  showing  the  ccelian  parietes. 

§^  1071.  Comments  upon  the  Diagrams  of  the  Brain. — Aside  from  the  prominence  given 
to  the  aula,  these  diagrams,  so  far  as  they  are  correct,  convey  no  information  or  ideas  not 
already  the  common  property  of  neurologists ;  they  are  intended  merely  as  msunl  aids  to 
the  student  in  the  someickat  onerous  task  of  learning  the  sequence  of  parts  and  associating 
the  names  therewith. 

They  do  not  accurately  represent  the  actual  condition  of  things  in  any  known  brain  at 
any  stage  of  development.  They  correspond  most  closely  with  tlie  brains  of  the  frog  and 
Menobranchus,  but  diflfer  from  the  former  in  the  disjunction  of  the  Ldbi  olfactorii,  from 


410  ANATOMICAL      TECHNOLOGY. 

tlie  latter  in  the  greater  difEerentiatioa  of  the  segments,  and  from  both  in  the  subglobular 
form  of  the  hemispheres. 

All  that  is  shown,  however,  might  really  exist  in  a  brain  without  contravention  of  our 
general  knowledge  of  the  structure  and  development  of  the  organ;  hence,  even  if  consid- 
erable modification  of  detail  should  be  required,  such  diagrams  would  still  be  useful  as 
an  elementary  introduction  to  the  study  of  the  brain. 

At  the  outset  the  student  will  do  well  to  regard  the  diagrams  as  purely  geometrical 
figures  or  as  representing  hollow  masses  of  wood  or  iron.  The  shading  is  conventional, 
and  intended  to  be  uniform  excepting  with  the  three  nerves  of  special  sense  in  Fig.  110. 
No  attempt  is  made  to  indicate  the  difference  between  the  true  nervous  parts  and  those 
{conarium  and  hypophysis)  which  may  consist  of  very  different  material,  between  the 
fibrous  and  cellular  portions  of  the  nervous  tissue,  or  between  the  longitudinal  and  trans- 
verse fibers  of  the  former. 

The  idea  of  diagrams  like  Pig.  110,  111  was  derived  from  the  very  clear  and  suggestive 
views  of  the  typical  brain  given  by  Huxley  (A,  Fig.  19,  20) ;  the  only  diagrams  known  to  us 
comparable  with  those  in  Fig.  112  were  published  by  the  senior  author  {22fV\.  Ill),  but 
the  membranes  were  not  included.  The  transections  of  the  frog's  brain  given  by  Siieda 
(Sii,  Taf.  XVIII)  are  of  actual  sections  and  likewise  omit  the  membranes. 

§  1072.  Fig,  110 — Horizontal  Section  of  the  entire  Neuron  (cerebro-spinal  axis). 
Copied,  with  slight  modification,  from  the  N.  Y.  Medical  Journal,  March  21,  1885.  p.  326, 
Fig.  2  (Wilder,  03).     Compare  the  Table  of  Names  on  page  400c?. 

Neurocmle  includes  the  entire  cavity  of  the  neuron  ;  the  caudal,  longer  and  narrower 
portion,  the  cavity  of  the  myel  or  spinal  cord,  is  called  myeloccde,  comprising  the  tubular 
syringocode  (central  canal)  and  the  more  or  less  expanded  rhomhoccele  of  the  "lumbar 
enlargement  ;"  the  rhomboccele  is  not  constant  in  adult  vertebrates  and  may  not  always 
appear  in  embryos,  but  its  existence  in  certain  mammalian  embryos  (dog,  Quain,  9th 
ed.,  II,  Fig.  648),  and  its  persistence  in  Birds  (Owen,  II,  117),  seem  to  warrant  its  inclusion 
in  the  jj resent  scheme. 

The  encephalocode,  or  general  brain  cavity,  is  here  regarded  as  including  five  divisions 
corresponding  with  the  five,  commonly  accepted,  encephalic  segments  or  encephalomeres  ; 
the  difficulties  and  questions  respecting  the  determination  of  the  number  and  limits  of 
the  encephalomeres,  and  their  designation,  have  been  set  forth  by  the  senior  author  («lJ»«S', 
03,  327). 

Three  of  the  encephalocoelcs  are  represented  as  simple,  although  it  is  by  no  means 
certain  that  both  the  epicoele  and  metacoele  do  not  present  lateral  protrusions,  and  the 
optic  vesicles  may  bear  that  relation  to  the  diacoele,  as  suggested  by  the  senior  author 
(»'>6*,  146).  The  mesocoele  of  man  and  other  mammals  presents  but  slight  indications  of 
a  triple  constitution,  but  in  Birds  and  Frogs  the  lateral  divisions  are  very  distinct  (Wilder, 
03,  Fig.  4-0).  The  prosoccelian  lateral  protrusions  (procoeles)  are  shown  in  their  sim- 
plest condition,  and  without  the  greater  extension  cephalad  which  masks  their  true  rela- 
tions in  most  vertebrates.  The  cavity  of  the  olfactory  lobe  (rhinoccEle  rhc.)  is  made  subor- 
dinate to  the  procoele,  althougli  this  relation  is  reversed  in  lamprey-eels,  and  may  not  really 
hold  good  in  other  vertebrates.  The  width  of  the  terma  is  exaggerated  for  the  sake  of 
distinguishing  fully  the  aula  or  mesal  division  of  the  prosocosle,  and  in  accordance  with 
the  representations  of  Balfour  (II,  Fig.  257)  and  Kolliker  (Fig.  311,  312).  Even,  however, 
were  no  width  assigned  to  the  terma,  the  aula  would  merely  be  reduced  from  a  quadrangle 
to  a  triangle,  and  still  liave  an  appreciable  extent. 

§  1073.  Fig.  Ill — Mesal  aspect  of  the  right  half  of  an  ideal,  amphibian  brain,  exclu- 
sive of  the  cephalic  portion  of  the  hemisphere  and  the  olfactory  lobe.     Of  course,  only  the 


I 


EXPLANATION    OF   DIAGRAMS.  411 


mesal  ccelice  appear  in  this  figure,  but  the  extent  of  the  right  procoelia  is  indicated  at  the 
cephalic  end  of  the  right  heraisphaera. 

The  porta  is  represented  by  the  dark  spot. 

The  order  of  succession  of  the  coeliae  and  of  the  segments  is  seen  to  be  the  same  as 
in  Fig.  110. 

As  in  Fig.  110,  the  shorter  transverse  lines  are  intersegmental,  and  the  longer  ones 
(A-H)  persegmental.  In  most  cases  the  latter  correspond  closely  with  those  of  the 
pers3gmental  lines  in  Fig.  110,  but  the  line  H  is  placed  farther  caudad,  there  being,  in 
the  frog  and  Menobranchus,  no  considerable  difference  between  the  parts  of  the  hemi- 
spheres. 

The  several  coeliae  are  named  as  in  Fig.  110,  but  in  place  of  the  names  of  the  ence- 
phalic segments  are  given  the  names  of  t\\e\T  principal  parts  (§  1069). 

The  floor  of  the  mesocmliti  is  formed  by  the  parts  called  crura  cerebri  in  the  higher 
Vertebrates,  and  its  sides  and  roof  by  the  optici.  Between  the  optici  and  the  cerebellum 
proper,  and  perhaps  belonging  in  part  to  both  segments,  is  a  thin  and  incurved  portion  of 
the  roof,  the  valvula  (Vieussenii). 

The  roof  of  the  diaecelia  is  variously  constituted.  Its  caudal  portion  consists  of  ner- 
vous tissue,  which  in  the  frog,  according  to  Wyman  (34,  11),  presents  commissural 
fibers,  the  postcommissura  (Stieda,  22,  17;  Ecker,  B,  Abt.  II,  10).  The  cephalic  part 
consists  mostly  of  the  membranes,  but  presents  the  thickening  commonly  known  as  cona- 
rium  or  epiphysis  or  pineal  gland  (Wyman,  34,  11),  which,  however,  may  be  only  an 
indication  of  the  place  of  attachment  of  the  true  conarium  (g  1084).  The  depressed  floor 
presents  a  diverticulum,  the  infundibulum,  leading  to  the  hypophysis  or  pituitary  body. 
Ventrad  of  the  cephalic  portion  of  the  floor  is  a  transverse  band  of  fibers,  the  chiasma  of 
the  optic  nerves. 

The  aula  forms  the  last  or  most  cephalic  of  the  mesal  series  of  cavities.  Most  of  its 
floor  and  part  of  its  cephalic  boundary  is  formed  by  the  terma,  of  which  the  praecommis- 
sura  {jjrcs.)  is  really  a  thickening  and  differentiation. 

In  this  figure,  instead  of  the  unbroken  lateral  walls  of  the  coeliae,  there  are  seen  the 
roofs  and  floors  of  the  me:al  series,  irregular  in  contour  and  variously  constituted  in  dif- 
ferent parts.  The  proper  nervous  tissue  is  atrophied  in  several  places,  and  the  coelian 
parieties  consist  chiefly  of  the  two  membranes,  the  enveloping  pia  and  the  lining  en- 
dyma  (§  1080). 

Each  of  these  membranes  is  represented  by  a  narrow  black  line,  while  in  this,  as  in 
Fig.  110,  the  surface  of  the  nervous  tissue  is  represented  by  a  heavy  line. 

The  metatela,  or  roof  of  the  metacoelia,  consists  chiefly  of  the  two  membranes.  The 
transverse  ridges  upon  its  ventral  aspect  in  the  frog  are  indicated  by  the  undulations  of 
the  ental  line.  The  roofs  of  the  aula  and  of  the  cephalic  part  of  the  diaecelia  are  also  mem- 
branous {aulatela  and  diatela).  In  the  frog  and  Menobranchus,  although  not  in  the  higher 
Vertebrates,  the  diacoelian  floor  is  devoid  of  nervous  tissue  along  the  meson,  but  no  special 
name  is  given  thereto. 

g  1074.    Fig.  112. — Transections  of  an  ideal  simple  brain  at  several  points. 

The  points  of  transaction  are  indicated  by  the  lines  connected  with  Fig.  110  and  by 
the  letters  A-H.  Of  course  the  continuity  of  the  coeliae  cannot  appear  in  these  sections, 
but  they  combine  the  distinctive  features  of  the  other  two  in  exhibiting  at  one  view  the 
I)eculiarities  of  the  sides  and  of  the  roof  and  floor. 

(A)  Transection  of  the  Myelon. — More  accurate  representations  are  given  of  this  in 
Fig.  99,  100,  109,  but  this  indicates  the  existence  of  the  canalis  centralis,  which  expands 
to  form  the  coeliae,  and  the  peculiar  form  of  the  deeply  fluted  column  of  cinerea,  which 


412  ANAT03fICAL     TECHNOLOGY. 

is  here  made  black  ;  tlie  shaded  portions  represent  the  lateral,  dorsal  and  ventral  columns 
of  alba. 

The  abbreviations  signify  as  follows  :—C^/;i.  d.,  Columna  dorsalis — "  posterior  white  " 
column.  Clm.l,  Columna  lateralis — "lateral  white"  column.  (Jim.  v.,  Columna  ven- 
tralis — "anterior  white"  column.  F.  dms.,  Fissura  dorsimesalis — "posterior"  fissure. 
F.  vms:,  Fissura  ventrimesalis — "anterior"  fissure.  Cm.  d.,  Cornu  dorsale  cinerese — 
"  posterior  horn  of  gray  matter."  Or7i.  v.,  Cornu  ventrale  cinereae — "  anterior  horn  of  gray 
matter." 

(B)  Metencephalon. — The  veutrimesal  fissure  is  nearly  obliterated,  but  the  sides  of 
the  dorsimesal  are  widely  separated,  and  the  central  canal  opened  into  connection  with 
the  space,  metaccelia,  so  formed.  The  roof  of  the  metacoelia  is  the  metatela,  composed 
of  the  pia  and  endyma,  and  the  mesal  ridge  is  indicated  by  the  undulation  of  the  latter. 

(C)  Epencephalon. — The  floor  and  sides  of  the  epicoelia  are  similar  to  those  of  the 
metacoelia  in  the  frog  and  Menobranchus,  but  in  Mammals  the  former  is  reinforced  by  the 
po)is,  and  the  latter  presents  three  sets  of  fibers,  the  pednnculi  of  the  cerebellum.  This 
latter  is  here  represented  in  its  essential  character  as  a  bridge  over  the  epiccelia  (Ecker,  B, 
Abt.  II,  8),  without  the  mesal  furrow  which  indicates  the  junction  of  the  optici  and 
thalami  of  the  two  sides, 

(D)  Mesencephalon. — Aside  from  its  greater  width,  the  chief  difference  between  this 
region  and  the  epencephalon  is  the  existence  of  the  distinct  dorsimesal  furrow,  whence 
the  name  corpus  bigemimim.  In  the  higher  Vertebrates,  the  floor  of  the  mesocojlia  is 
more  or  less  differentiated  as  the  crura  cerebri.  In  Menobranchus  the  mesocoelia  is 
large  and  simple  ;  in  most  Mammals  it  is  narrowed  by  the  approximately  uniform  thick- 
ening of  all  the  walls,  and  may  be  reduced  to  a  mere  passage.  In  the  frog  the  cavity  is 
very  irregular,  and  no  attempt  is  here  made  to  indicate  its  form,  excepting  on  the  left  of 
Fig.  110 ;  hence  the  difference  from  Fig.  16  and  17  of  Stieda  (22). 

(E)  Diencephalon.— This  transection  is  through  the  caudal  portion  of  the  segment. 
The  thalami  constitute  the  sides  of  the  diacoelia,  and  their  roof  presents  the  special  band 
of  fibers  known  as  the  postcommissura  (2?cs.).  At  the  ventrimeson  the  proper  nervous 
floor  is  absent,  but  the  two  membranes  are  unbroken.  The  slightly  protuberant  floor 
answers  to  the  more  distinct  tuber  cinereum  of  the  higher  Vertebrates ;  compare  Stieda 
(22,  Fig.  18).  In  the  right  of  the  diaccelia  is  represented  a  section  of  the  free  part  of 
the  right  diaplexus  of  Menobranchus  (§  1097),  which  does  not  exist  in  the  frog. 

(F)  Diencephalon. — This  is  through  the  cephalic  portion  of  the  segment.  The  two 
lateral  figures  represent  the  caudal  ends  of  the  hemisphcproe,  which  project  caudad  consid- 
erably beyond  their  points  of  attachment.  In  the  diencephalic  ])ortion  of  the  figure,  the 
sides  are'  the  thinner  cephalic  portions  of  the  thalami,  and  the  floor  is  reinforced  by  the 
chiasma ;  the  roof  is  membranous  at  the  sides,  but  thickened  at  the  meson  to  form  the 
conarium  or  its  continuation  (§  1084). 

(G)  Prosencephalon — Aula  and  Porta!. — The  two  proccEliae  are  seen  to  communicate 
with  a  mesal  cavity,  the  aula,  through  the  two  portae.  The  floor  of  the  aula  is  here 
formed  by  the  terma,  but  the  roof  {aulatela)  consists  of  only  the  membranes.  Compari' 
Stieda  (22,  Fig.  21),  where,  however,  the  membranes  are  omitted,  and  the  caudal  border 
of  the  prcECommissura  is  included,  so  as  to  separate  the  dorsal  part  of  the  aula  proper  from 
the  cephalo-ventral  portion. 

(H)  Prosencephalon — Hemisplicerce. — This  figure  may  represent  the  transection  of 
almost  any  portion  of  the  prosencephalon  or  rhineucephalon  cephalad  of  the  terma  ;  com- 
pare Stieda  (22,  Fig.  22).  The  hemispheres  are  usually  in  contact,  but  are  united  organ- 
ically only  in  Mammals  (by  the  callosum).     Their  cavities  {procceUce)  communicate  with 


RELATIONS    OF    THE    C(ELI^.  413 

oach  other  only  tlirougli  the  portm  and  aula.  In  addition  to  the  line  representing  the  'pia 
in  direct  contact  with  the  masses,  the  arachnoidea  {arch.)  is  represented  by  the  line 
bridging  the  interval  between  them. 

§  1075.  Relations  of  the  Cceliae. — These  are  most  clearly  indicated  in  Fig  110,  repre- 
senting a  horizontal  section  of  the  typical  brain.  The  cceliae  form  two  series,  caudal  and 
cephalic.  The  former  are  mesal  or  azygous,  the  latter  are  lateral  or  paired.  The  arrange- 
ment may  be  roughly  compared  to  a  two-tined  fork,  the  handle  representing  the  mesal 
series  and  the  prongs  the  two  lateral  extensions. 

A  more  accurate  analogy  is  with  the  apartments  of  a  house.  A  narrow  passage  (the 
canalis  centralis  of  the  myelon)  opens  into  a  wider  apartment,  or  rather  a  suite  of  apart- 
ments but  slightly  distinguished  from  each  other.  From  the  farther  (cephalic/  end  {aula)  a 
passage  {porta)  upon  either  side  opens  into  a  wing  or  lateral  extension,  each  containing 
two  apartments,  the  second  of  which  is  closed  at  the  farther  end. 

§  1076.  Comparison  of  the  Brain  with  a  House. — Let  us  imagine  that  a  house  con- 
sisting of  a  series  of  apartments  in  the  order  represented  in  Fig.  110  is  completely  envel- 
oped by  a  continuous  layer  of  tarred  jjaper,  and  that  its  rooms  are  lined  throughout 
with  wall  paper,  the  ceilings  and  floors  being  covered  with  the  same. 

Now  it  is  conceivable  that  (1)  the  proper  wooden  wall  of  any  apartment  might  be  so 
reduced  in  thickness  at  any  point  as  to  hardly  merit  the  name ;  (2)  it  might  be  omitted 
altogether  along  a  given  line,  leaving  only  the  two  layers  of  paper  ;  (3)  a  fold  of  the  ental 
or  lining  paper  might  hang  within  the  apartment ;  (4)  between  the  two  layers  of  the  fold 
might  be  interposed  a  fold  of  the  ectal  or  covering  paper  ;  (5)  instead  of  a  complete  fold 
of  the  ectal  paper  there  might  be  supported  in  the  fold  of  the  ental  some  looped  strings  or 
fringes  connected  primarily  with  the  ectal  layer. 

It  is  also  evident  that  (1)  while  the  fold  of  ental  paper  is  really  projected  into  the  apart- 
ment, (2)  the  fold  of  ectal  i)aper,  or  the  strings  or  fringes  of  that  paper,  are  covered  by  the 
ental  paper,  and  are  therefore  not  really  within  the  apartment  ;  (3)  any  force  applied  from 
within  or  without  will  be  likely  to  rupture  the  wall  along  the  line  of  interruption  of  the 
proper  Avooden  wall,  corresponding  with  the  line  of  reflection  of  the  ental  paper  therefrom 
to  form  the  fold. 

§  1077.  Arachnoidea. — After  the  removal  of  the  cranium  and  the  dura  which  lines  it, 
the  brain  of  the  frog,  cat,  man,  and  presumably  of  all  Vertebrates,  is  found  to  be  covered 
by  two  membranes.  Of  these,  the  ectal  is  the  more  delicate,  and  is  known  as  the  arach- 
noid. It  was  formerly  described  as  presenting  two  layers,  a  visceral  next  to  the  brain  and 
ii  parietal  lining  the  dura  ;  according  to  Quain  (A,  II,  573),  there  is  insufficient  evidence  of 
the  existence  of  the  latter,  and  it  is  not  represented  herein. 

The  arachnoid  passes  from  lobe  to  lobe  and  from  fold  to  fold  across  intervening  spaces 
or  fissures,  or  dips  but  slightly  therein. 

§  1078.  Pia. — This  is  in  direct  contact  with  the  brain,  follows  closely  the  contour  of 
the  lobes  and  folds,  is  pigmented  in  the  frog  and  some  other  animals,  and  supports  blood 
vessels  which  send  branches  into  the  substance  of  the  brain. 

The  pia  is  represented  in  all  parts  of  Fig.  Ill  and  112  ;  the  arachnoid  only  in  Fig. 
112,  H. 

§  1079.  Eiidyma.—M  intimated  by  Todd  (A,  634),  Duval  {2,  164),  Wyman  (34,  15). 
Balfour  (A,  II,  364),  and  Quain  (A,  IF,  510),  and  confirmed  by  our  observations,  all  parts 
of  the  true  cavities  of  the  vertebrate  brain  are  lined  by  a  smooth  epithelium  called  epen- 
dyma  or  endyma,  the  shorter  name  being  preferable.  This  is  akin  to  a  serous  mem- 
brane, and  secretes  a  watery  liquid  which  may  (as  in  hydrocephalus)  be  produced  in  lar^e 
amount. 


414  ANATOMICAL     TECHNOLOGY. 

§  1080.  Tel(P.~The,  pia  bears  to  the  brain  which  it  covers  the  relation  which  the 
tarred  paper  does  to  the  house,  while  the  paper  covering  the  interior  walls  is  represented 
in  the  brain  by  the  endyma. 

Where  the  proper  nervous  substance  of  the  coelian  parietes  is  atrophied  so  that  the  pia 
and  the  endyma  are  nearly  or  quite  in  contact,  the  resultant  is  called  a  tela. 

With  the  cat,  and  probably  with  other  animals,  the  telae  sometimes  seem  to  be  not 
altogether  devoid  of  nervous  structure  ;  indeed,  it  would  seem  quite  possible  that  between 
a  true  membranous  tela  and  a  thin  nervous  lamina  like  the  cephalic  part  of  the  talvula 
there  may  be  at  least  one  intermediate  condition. 

When  the  pia  is  removed,  the  telae,  being  connected  therewith,  are  apt  to  be  torn  off ; 
but  the  consequent  exposure  of  the  cnxities  is  no  more  proof  of  the  presence  <f  a  natural  ori- 
fice than  is  the  fontanelle  of  a  child,  after  the  remo'cal  of  the  scalp  and  the  dura,  evidence 
that  the  cranial  cacity  is  naturally  in  free  communication  with  the  outside  of  the  head. 

§  1081.  Plexuses. — Notwithstanding  the  more  or  less  elaborate  accounts  in  works  upon 
Descriptive  Anatomy,  and  some  recent  eiforts  to  elucidate  their  mode  of  development, 
the  precise  structure  and  arrangement  of  the  plexufjes  is  far  from  well  ascertained.  Indeed, 
it  is  probable  that  a  plexus  may  be  formed  in  two  or  more  ways  in  different  species  or  in 
different  parts  of  the  same  brain. 

As  we  understand  the  matter,  a  coelian  plexus  is  formed  in  one  of  two  ways  : — 

(A)  Certain  vessels  of  the  pia  are  protruded  entad  of  the  proper  nervous  parietes  so  as 
apparently  to  enter  the  coelise. 

(B)  Certain  parts  of  the  pia  containing  vessels  are  carried  as  folds  entad  of  the  parietes 
so  as  apparently  to  enter  the  coeliae  (Fig.  121). 

In  either  case  the  endyma  along  the  line  of  interruption  of  the  proper  nervous  wall  is 
reflected  upon  the  intruded  pia  or  vessels  and  covers  them  completely  ;  hence,  while  the 
thinness  of  the  epithelium  permits  osmosis  to  occur  practically  as  if  the  vessels  were  free, 
yet  from  a  morphological  point  of  view  they  are  not  free,  but  are  excluded  from  the  cavity 
just  as  the  kidney  or  the  intestine  is  excluded  from  the  abdomen  by  the  visceral  layer  of 
peritoneum  (Fig.  78)  ;  in  fact,  the  cases  are  strictly  comparable. 

§  1082.  The  alleged  "Foramen  of  Magendie."—Magendie  described  (A),  under  the 
name  "orifice  des  cavites  eucephaliques,"  an  opening  which  he  believed  to  exist  in  the 
metatela  near  the  caudal  end  of  the  metacoelia.  lAischka  figured  it  (A,  Taf.  Ill,  Fig.  1). 
but  no  other  representation  is  known  to  us,  although  its  existence  is  generally  admitted 
(as  in  Quain,  A,  II,  513  ;  Mihalkovics,  A,  59). 

Todd,  however  (A,  641),  believes  such  an  orifice  to  be  artificially  produced  ;  the  senior 
author  ( 14,  543,  555)  could  not  find  it  in  the  cat,  and  its  natural  presence  is  emphatically 
dsnied  by  Duval  {1,  33).     See,  however,  Westbrook  {1). 

§  1083.  Complete  Circumscription  of  tlie  Camties. — First  in  1876 
(Wilder,  4 ;  0, 136),  and  frequently  since,  we  have  made  upon  the 
cat's  brain  experiments  (by  inflation  with  air  and  by  the  injection 
of  alcohol,  water  and  plaster),  which  failed  to  indicate  the  presence 
of  any  natural  communication  (as  by  the  rima  or  "  fissure  of  Bi- 
chat"  or  "great  transverse  fissure")  between  the  coelise  and  the 
exterior. 

Upon  a  point  of  general  arrangement  like  this  there  is  every 
presumption  in  favor  of  uniformity  throughout  the  vertebrate  series ; 
hence  we  may  fairly  regard  the  coelicB  (excepting  at  an  early  stage 


CONARIUM    AND    HYPOPHYSIS.  4J"5 

of  development)  as  completely  circumscribed^  usually  by  nervous 
tissue,  always  by  membranes. 

This  idea  is  more  or  less  distinctly  enunciated,  upon  various  grounds  and  respecting 
various  animals,  by  tlie  following'  writers  :  Foster  and  Langley  (A,  224);  Balfour  (A,  364); 
Todd  (A,  634);  Mihalkovics  (A,  115);  Duval  {2,  33);  Quain  (A,  II,  546);  Hadlicli  (i); 
Lowe  (A)  :  Mivart  (B,  266) ;  and  probably  others. 

§  1084,  The  Conarlal  Tube. — The  above  statement  respecting  the  complete  circumscrip- 
tion of  the  coelise  excluded  the  earlier  embryonic  stages  on  account  of  the  views  of  Gotte 
(A).  According  to  this  observer,  as  briefly  stated  by  Balfour  (A,  856),  the  conarium  is  the 
remnant  of  the  canal  by  which,  as  is  commonly  believed  for  Vertebrates  in  general,  the  cavity 
of  the  embryo  myelencephalon  communicates  with  the  ectal  surface  of  the  head.  Accord- 
ing to  Stieda,  as  stated  by  Balfour  (A,  357),  a  part  of  the  conarial  tract  persists  upon  the 
outside  of  the  cranium  with  some  Amphibia,  and  the  corresponding  orifice  of  the  cranium 
Is  identified  as  the  parietal  foramen  of  some  fossil  Reptiles  by  Owen  {!).  The  entire 
*'  conario-hypophysial  tract,"  as  it  is  termed  by  Owen,  has  great  morphological  interest, 
but  for  our  present  purposes  it  seems  best  to  omit  any  detailed  account  of  the  various 
views,  and  to  refer  only  to  the  generally  accepted  opinion  as  to  the  primitive  origin  of  the 
hypophysis  from  the  alimentary  canal.  (Owen,  1  ;  Balfour.  A,  II,  3o8  ;  Quain,  A,  II,  735  ; 
Foster  and  Balfour,  A,  91  ;  Parker  and  Bettany,  A,  10 ;  Mihalkovics,  A,  83). 

STUDY  OF  THE  AMPHIBIAN  BRAIN. 

§  1085.  Obtaining  the  Animals. — Directions  for  prociiring  frogs 
and  Menobranchi  and  caring  for  them  will  be  given  in  the  Appen- 
dix. Large  examples  are  to  be  preferred  for  the  study  of  the  brain, 
and  they  should  be  obtained  alive  or  freshly  killed. 

§  1086.  Killing. — Place  the  animal  in  a  jar  or  covered  vessel  of 
water,  and  pour  off  any  water  in  excess  of  what  is  needed  to  simply 
submerge  it. 

Pour  in  a  little  chloroform,  not  more  than  5  cc.  ;  it  will  sink  to 
the  bottom  as  oily  looking  drops.  The  movements  of  the  animal 
will  usually  diffuse  it  more  or  less,  and  the  vessel  may  be  shaken  if 
necessary.     Death  will  ensue  in  10-30  minutes. 

If  etJier  is  used,  it  will  float  upon  the  top  of  the  water,  the  ves- 
sel must  be  shaken,  a  longer  time  is  required,  and  the  animal  is 
more  likely  to  revive  unless  the  subsequent  operations  are  done 
without  delay. 

If  no  anaesthetic  is  at  hand,  decapitation  may  be  performed  with 
the  bone  scissors  by  cutting  caudad  from  each  angle  of  the  mouth 
to  the  caudal  margin  of  the  brachium  in  the  frog  and  the  caudal 
gill  in  Menobranchus,  and  then  cutting  transversely  so  as  to  sepa- 
rate the  cranium  and  maxilla,  with  the  first  two  or  three  vertebrae, 
from  the  mandible  and  the  rest  of  the  body.     TTiis  should  be  first 


416  A  XA  T03IICA  L     TECffXOL  OGY, 

practiced  upon  dead  animals,  and  should  he  done  very  rapidly 
and  by  only  three  strokes  of  the  scissors. 

If  only  the  cephalic  portion  of  the  brain  is  wanted  for  some  special  purpose,  the  animal 
may  be  pithed  as  directed  in  the  Appendix  ;  the  brain  should  be  exposed  at  once  so  as  to 
prevent  the  clotting  of  blood  about  it. 

If  a  toad  is  used,  it  should  be  put  into  a  small  jar  or  under  an  "  open-top  "  bell  jar,  and 
a  sponge  saturated  with  chloroform  suspended  by  a  string  near  the  top.  In  handling  the 
toad,  it  is  well  to  protect  the  fingers  with  gloves  or  a  cloth,  and  care  should  be  taken  not 
to  get  the  acrid  dermal  secretion  into  the  eyes. 

§  1087.  Injection. — For  the  special  study  of  the  tel(JB  and  plexuses,  the  vessels  should 
be  injected.  Tliis  is  most  conveniently  done  with  cold  flowing  blue  material  from  the 
bulbus  arteriosus  ;  see  Appendix. 

§  1088.  Exposure  of  the  Frog's  Brain — Instruments  and  Ma- 
terials.— Small  tray  with  waste  paper ;  bit  of  cloth  ;  arthrotome ; 
coarse  forceps  ;  pointed  nippers  ;  bone  scissors,  not  too  dull ;  wide 
mouthed  vial  containing  at  least  25  cc.  of  62-67  per  cent,  alcohol ; 
(to  10  cc.  of  water  add  15  or  20  cc.  of  95  per  cent,  alcohol ;  see 
§  273) ;  refer  to  some  figure  of  the  bmin  (§  1093). 

Fix  the  head  by  introducing  the  tip  of  the  left  index  into  the 
mouth  and  applying  the  poUex  upon  the  snout.  With  the  scissors 
or  arthrotome,  divide  the  skin  between  the  cephalic  angles  of  the 
eyes. 

With  the  forceps,  grasp  the  caudal  cut  edge  of  skin,  and  with 
the  scissors,  cut  the  skin  along  a  line  extending  approximately  cau- 
dad  and  just  mesad  of  the  eye  and  the  ear  {membrana  tympani)  on 
each  side  as  far  as  a  point  opposite  the  caudal  border  of  the  bra- 
chium.  Connect  the  caudal  ends  of  the  two  incisions  so  as  to  removet 
the  flap. 

Grasp  the  left  dorsal  eyelid,  and  with  the  scissors  cut  mesad  of  1 
the  eyeball,  gradually  everting  it  and  cutting  the  muscles  until  the 
round,  white  iV.  opticus  is  divided.  Then  cut  more  boldly  and 
remove  the  entire  ball. 

From  the  orbit  push  a  scissors  blade  through  the  mucosa  intc. 
the  mouth,  and  cut  cephalad  through  the  snout.  Then  cut  caudad 
in  the  same  way,  along  the  same  line  or  a  little  farther  laterad,  ae 
far  as  the  skin  was  removed.  Finally,  cut  from  the  angle  of  tht 
mouth  so  as  to  remove  the  bony  projection  containing  the  left  tym 
panum  or  middle  ear. 

With  the  nippers,  tear  up  the  muscles  dorsad  and  laterad  of  th< 
caudal  part  of  the  cranium  and  the  first  two  or  three  vertebrae. 

Cautiously  nip  off  the  projecting  border  of  the  cranium  at  th 


EXPOSURE    OF    THE    BRAIN    OF   3IEN0BRANCHUS,  417 

orbit  until  the  left  Lohus  olfaciorins  or  the  hemisphere  is  exposed. 
Continue  to  remove  that  side  of  the  cranium  and  the  roof  in  very 
small  pieces  and  with  great  care.  The  widest  part  of  the  brain  {me- 
sencephalon^ optici)  lies  opposite  where  the  tympanum  was  removed, 
and  is  liable  to  injury  unless  the  adjoining  cartilaginous  capsule  of 
the  internal  ear  is  removed  very  cautiously. 

Caudad  of  the  mesencephalon  the  brain  is  narrower  and  merges 
into  the  myelon^  which  must  be  exposed  by  the  removal  of  the 
neural  arches  ;  it  will  be  necessary  to  cut  away  part  of  a  thin  car- 
tilaginous plate  upon  the  shoulder,  the  suprascapula  (§  383). 

Pass  a  scissors  blade  through  the  pharynx  to  the  dextral  angle 
of  the  mouth  and  cut  obliquely,  so  as  to  separate  the  cranium  and 
two  or  three  vertebrse  from  the  rest  of  the  body. 

§  1089.  Exposure  of  the  Brain  of  Menohranchus. — Instruments 
and  materials  (§  1088).  With  the  arthrotome,  cut  the  skin  upon  a 
transverse  line  just  cephalad  of  the  eyes.  With  the  scissors,  cut 
caudad  along  a  line  just  mesad  of  the  eye  on  each  side  to  a  point 
opposite  the  caudal  gill.  Raise  and  remove  the  flap  so  outlined, 
noting  that  the  skin  adheres  more  closely  than  in  the  frog,  and  that 
between  it  and  the  cranium  there  are  considerable  muscles. 

With  the  arthrotome  scrape  .the  muscles  from  the  bone,  begin- 
ning at  the  cephalic  end  of  the  exposed  area.  Alternately  ventri- 
duct  and  dorsiduct  the  head  so  as  to  indicate  the  position  of  the 
occipito-atlantal  arthron.  With  the  arthrotome,  carefully  pick  up 
the  membrane  between  the  atlantal  neural  arch  and  the  cranium  so 
as  to  expose  the  metencephalon  (medulla). 

With  the  nippers  remove  the  neural  arches  of  the  first  two  or 
three  vertebrae,  taking  care  not  to  wound  the  myelon.  Then  remove 
the  occiput  in  like  manner,  inserting  the  nipper  blade  but  a  very  little 
way.  The  larger  part  of  the  cranial  roof  is  very  thin  and  may  often 
be  lifted  in  slivers  upon  the  point  of  the  arthrotome,  but  with  large 
individuals  the  nippers  may  be  needed.  Special  pains  should  be 
taken  not  to  disturb  the  metatela^  a  pigmented  and  vascular  curtain 
just  cephalad  of  the  occiput,  which  sometimes  adheres  to  the  skull 
or  is  caught  by  the  point  of  the  instrument. 

When  the  dorsal  aspect  of  the  brain  is  exposed,  with  the  scissors 
cut  away  the  left  side  of  the  head  along  the  line  of  incision  of  the 
skin,  and  then  cut  across  the  vertebral  column  and  other  parts 
obliquely  from  the  caudal  end  of  the  incision  to  the  dextral  angle 
of  the  mouth. 
27 


418  AIVAT03nCAL     TECHNOLOGY. 

%  1090.  Preservation. — Place  the  preparation  in  the  62-67  per 
cent,  alcohol  for  at  least  two  days.  Then  transfer  it  to  95  per  cent, 
alcohol,  where  it  should  remain  if  a  permanent  preparation  is  to  be 
made.  For  most  purposes  it  is  best  to  leave  the  brain  supported  by 
part  of  the  cranium.  If  the  base  of  the  brain  is  to  be  specially 
studied,  the  base  of  the  skull  must  be  more  completely  removed ; 
it  is  thin,  but  so  closely  in  contact  with  the  brain  that  much  care  is 
required. 

§  1091.  Labeling, — To  the  vial  containing  the  brain  should  be  aflBxed  a  tag  (§  163) 
bearing  the  name  oi"  the  genus  and,  if  possible,  of  the  species,  and  stating  the  sex  and 
locality  of  the  animal,  the  date  of  the  preparation,  and  the  name  of  the  preparator. 

The  genus  will  be  either  Mendbranchus  (sometimes  called  Necturus),  Rana  (frog),  or 
Bvfo  (toad).  Probably  there  is  only  a  single  species  of  Menobranchus,  lateralis,  but  the 
doubt  upon  this  point  renders  the  noting  of  the  locality  essential.  Of  the  toad  there  is 
but  one  species,  lentiginosus  {Americana),  common  in  the  Northern  United  States.  There 
are  several  species  of  frogs,  the  largest  being  R.  pipiens  of  some  authors,  but  R.  Gatesbi- 
ana  accordino  to  Jordan's  '*  Manual  "  (A,  188). 

If  any  generalizations  are  to  be  based  upon  the  specific  characters  of  the  brain,  and 
there  is  doubt  respecting  the  determination,  the  entire  body  should  be  kept  for  reference, 
and  labeled  like  the  brain. 

With  the  female  Menobranchus  the  vent  is  a  simple  longitudinal  slit,  but  with  the 
male  it  presents  numerous  papillae,  especially  in  the  spring.  If  in  doubt,  open  the  abdo- 
men and  note  that  the  testes  are  elongated  solid  organs,  while  the  ovaries  are  thin  walled 
sacs,  one  on  each  side,  with  ova  of  two  or  more  sizes,  the  largest  in  the  spring  being  yel- 
low and  nearly  as  large  as  small  peas.  With  frogs  and  toads  the  testes  are  small  oval 
bodies,  while  the  ovaries  are  voluminous  laminae  with  dark  colored  eggs. 

§  1092.  General  Inspection  of  the  Amphibian  Brain. — In  what 
follows,  including  the  dissection  of  the  brain,  no  attempt  is  made  to 
give  exhaustive  descriptions  or  directions. 

Notwithstanding  the  numerous  figures  and  descriptions  of  the  frog's  brain,  none  of  its 
parts  are  known  as  they  should  be,  and  that  of  Menobranchus  can  hardly  be  said  to  be 
known  at  all  excepting  in  the  most  general  way.  But  our  ignorance  of  many  details  of 
their  anatomy  need  not  prevent  our  use  of  them  for  the  sake  of  illustrating  certain  features 
of  brain  construction  which  are  comparatively  obvious  with  them,  but  obscured  with  the 
brains  of  the  higher  Vertebrates. 

Since  the  frog  is  the  more  common  and  likely  to  be  used  more  frequently,  the  directions 
apply  primarily  to  it,  while  the  peculiarities  of  Menobranchus  are  separately  mentioned. 

§  1093.  Frogs'  brains  are  figured  and  more  or  less  fully  described  in  the  following 
works  and  papers.  So  far  as  we  can  judge,  the  figures  are  original  in  only  the  first  seven  : 
Wyman,  34  ;  Ecker,  B  ;  Gegenbaur  (Lankester),  A,  Fig.  283;  Leuret  et  Gratiolet,  A, 
PI.  II ;  Laurencet,  A,  PI.  II  ;  Spurzheim,  A,  PI.  Ill ;  Bourgery  and  Jacob,  A,  VIII,  PI.  22, 
Fig.  4 ;  Mivart,  A,  Fig.  74  ;  Huxley,  A,  Fig.  59  ;  Cyon.  A,  Taf.  24 ;  McAlpine,  A,  PI.  21 ; 
Burdon-Sanderson,  A,  PI.  109  ;  Packard,  A,  Fig.  373. 

Figures  of  the  brain  of  Mendbranchus  or  other  urodelous  Amphibia  are  given  in  the 
following ;  the  accompanying  descriptions  are  usually  very  meager :  Mayer,  A  ;  Laurencet, 


INSPECTION    OF    THE    AMPHIBIAN   BRAIN.  419 

A,  PI.  II  ;  Wyman,  34,  PI.  I  ;    Duges,  4,  PI.  10  ;  Bourgery  and  Jacob,  A,  VIII,  PI.  22, 
Fig.  7  ;  Owen  (Linnean  Transactions,  XVIII,  PI.  27). 

§  1094.  Instruments  and  Materials. — Tripod  magnifier;  line 
forceps  ;  beaded  bristles  ;  small  dish  of  62-67  per  cent,  alcohol  or  15 
per  cent,  glycerin  in  which  the  brain  may  be  dipped,  or  a  vial  of  the 
same  with  a  quill  duster  for  applying  the  liquid. 

Keep  the  brain  wet  with  the  alcohol  or  glycerin. 

Remove  the  w^hite  masses  of  calcareous  crystals  at  the  side  of 
the  caudal  region. 

Compare  the  several  regions  with  Fig.  110,  or  with  figures  in 
other  works  (§  1093). 

§  1095.  Note  the  lateral  expansion  of  the  myelon  to  form  the 
metencephalon  (medulla),  abrupt  in  the  frog,  very  gradual  in  Men- 
obranchus. 

Note  the  pigmented  metatela  which  forms  the  dorsal  surface  of 
the  metencephalon. 

If  the  metatela  is  in  place,  its  cephalic  border  more  or  less  com- 
pletely covers  the  cerebellum.  Grasp  its  sinistro-cephalic  angle 
with  the  forceps  and  invert  it  gently  until  it  lies  dextrad  of  the 
metencephalon.  Note  its  thickness  as  compared  with  the  my  clonal 
^m,  and  the  symmetrical  corrugation  of  the  ental  surface.  The 
cavity  thus  exposed  is  the  metaccelia  (ventriculus  quartus). 

In  Menobranclius  the  metaccelia  is  much  elongated,  and  the  caudal  part  of  the  meta- 
tela is  very  thin. 

Cautiously  remove  the  arachnoid  from  the  dorsal  aspect  of  the 
entire  brain,  excepting  just  between  the  divergent  caudal  ends  of 
the  hemispheres ;  it  is  little  if  at  all  pigmented,  and  bridges  the 
interhemispheral  fissure  as  shown  in  Fig.  112,  H. 

The  Avidest  region  is  the  mesencephalon  {optici\  the  pia  of 
which  is  thickly  pigmented.  Note  the  marked  mesal  furrow  be- 
tween the  two  lateral  convexities,  and  that  the  longer  axes  of  the 
latter  diverge  cephalad. 

In  Menobranchus  the  mesencephalon  is  but  little  wider  than  the  adjoining  segments, 
the  mesal  furrow  is  very  shallow,  and  the  lateral  masses  hardly  merit  the  name  of  lobes. 

Between  the  optici  and  the  metaccelia  is  a  narrow  transverse 
band,  unpigmented  and  with  its  caudal  margin  dorsiverted,  and 
separated  from  the  optici  by  a  somewhat  deep  furrow.  This  is  the 
cerebellum,  the  dorsal  part  of  the  epencephalon. 


420  ANATOMICAL    TECHNOLOGY. 

In  Menobranchus  the  cerebellum  is  very  narrow,  its  caudal  margin  is  not  dorsiverted, 
there  is  no  furrow  between  it  and  the  optici,  and  it  is  distinguishable  from  them  mainly 
by  the  absence  of  pigment. 

The  diencephalon  is  decidedly  narrower  than  the  parts  cepha- 
lad  and  caudad  of  it  and  is  partly  covered  by  their  projections,  and 
the  mesal  furrow  is  less  deep  than  between  the  optici.  In  Meno- 
branchus its  caudal  limit  is  not  easy  to  assign. 

Upon  the  cephalic  part  of  the  diencephalon  rests  the  conarium 
(or  its  continuation,  §  1084) ;  this  body  is  not  round,  as  almost  uni- 
versally shown,  but  oval,  and  anienerted  so  as  to  rest  also  upon  the 
roof  of  the  aula.     See  p.  4i)0a. 

If  the  cephalic  (really  dorsal)  end  of  the  conarium  is  cautiously 
elevated,  there  will  be  exposed  a  delicate  membrane,  the  aulatela, 
or  roof  of  the  aula. 

The  hemisplieres,  the  largest  portion  of  the  prosencepJialon,  con- 
stitute the  widest  part  of  the  brain  with  Menobranchus,  and  the 
longest  in  both  it  and  the  frog.  In  the  latter  they  are  compressed, 
in  the  former  depressed.  As  already  indicated,  their  caudal  ends 
flare  laterad  so  as  to  partly  embrace  the  diencephalon  and  nearly 
reach  the  optici  in  the  frog.  Their  mesal  surfaces  are  in  contact, 
but  may  be  separated  in  the  cephalic  part  by  blowing  between 
them  or  by  a  beaded  bristle. 

At  the  cephalic  end  of  each  hemisphere  is  attached  the  corre- 
sponding Lohus  olfactorius,  the  lateral  half  of  the  rJiinenceplialon. 
Tlie  Nerm  olfactorii  may  be  traced  thence  to  the  nasal  capsules. 
The  lobes  are  separate  in  Menobranchus  as  in  most  Vertebrates, 
but  in  the  frog  and  other  Anura  they  are  united  by  connective  tis- 
sue constituting  a  pseudo-commissura. 

§  1096.  Dissection  of  the  Amphibian  Brain. — The  arachnoidea 
and  the  metaiela  have  been  removed  as  directed  in  §  1095. 

Instruments  and  Material. — Tripod  magnifier  ;  fine  forceps  ; 
beaded  bristles  ;  very  sharp  scalpel,  preferably  small ;  fine  scissors ; 
syringotome  or  tracer  ;  flexible  blowpipe  (§  138) ;  alcohol  or  glycerin 
as  directed  in  §  1094. 

Note  at  the  bottom  of  the  metacoelia  a  mesal  furrow,  which  is 
continuous  caudad  Avith  the  canalis  centralis  of  the  myelon. 

With  the  flexible  blowpipe,  blow  cephalad  under  the  cerebel- 
lum., and  note  that  all  the  parts  of  the  brain  are  inflated,  showing 
the  existence  of  a  continuous  series  of  cavities,  as  represented  in 
Fig.  110. 


DISSECTION    OF    THE    AMPHIBIAN   BBAIN.  421 

\  With  the  scalpel  previously  dipped  in  alcohol,  or  with  the  fine 
scissors,  cut  off*  obliquely  the  latero-caudal  angle  of  the  left  hemi- 
sphere. This  exposes  the  corresponding  procoelia,  and  blowing 
into  it  inflates  all  the  other  parts.  With  the  scissors,  remove  the 
entire  latero-dorsal  wall  of  the  hemisphere,  noting  its  extension, 
rhinoccBlia,  into  the  base  of  the  Lohus  olfactorius. 

Blow  gently  upon  the  mesal  wall  of  the  hemisphere  at  about  its 
middle,  and  note  the  presence  of  an  orifice  through  which  air  passes 
into  the  other  coelise  ;  this  is  the  left  porta  or  "foramen  of  Monro." 
Note  the  continuity  of  the  hemisphere  wall  at  all  other  points. 


Wyman  mentions  (34,  15),  but  does  not  figure,  another  opening  from  the  procoelia 
rsacl  of  the  thalamus ;  this,  as  he  suggests,  would  probably  correspond  with  the  rima  or 
fissure  of  Bichat."  It  could  not  appear  until  after  the  removal  of  the  pia,  and  we  have 
t  satisfied  ourselves  of  its  existence. 


I 

^H    Pass  the  beaded  bristle  through  the  porta  toward  the  opposite 
^^emisphere,  and  note  that  it  enters  the  other  procoelia,  as  indicated 
by  the  protrusion  of  its  wall  at  some  point. 

Just  cephalad  of  the  porta  is  an  elliptical  raised  surface  which 
is  thought  by  some  (Wyman,  34,  15)  to  represent  the  striatum  of 
the  higher  Vertebrates,  but  there  is  doubt  upon  this  point. 

In  Menobranchus  the  porta  is  partly  filled  by  a  plexus  which  extends  cephalad  in  the 
procoelia ;  this  is  the  proplexus,  which  may  be  snipped  off  with  the  scissors,  but  never 
pulled  upon.  The  porta  is  much  longer  than  in  the  frog,  but  there  is  no  thickening  of 
the  mesal  wall  of  the  hemisphere  like  the  supposed  striatum  of  the  frog. 

With  the  scalpel,  remove  the  lateral  prominence  of  the  left  opti- 
cus^ and  note  that  a  somew^hat  expanded  lateral  portion  of  the 
mesoccelia  communicates  by  a  constricted  orifice  with  the  mesal 
portion  and  so  with  the  corresponding  expansion  in  the  right  opti- 
cus. Then  remove  the  dorsal  wall  of  the  entire  mesoccelia  with  the 
scalpel  and  scissors,  and  note  the  marked  folding,  the  valvula,  by 
wliich  the  cerebellum  is  continuous  therewith.  Pass  a  bristle  ven- 
trad  of  the  cerebellum  into  the  mesoccelia,  and  then  sinistro-cepha- 
lad  through  the  diacoelia  so  as  to  emerge  in  the  left  procoelia. 

Slice  off  the  caudal  part  of  the  diaccelian  roof,  including  the  part 
known  as  postcommissura.  Note  that  the  walls  (thalami)  are  quite 
thick  and  nearly  in  contact,  but  that  the  interval  is  a  nearly  simple 
vertical  fissure  and  not  a  wide  and  partly  divided  cavity  like  the 
mesoccelia.  Pas§  a  bristle  caudo-ventrad  so  as  to  enter  the  hy- 
pophysis. 


422  ANATOMICAL    TECHNOLOGY. 

By  placing  the  bead  of  the  bristle,  or  the  tip  of  the  tracer  or 
syringotonie,  in  the  cephalic  part  of  the  diaccelia,  note  that  the  roof, 
diatela,  is  partly  membranous  and  partly  formed  by  the  thickening 
known  as  the  conarium  (§  1084). 

Then  slice  away  the  thalami  to  a  still  lower  level  so  as  to  expose 
the  diaccelian  floor.  Note  that  it  is  depressed,  and  bounded  caudad 
and  cephalad  by  transverse  ridges  ;  also  that  there  are  no  plexuses 
therein. 

Slice  off  both  hemispheres  to  the  level  of  the  conarium.  Then 
remove  another  slice,  including  the  conarium  and  the  aulatela  upon 
which  it  rests.  This  will  expose  a  wedge-shaped  cavity,  the  aula, 
which  is  bounded  as  follows :  caudad,  by  the  ridge  mentioned 
above  as  the  cephalic  boundary  of  the  diacoelia  ;  laterad,  by  the 
portce  whose  length  nearly  coincides  with  its  own  ;  cephalad,  by  the 
terma,  a  lamina  of  nervous  tissue  uniting  the  mesal  walls  of  the 
hemispheres  at  the  cephalic  end  of  the  portse ;  (the  terma  is  more 
easily  seen  if  the  left  L.  ol.  and  cephalic  end  of  the  hemisphere 
are  gently  pushed  away  from  the  right)  ;  dorsad,  by  the  aulatela, 
the  atrophied  continuation  of  the  terma. 

If  the  mesal  wall  of  the  left  hemisphere  be  removed,  the  extent 
and  form  of  the  right  porta  may  be  seen. 

§  1097.  With  Menobranchus  the  conditions  are  so  different  as 
to  require  special  directions  : — 

Introduce  a  scissors  blade  just  caudad  of  the  cerebellum  on 
either  side,  and  cut  cephalad  to  the  caudal  end  of  the  hemisphere  ; 
do  the  same  on  the  other  side,  and  turn  the  flap  so  formed  cephalad 
upon  the  hemispheres.  This  exposes  the  epi-,  meso-  and  diaccBlia. 
Note  that  the  lateral  walls  are  thicker  than  the  roof,  and  that  the 
ental  surface  of  the  roof  presents  a  slight  transverse  ridge  which 
indicates  the  division  between  the  diencephalon  and  the  mesen- 
cephalon. 

The  floor  of  the  mesocoelia  is  nearly  level,  and  its  cephalic  mar- 
gin overhangs  the  passage— the  canal  of  the  infundibulum — leading 
to  the  JiypopTiysis. 

In  the  diacoelia  lie  side  by  side  a  pair  of  string-like  plexuses — the 
diaplexuses — which  are  attached  to  the  aulatela  or  diatela  and  ex- 
tend the  whole  length  of  the  cavity.  They  should  be  drawn  to  the 
sides  or  cut  off,  but  not  pulled  upon  at  all.  The  floor  of  the  diacoelia 
is  then  seen  to  be  irregular,  sloping  from  each  side  to  a  mesal  furrow. 


REMOVAL     OF    THE    BRAIN.  423 

The  cephalic  end  of  the  'diaccelia  is  decidedly  narrowed,  and  the 
walls  are  thin. 

§  1098.  Remove  the  basis  cranii  so  as  to  expose  the  basis  en- 
cepTiali  as  far  as  the  aula.  Observe  the  sub-cordate  hypophysis 
underlying  the  mesencephalon,  but  attached  by  its  base  to  the 
slight  intumescence — the  tuber  cinereum — forming  the  floor  of  the 
diencephalon. 

In  case  more  tlian  one  brain  is  examined,  the  second  sliotdd  be  transected  with  a 
very  sharp  scalpel,  and  drawings  made  to  show  the  form  of  the  coelise  at  different 
points.  A  third  brain  may  be  divided  upon  the  meson,  and  a  fourth  opened  from  the 
ventral  side.  With  all  of  these  the  metatela  should  be  left  in  place.  Still  others  may  be 
prepared  to  show  special  points.  When  many  brains  are  available,  each  should  be  devoted 
to  a  ^iven  section  or  dissection,  all  other  parts  being  untouched,  so  that  the  special  fea- 
tures may  be  more  easily  recognized. 

REMOVAL  OF  THE  BRAIN  OF  THE  CAT. 

§  1099.  The  method  first  described  is  to  be  preferred  when  the 
brain  is  wanted  entire,  and  especially  when  the  length  of  the  nerve 
roots  is  an  object ;  see  Wilder,  11. 

Instruments  and  Materials. — Medium  scalpel,  Charri^re  scalpel;  arthrotome;  tracer; 
curved  scissors  ;  bone  scissors ;  forceps ;  nippers,  medium  or  large  and  small ;  large  tray 
for  the  cat ;  small  tray,  or  a  folded  cloth,  for  the  head ;  block  ;  small  towel,  or  piece  of 
muslin,  for  aiding  the  grasp  of  the  head  ;  waste  paper ;  basin  and  towel ;  dish  of  7  per 
cent,  brine,  about  6  cm.  deep  and  20  wide,  containing  some  well  soaked  cotton ;  bowl  of 
normal  salt  solution  (15  grams  of  salt  to  2000  cc.  of  water),  sufficient  to  cover  the  head 
after  its  separation  from  the  body)  ;  bowl  for  catching  the  blood  ;  glass  box  (§  307) ;  wide 
mouthed  jar  or  covered  dish  of  63-67  per  cent,  alcohol,  with  some  well  soaked  cotton  at  the 
bottom  ;  a  cat's  skull ;  figure  of  the  hems  cranii  (Fig.  57) ;  figure  of  the  hasis  encephali 
(Fig.  115,  PL  II,  Fig.  3) ;  Table  of  the  cranial  foramina  (§  562). 

§  1100.  Killing  the  Cat. — The  cat  may  be  drowned,  but  is  more  conveniently  anaes- 
thetized (§  192).  Kill  the  fleas  as  directed  in  §  193.  As  soon  as  respiration  ceases,  sus- 
j>end  it  by  the  head  over  a  pail  or  the  sink,  and  expose  and  divide  the  femoral  artery  and 
vein  (Fig.  39)  centrad  of  the  valves  in  the  vein  (§  362) ;  even  if  little  blood  escapes,  the 
amount  in  the  brain  will  be  reduced.  If  it  be  desired  to  ascertain  the  weight  of  the  entire 
animal,  the  blood  should  be  caught  in  the  bowl  and  weighed. 

For  injection  with  alcohol,  see  §§  284,  285. 

For  injection  of  the  plexuses,  see  §  1126. 

If  the  more  delicate  internal  parts  or  the  microscopic  structure  are  to  be  studied,  the 
remaining  operations  for  the  procurement  of  the  brain  should  be  performed  within  24 
hours.  But  if  the  specimen  is  desired  only  for  the  fissures  or  the  coarser  anatomy,  re- 
moval may  be  deferred  for  a  week,  provided  the  head  be  kept  in  a  cool  place.  It  should 
not,  however,  be  allowed  to  freeze. 

§  1101.  Decapitation. — From  the  dextral  angle  of  the  mouth  di- 
vide the  skin  along  a  line  extending  nearly  caudad  for  6-8  cm.    if 


424  A  XA  TO. VIC  A  L     TE  CIINOL  0  G  Y. 

the  skin  is  to  be  mounted,  this  should  be  the  only  incision,  and  the 
skin  must  be  dissected  from  the  mandible  as  well  as  from  the  rest 
of  the  head.  But  if,  as  is  more  often  the  case,  the  skin  is  not  to  be 
preserved,  while  the  vessels  and  nerves  of  the  neck  are  to  be  exam- 
ined, make  a  corresponding  incision  from  the  angle  of  the  mouth 
upon  the  opposite  side. 

In  all  subsequent  operations,  unless  otherwise  stated,  both  sides 
are  to  be  treated  alike. 

Dissect  the  skin  from  the  maxilla  as  far  as  the  ventral  margin 
of  the  orbit  and  cut  the  nasal  cartilages.  Dissect  the  skin  from  the 
nasal  and  frontal  regions,  including  the  dorsal  and  ventral  lids  but 
leaving  the  third  lid,  Membrana  nictitans^  attached  to  the  ball. 
Kemove  the  skin  from  the  rest  of  the  head,  dividing  the  meatus 
audiiorius  close  to  the  head.  The  parotid  gland  (Fig.  87)  will  be 
removed  with  the  ear,  but  the  submaxillary ,  of  a  darker  color,  will 
remain  with  the  head.  Reflect  the  skin  from  the  cervical  muscles 
for  about  2  cm.  caudad  of  the  crista  lamhdoidalis. 

With  the  arthrotome,  dissect  the  origin  of  the  M.  massetericus 
from  the  zygoma^  noting  that  its  cephalic  and  caudal  borders  are 
strengthened  by  tendinous  bands  which  must  be  cut  (§  596,  19). 
Push  a  nipper  blade  between  the  eyeball  and  the  cephalic  root  of 
the  zygoma,  and  nip  the  latter  as  close  as  possible  to  the  maxilla. 
Then  nip  the  caudal  root  at  the  angle  between  the  transverse  and 
longitudinal  parts  of  the  zygoma,  just  laterad  of  the  Fossa  glenoi- 
dalis  ;  remove  the  zygoma  with  the  bone  scissors. 

Grasp  the  lateral  aspect  of  the  eyeball  with  the  forceps,  and 
rotate  it  mesad  so  as  to  expose  its  attachments,  by  the  muscles  and 
N.  opticus^  to  the  bottom  of  the  orbit ;  cut  the  attachments  with 
scissors,  leaving  the  Mb.  nictitans  connected  with  the  ball.  If  the 
eyes  are  to  be  studied  or  preserved,  mark  them  right  and  Itft  by 
numbers  or  tags ;  the  proper  position  is  always  indicated  by  the 
Mb.  nictitans  ;  see  Chap.  XI. 

Slightly  ventriduct  the  mandible  and  move  it  from  side  to  side 
60  as  to  indicate  the  position  of  the  Arthron  temporo-mandibulare. 
Usually  the  capsule  has  been  opened  already  in  nipping  the  caudal 
root  of  the  zygoma.  If  not,  it  is  to  be  cut  while  on  the  stretch  by 
inserting  the  arthrotome,  and  cutting  until  separation  is  complete 
on  that  side. 

Dissect  the  M.  temporalis  from  its  cranial  origin,  and  then 
from  its  insertion  upon  the  Processus  coronoideus  of  the  mandible. 


EXPOSURE     OF    THE    BRAIN.  425 

Bring  the  mandible  to  a  right  angle  with  the  rest  of  the  head,  and 
divide  the  soft  parts  at  the  angles  of  the  mouth  if  any  remain.  In 
doing  this,  insert  the  arthrotome  sidewise  so  that  it  may  pass 
between  the  Pre.  coronoideus  and  the  projection  left  after  the 
removal  of  the  cephalic  root  of  the  zygoma. 

Feel  for  the  caudal  border  of  the  hard  palate  and  for  the  tips  of 
the  Ossa  pterygoidea  (Fig.  57) ;  at  a  point  midway  between  push 
a  scissors  blade  entad  of  the  soft  palate,  and  divide  it ;  then  divide 
the  mucosa  forming  the  dorsal  wall  of  the  postnares^  and  dissect  it 
up  as  far  as  the  atlas. 

The  mandible  is  now  attached  to  the  rest  of  the  head  by  some 
muscular  fasciculi  and  by  the  slender  piers  of  the  hyoid  arch  (Fig. 
30,  §  224).  These  last  join  the  skull  at  the  lateral  side  of  the  bullae, 
where  they  are  to  be  divided  with  the  arthrotome  ;  if  it  be  desired 
to  examine  the  mode  of  their  attachment,  they  may  be  cut  with  the 
bone  scissors  at  a  little  distance  from  the  attachment. 

Yentriduct  the  tip  of  the  mandible  still  farther,  and  dissect  off 
the  muscles,  rectus  anticits  capitis  (§  628),  that  are  inserted  between 
the  bullse  ;  near  the  caudal  ends  of  the  mesal  borders  of  the  builse 
emerge  several  nerves,  which  should  be  divided  with  the  scissors  or 
a  sharp  scalpel  at  about  1  cm.  from  the  skull.  By  continuing  the 
removal  of  the  muscles  across  the  Arth.  atlobido-occipitale  this  is 
exposed.  Put  the  membranes  upon  the  stretch,  and  divide  them 
with  a  Charriere  scalpel  along  the  cephalic  border  of  the  atlas. 
This  exposes  the  myelon,  which  is  to  be  divided  in  the  same  way. 
The  remaining  ligaments  and  the  cervical  muscles  may  be  cut  with 
the  arthrotome,  and  the  skull  proper  is  then  separated  from  the 
rest  of  the  body.  Place  the  skull  in  the  normal  salt  solution,  and 
wash  the  hands  and  the  instruments  which  have  been  used. 

§  1102.  Exposure  of  the  Brain.— In  the  later  stages  of  the  ope- 
ration there  is  considerable  risk  of  injuring  the  brain  by  the  unin- 
tentional pressure  of  the  nippers. 

In  whatever  way  the  bone  is  grasped,  when  force  is  applied,  the  tendency  is  to  approxi- 
mate the  cutting  edges  as  nearly  as  possible,  and  thus  to  bring  their  planes  into  right 
angles  with  the  surface  of  the  bone.  This  of  course  crowds  the  convexity  of  the  ental 
blade  against  the  brain,  and  may  crush  it  seriously.  It  may  occur  either  from  the  turn- 
ing of  the  nippers  in  the  hand,  or  more  frequently  from  the  escape  of  the  skull  from  the 
grasp  of  the  other  hand.  The  accidents  may  usually  be  avoided  by  keeping  the  danger  in 
mind,  by  having  the  right  hand  dry,  and  aiding  the  grasp  of  the  more  or  less  slippery 
skull  by  a  small  towel  or  bit  of  coarse  muslin  ;  this  last  is  also  desirable  during  some 
stages  of  the  operation  as  a  protection  of  the  hand  itself  from  abrasion. 


426  ANATOMICAL    TECHNOLOGY. 

In  using  the  nippers,  another  precaution  is  to  be  observed.  If  the  bit  of  bone  to  be 
removed  is  attached  only  to  bone,  it  may  be  either  cut  or  broken  or  twisted  off ;  but  if  it 
adheres  to  the  dura  or  other  soft  parts,  only  cutting  should  be  employed  ;  it  is  safer  to 
use  the  bone  scissors  after  nipping  the  bone. 

When  any  bit  of  the  skull  is  broken  off,  lift  it  very  carefully,  and  examine  its  ental 
aspect  for  nerve  attachments. 

During  the  exposure  of  the  brain,  the  head  should  be  frequently  dipped  into  the  n.  s.  s. 
If  obliged  to  suspend  the  operation  for  more  than  an  hour,  wrap  the  head  in  a  cloth  wet 
with  the  n.  s.  8.,  and  set  in  a  cool  place. 

Trim  off  the  soft  parts,  including  the  meatus  auditorius.  Nip 
off  the  caudal  root  of  the  zygoma,  including  the  Fs,  mandihularis. 
Insert  a  nipper  blade  into  the  meatus  auditorius^  and  remove  the 
bulla  in  fragments.  With  the  scissors,  cut  away  the  membranes 
attached  to  the  margin  of  the  Fm.  magnum, 

Nip  off  the  occipital  condyles,  with  the  intervening  area  of  the 
hasioccipital  for  2-3  mm.  from  the  foramen.  Insert  a  nipper  blade 
between  the  dura  and  the  bone  5-Q  mm.  from  the  meson  and  in  line 
with  the  mesal  border  of  the  cephalic  part  of  the  bulla,  and  nip  out 
the  basioccipital  as  far  as  the  middle  of  the  length  of  the  bulla. 

At  or  near  the  angle  left  after  the  removal  of  the  condyle  and 
the  basioccipital,  the  N.  hypoglossus  enters  the  Fm.  cond^ylare,  and 
passes  cephalad  to  emerge  on  the  ventral  aspect  of  the  skull  by  the 
Fm,  jugulare.  If  the  series  of  roots  do  not  appear,  carefully  re- 
move a  little  more  bone  until  they  do.  If  the  nerve  roots  are  to  be 
specially  studied,  endeavor  to  nip  off  the  bone  surrounding  the 
Fm.  condylare^  so  as  to  save  the  trunk.  On  emerging  upon  the 
ventral  aspect  of  the  skull,  the  iV.  hypoglossus  will  be  found  to  lie 
very  near  the  Fm.  jugulare,  and  to  be  more  or  less  intimately 
attached  to  the  WW.  glossopJiaryngeus,  vagus  and  accessorius, 
which  penetrate  the  bone  by  that  foramen.  In  attempting  to  sepa- 
rate the  W.  hyp.,  great  care  must  be  used  to  avoid  any  traction  upon 
the  roots,  which  readily  pull  out  of  the  medulla. 

Of  the  other  three  nerves,  the  accessor ius  is  the  most  caudal, 
and  the  most  readily  distinguished,  but  at  this  stage  it  is  as  well  to 
leave  them  together,  simply  endeavoring  to  remove  the  bone  sur- 
rounding the  foramen,  and  to  save  the  trunks  pretty  long,  at  least 
upon  one  side.  Upon  the  other,  it  will  save  time  to  cut  the  roots 
just  entad  of  the  skull,  and  the  same  may  be  done  on  one  side  with 
the  remaining  nerves,  or  with  all  upon  both  sides  in  case  the  brain 
is  not  to  be  employed  for  the  study  of  the  ectal  nerve  origins. 

The  dorsal  wall  of  the  bulla  is  hard,  but  readily  crumbles  be- 


EXPOSURE    OF    THE    BRAIN.  427 

tween  the  nippers.  It  may  be  removed  in  small  pieces,  so  as  to 
save  the  WJSf.  facialis  and  auditorius  which  enter  the  Meatus 
auditorius  internus^  and  the  little  Lobulus  appendicularis  of  the 
cerebellum  which  is  lodged  in  a  slight  fossa  {Fs.  ap.)  just  dorsad 
of  the  meatus  (Fig.  59,  M.  a.  i.). 

Since  no  nerves  are  transmitted  by  the  mesal  region  of  the  basis 
cranii,  it  may  be  removed  with  comparative  freedom  as  far  cephalad 
as  the  sella  (Fig.  59),  where  some  care  is  needed  to  avoid  injuring 
the  Tiypopliysis  (Fig.  88,  Hy.). 

The  skull  may  now  be  held  more  securely  by  the  facial  region, 
especially  if  a  towel  is  employed.  In  removing  the  bone  at  each 
side  of  the  meson,  and  just  cephalad  of  the  bullee,  great  care  is 
required  to  disengage  the  nerves  which  emerge  by  the  Fm.Fin.  ovale^ 
rotundum  and  lacerum  anterius.  These  nerves,  the  NN.  oculomo- 
torius,  troclilearis  and  dbducens^  with  the  ophthalmic,  superior 
maxillary  and  inferior  maxillary  divisions  of  the  N.  trigeminus, 
penetrate  the  bone  more  or  less  obliquely,  and  are  closely  sur- 
rounded by  dense  connective  tissue. 

The  entire,  maxilla  is  now  to  be  removed  by  first  nipping  the 
interorbital  region  just  cephalad  of  the  fronto-maxillary  suture,  and 
then,  with  the  bone  scissors,  cutting  toward  this  point  from  just 
caudad  of  the  cephalic  root  of  the  zygoma.  The  scissors  should  be 
kept  as  far  cephalad  as  possible,  so  that  the  LoM  olfactorii  may 
not  be  injured.  This  plan  serves  equally  well  for  some  dogs,  but 
with  the  larger  breeds,  which  have  prominent  olfactory  lobes,  the 
interorbital  region  should  be  nipped  at  about  the  middle  of  the 
length  of  the  nasal  bones. 

§  1103.  Remove  the  mesal  wall  of  the  orbit  and  the  turbinated 
bones,  using  care  not  to  crush  the  very  soft  Lobi  olfactorii.  The 
olfactory  nerves  should  be  divided,  a  few  at  a  time,  with  the  scissors 
or  the  tip  of  the  scalpel,  and  all  pulling  and  twisting  of  the  parts 
must  be  avoided. 

The  large  and  white  Nerm  optici  will  have  been  seen  in  the 
orbit,  and  should  be  divided  near  the  bone.  In  removing  the  plate 
(Fig.  60)  upon  which  the  chiasma  rests,  use  care  not  to  pull  upon 
it,  lest  the  terma  or  other  delicate  parts  should  be  torn. 

During  the  remaining  steps  of  the  operation,  the  head  must  be 
held  by  the  parietal  regions,  and  with  great  care,  so  as  to  avoid 
pressure  of  the  tips  of  the  fingers  upon  the  brain.  The  bone  also 
must  now  be  cut  by  the  nippers  rather  than  twisted  or  broken. 


438  ANATOMICAL     TECHNOLOGY. 

]S"ip  off  the  supraoccipitale^  including  the  dura,  as  far  as  the 
Crista  lambdoidalis.  Then  nip  off  the  crista  itself  in  its  whole 
extent  (intil  the  attached  border  of  the  bony  tentorium  is  seen  to  be 
free  from  the  parietalla.  Then  divide  the  ventral  ends  of  the  ten- 
torium as  follows  : — 

Hold  the  head  with  the  ventral  side  down,  support  the  caudal 
divisions  of  the  brain  with  a  disengaged  linger,  and  with  tracer  and 
scissors  separate  the  cephalic  surface  of  the  cerebellum  from  the 
tentorium. 

Introduce  a  nipper  blade  between  it  and  the  hemisphere  on 
either  side,  in  such  a  way  that  the  greater  convexity  is  toward  the 
hemisphere  rather  than  the  cerebellum ;  the  cut  is  to  be  made  at 
the  level  of  the  Sutura  squamosa ;  the  width  of  the  tentorium  at 
this  point  is  about  8  mm.,  and  the  nijjper  blade  should  not  be  intro- 
duced to  a  greater  depth  than  that,  for  fear  of  injuring  the  optici. 
In  closing  the  blades,  the  head  should  be  held  very  firmly  so  that 
no  rotation  may  occur.  The  detached  tentorium  may  be  extracted 
by  the  forceps,  or  by  the  nippers  used  as  forceps,  any  adhesions 
being  carefully  separated  with  the  tracer  or  scissors. 

Hold  the  head  over  the  7  per  cent,  brine,  with  the  ventral  side 
down,  and  nip  out,  piecemeal,  a  triangular  piece  of  the  calva. 
The  mesal  adhesions  of  the  dura  may  be  divided  with  the  scissors, 
but  elsewhere  the  dura  is  to  be  left  upon  the  hemispheres.  As  the 
hemispheres  begin  to  fall,  hold  the  head  so  that  they  are  supported 
by  the  brine,  and  then  snip  all  remaining  adhesions  until  the  entire 
brain  is  free  and  floats  in  the  liquid. 

§  1104.  Removal  of  the  Dura. — Saturate  some  cotton  with  the 
brine,  and  place  it  under  the  brain,  so  that  about  one  third  of  the 
organ  projects  above  the  surface.  Avoid  Tiandling  and  lifting  the 
hrain;  move  it  by  shifting  the  cotton  or  by  grasping  the  dorsal  por- 
tions of  the  dura.  Remove  the  dorsal  and  lateral  parts  of  the  dura 
by  grasping  the  free  borders  left  by  cutting  along  the  dorsimeson, 
and  cutting  out  piece  by  piece  with  the  scissors.  Then  grasp  the 
falx  just  dorso-caudad  of  the  Lohi  ol.^  at  the  straight  transverse 
Assure — F.  cruciata  ;  introduce  the  scissors  about  5  mm.,  and  cut 
the  falx.  Gently  draw  the  cephalic  portion  cephalo-ventrad  be- 
tween the  Ldbi  ol.,  and  remove  it.  Draw  the  caudal  portion  cau- 
dad,  and  carefully  cut  aU  its  attachments. 

Turn  the  brain  upon  its  dorsal  surface,  and  remove  the  ventral 
portions  of  the  dura  with  great  care  and  in  small  pieces.    Especial 


REMOVAL    OF    THE    PIA.  429 

pains  are  needed  in  connection  with  tiie  hypophysis  and  the  nerves, 
and  all  pulling  must  be  avoided.  On  one  side,  at  least,  it  is  well  to 
leave  the  dura  still  attached  to  the  nerves  and  the  great  Gasserian 
ganglion  upon  the  N.  trigeminus  (Fig.  115 ;  Plate  II,  Fig.  3,  Gn.  G.), 
to  be  more  completely  removed  at  the  time  of  the  removal  of  the  pia. 

§  1105.  Trajisfer  to  the  Alcohol. — Place  a  large  spoon  or  watch 
glass  at  the  side  of  the  brain,  and  pull  the  cotton  which  supports  it, 
so  as  to  roll  it  into  the  glass,  resting  upon  its  dorsum.  Let  the 
brain  slide  from  the  glass  into  the  alcohol  so  as  to  rest  upon  the 
cotton  therein,  still  with  the  ventral  side  up. 

Set  the  bowl  with  the  alcohol  in  a  cool  place,  and  change  the 
position  of  the  brain  at  intervals  of  5-10  hours  during  the  first  three 
days,  by  pulling  the  cotton  in  various  directions.  At  the  end  of 
about  three  days,  transfer  the  brain  to  95  per  cent,  alcohol,  where  it 
may  remain  indefinitely.  For  a  few  days,  however,  it  should  rest 
upon  cotton,  and  its  position  be  occasionally  changed.  For  the 
management  of  alcohol  employed  in  the  preservation  of  brains,  see 
§§  286^  296. 

§  1106.  Weighing  the  Brain.— If  this  is  to  be  done,  handling  of 
the  brain  may  be  avoided  as  follows :  Place  the  bowl  of  alcohol 
into  which  the  brain  is  to  be  put  upon  the  scales,  and  pour  in  alco- 
hol of  the  same  strength  until  it  balances  an  even  number  of  grams, 
e,  g.^  400,  410  or  420.  While  the  brain  is  in  the  spoon  or  watch 
glass,  pour  over  it  some  of  the  same  alcohol,  and  then  let  the  latter 
drain  off  as  much  as  possible  by  tilting  the  glass  and  supporting 
the  brain  with  the  fingers  or  a  bit  of  cotton.  Then  transfer  to  the 
bowl  of  alcohol  as  above  directed,  and  the  increase  in  weight  will 
represent,  with  approximate  accuracy,  the  weight  of  the  brain. 

§  1107.  Removal  of  the  Pia.— This  is  most  easily  accomplished 
at  the  time  of  the  removal  of  the  brain  to  the  stronger  alcohol.  At 
any  subsequent  period  the  pia  is  apt  to  be  more  firmly  adherent. 
If  the  brain  has  been  allowed  to  dry  at  all  during  its  removal  from 
the  skull,  the  pia  comes  off  with  great  difficulty,  or  parts  of  the 
cortex  are  torn  off  with  it. 

§  1108.  Instruments  and  Materials. — Coarse  and  fine  forceps  ; 
medium  or  fine  scissors  ;  wetting  bottle  of  15  per  cent,  glycerin  ; 
cotton  thoroughly  wet  with  water,  and  so  molded  as  to  form  a  sort 
of  shallow  cup  in  which  the  brain  may  be  grasped,  or  on  which  it 
may  rest  without  danger  of  rolling  off. 

Place  the  brain  upon  the  cotton,  and  wet  it  with  the  glycerin. 


430  ANATOMICAL    TECHNOLOGY. 

Then  let  it  rest  upon  its  ventral  side,  and  grasp  it  in  the  cotton, 
firmly  yet  gently.  Grasp  with  the  forceps  the  fold  of  'pia  which 
occupies  any  one  of  the  lissures,  especially  at  the  point  of  forking 
or  junction  with  another  fissure,  and  pull  along  the  line  of  the 
fissure.  Usually  the  fold  of  pia  will  come  out  easily,  and  with  it 
will  be  removed  some  of  the  pia  covering  the  free  surface  of  the  gyri 
between  it  and  the  adjoining  fissures. 

Proceed  thus  until  the  pia  has  been  removed  from  the  dorsal 
and  lateral  aspects  of  the  hemispheres.  Avoid  pulling  across  the 
line  of  the  fissures.  The  larger  forceps  are  easier  to  work  with,  and 
less  apt  to  puncture  the  brain ;  but  the  fine  forceps  are  sometimes 
required  for  the  removal  of  the  pia  from  the  bottom  of  a  deep  fissure. 
The  caudal  surface  of  the  hemispheres  may  be  reached  by  slightly 
ventriducting  the  cerebellum.  The  mesal  pia  can  be  removed  only 
at  the  margins  of  the  hemispheres. 

On  one  side,  preferably  that  on  which  the  N.  opticus  w^as  cut 
shorter,  raise  the  mass  of  nerves  formed  by  the  divisions  of  the  NN, 
trigeminus  and  dbducens  by  its  lateral  border,  and  cut  with  the 
scissors  the  N.  oculomotorius  which  holds  the  mesal  border  close  to 
the  brain.  This  will  permit  the  mass  to  be  turned  caudad  so  as  to 
expose  the  course  of  the  slender  N.  trocTilearis  which  emerges  from 
between  the  hemispheres  and  the  cerebellum.  It  also  permits  the 
removal  of  the  pia  from  the  region  just  laterad  of  the  hypophysis. 
Grasp  the  pia  on  the  ventrimeson  just  caudad  of  the  Lohi  ol.,  and 
pull  caudad  so  as  to  remove  it  as  far  as  the  chiasma,  taking  care 
not  to  tear  the  delicate  terma  just  dorsad  of  the  chiasma.  Tlien 
remove  the  pia  from  the  olfactory  tracts. 

In  removing  the  pia  from  the  metencephalon,  the  position  of  the 
nerve  roots  should  be  constantly  kept  in  mind,  the  tripod  (Fig.  26) 
should  be  frequently  used,  and  traction  should  be  avoided.  It  is  very 
difficult  to  presei-ve  the  delicate  funiculi  of  the  N,  Jiypoglossics,  for 
their  connection  with  the  pia  seems  to  be  closer  than  with  the  brain. 
Sometimes  it  may  be  necessary  to  submerge  the  brain  in  water  or  alco- 
hol, so  as  to  float  the  roots  out  and  render  them  more  apparent.  In 
some  cases  it  is  safer  to  cut  carefully  about  the  point  of  passage  of  the 
root  through  the  pia,  leaving  a  bit  of  the  membrane  attached  thereto. 

As  suggested  on  a  previous  page,  it  is  often  as  well  to  leave  the 
roots  longer  on  one  side  than  the  other,  but  the  choice  may  be 
determined  mainly  by  the  degree  of  success  in  the  various  opera- 
tions which  have  been  described. 


REMOVAL    OF    THE    BR  Aim  431 

§  1109.  Other  Methods  of  Removing  the  Brain. — The  following  methods  are  siru- 
[jler  and  more  expeditious  than  the  preceding,  but  less  satisfactory  in  some  respects. 

(A)  By  Nipping^  away  the  Calva  (Vault  of  the  Cranium). — This  method  is  especially 
adapted  for  the  rapid  exposure  of  the  dorsal  and  lateral  aspects  of  the  hemispheres  or  the 
cerebellum.  When,  for  example,  the  brain  of  a  recent  or  alcoholic  specimen  of  some  rare 
animal  is  believed  to  be  so  soft  that  extraction  by  the  usual  method  is  not  feasible,  a 
drawing  or  photograph  can  be  taken  so  as  to  represent  at  least  the  form,  and  the  arrange- 
ment of  the  fissures. 

Instruments  and  Materials. — These  are  tlie  same  as  for  the 
method  already  described  (§  1099). 

Decapitation. — This  is  to  be  performed  as  directed  in  §  1101,  and 
the  eyes,  zygomata  and  temporal  muscles  removed. 

§  1110. — Exposure.— W\i\i  the  large  or  medium  nippers  cau- 
tiously penetrate  the  dorso-lateral  aspect  of  the  cranium,  but  with- 
out piercing  the  dura.  Pass  the  tracer  between  the  bone  and  the 
dura  at  all  sides,  keex)ing  the  point  away  from  the  brain ;  then 
remove  so  much  of  the  bone  as  is  separated.  When  the  orifice  is 
sufficiently  enlarged,  employ  the  probe  or  the  handle  of  a  scalpel 
in  place  of  the  tracer.  If  the  adhesions  along  the  meson  are  very 
firm,  remove  the  bone  on  both  sides,  and  divide  them  with  the 
arthrotome  or  scalpel. 

In  exposing  the  cephalic  part  of  the  hemispheres,  the  large 
frontal  sinuses  (Fig.  56,  59,  60,  §  524)  will  be  opened ;  note  the 
density  of  the  ectal  layer  {tabula  externa)  of  the  cranium,  and  the 
elliptical  orifices  of  the  infundibula. 

If  the  hemispheres  only  are  to  be  exposed,  or  if  it  is  desirable  to 
preserve  the  facial  region,  the  dura  may  be  divided  with  the  scis- 
sors along  the  margins  of  the  bone,  and  the  falx  (Fig.  88)  carefully 
cut  near  the  cephalic  and  caudal  ends  of  the  hemispheres,  so  as  to 
permit  the  removal  of  the  dorsal  dura.  The  lateral  aspects  of  the 
hemispheres  may  be  exposed  so  far  as  desired,  the  olfactory  crura 
(PL  I,  Fig.  2)  may  be  divided,  and  the  liemispheres  together  with 
the  parts  covered  by  them  removed  by  holding  the  head  so  that  its 
frontal  region  tends  to  fall  out,  and  successively  dividing  the  JSW. 
optlci^  the  infundibulum  and  the  other  nerves  as  they  appear  at 
the  base  of  the  brain,  and  lastly  the  crura  cerebri. 

%  1111.  Commonly,  however,  the  removal  of  the  dura  should  be 
postponed,  and  the  olfactory  lobes  should  be  carefully  exposed  by 
the  removal  of  the  thin  bones  which  surround  them  ;  this  is  of 
course  facilitated  by  removing  the  entire  maxillary  region  as  directed 
in  §  1102. 


432  AKATOMICAL     TECHNOLOGY, 

The  candal  regions  of  the  hemispheres  rest  upon  the  hony  teiv- 
torium  (Fig.  59,  88,  §  552) ;  note  that  the  dura  is  continued  upon 
its  surface  and  closely  attached,  but  quite  independent  of  it. 

Remove  the  supraocci/pitale  (§  1013),  leaving  the  dura  upon  the 
cerebellum  if  possible,  and  then  the  Crista  lambdoidaUs  and  the 
parts  of  the  parietalia  betvi^een  the  latter  and  the  attachment  of 
the  tentorium.  The  latter  may  then  be  nipped  at  each  side  as 
directed  in  §  1103,  and  the  central  part  removed.  The  tentorial 
dura  commonly  adlieres  so  closely  that  it  must  be  removed  likewise 
by  snipping  it  along  the  attached  border  of  the  tentorium.  In 
removing  it,  care  must  be  taken  not  to  injure  or  tear  away  the 
conarium  (PL  II,  Fig.  4,  en.).  The  entire  dura  so  far  as  exposed 
may  now  be  lifted  as  directed  above. 

Remove  more  of  the  right  side  of  the  skiill  so  as  to  expose  the 
Lohulus  liypocampcB  (PI.  I,  Fig.  2,  LI.  Jimp.) ;  the  perioticum  (Fig. 
59,  pro.)  should  be  cracked  with  the  nippers  and  removed  in  small 
fragments. 

§  1112.  Removal. — Hold  the  head  so  that  the  right  side  of  the 
brain  tends  to  fall  out  of  place.  The  dextral  nerves  are  to  be  di- 
vided with  the  scissors  or  small  scalpel,  beginning  with  the  most 
caudal.  If  the  hypophysis  is  to  remain  attached  to  the  brain,  the 
division  of  the  optic  and  trigeminus  nerves  should  be  deferred  until 
after  it  is  dislodged  or  the  bone  is  nipped  from  about  it.  Finally, 
the  sinistral  nerves  may  be  divided  and  the  brain  allowed  to  fall  into 
the  brine. 

§  1113.  With  some  modifications,  the  method  just  described  is  well  adapted  to  the 
removal  of  the  brain  from  young  human  subjects.  If  the  skull  cannot  be  cut  with  the 
nippers  or  bone  scissors,  it  may  be  trephined  in  various  places  and  the  intervening  areas 
broken  away.  The  dura  should  be  retained  as  long  as  possible,  and  the  entire  head  should 
be  floated  in  strong  ^brine  so  that  the  brain  may  not  bear  its  own  weight  at  all.  If  the 
head  is  still  attached  to  the  body,  the  latter  may  be  laid  upon  a  box  as  high  as  the  dish 
so  that  the  head  may  hang  over  the  side  of  the  latter. 

§1114.  (B)  By  Hemisection  of  the  Head  with  a  Saw.— The  advantages  of  this 
method  are  : — (1)  It  is  comparatively  expeditious  ;  (2)  the  skull  may  be  preserved  ;  (3)  the 
brain  may  be  hardened  in  situ,  safely  transported  if  desired  and  removed  at  a  future  time. 

The  two  following  objections  are  more  apparent  than  real : — 

(1)  The  skull  is  "  mutilated."— On  the  contrary,  for  nearly  all  purposes  of  study,  to 
halve  a  skull  is  to  double  its  value.  Even  if  it  is  to  be  mounted  with  the  skeleton  or  within 
the  ekin,  the  two  halves  may  be  readily  conjoined. 

(2)  The  brain  is  injured  by  the  saw.— If  the  hemisection  is  accurately  mesal,  the  only 
parts  really  destroyed  are  the  conarium  and  crista  ;  all  other  parts  which  cross  the  meson 
are  recognizable,  and  the  mesal  aspects  of  the  hemispheres  are  often  untouched.     If  it  be 


REMOVAL    OF    THE    BRAIN.  433 

especially  desirable  to  preserve  the  mesal  surface  of  one  liemisphere  and  the  parts  upon 
the  meson,  the  plane  of  section  may  be  1-2  mm.  laterad  (usually  sinistrad)  of  the  meson. 
The  lateral  incisor  will  be  destroyed  unless  previously  removed  ;  but  the  rest  of  the  skull 
will  be  unharmed,  and  its  meson  will  be  available  for  study. 

§  1115.  Instruments  and  Materials.  —  Tlie  same  as  for  the 
method  first  described  (§  1099),  with  the  exception  of  the  nippers^ 
and  with  the  addition  of  the  small  back  saw  (§  152)  and  the  macro- 
tome  (Appendix). 

§  1116.  Decapitation, — Remove  the  skin  as  directed  in  §  1101  ; 
if  the  skin  is  to  be  mounted,  divide  it  only  from  the  dextral  angle 
of  the  mouth. 

With  the  arthrotome  divide  the  M.  temporalis  along  the  dorsal 
margin  of  the  zygoma  and  the  caudal  margin  of  the  orbital  process 
of  the  0.  malar e^  and  dissect  up  the  muscle  for  1-2  cm. 

This  will  expose  the  end  of  the  Pre,  coronoideus  of  the  mandi- 
ble ;  cut  about  it  so  as  to  free  it  from  muscular  and  tendinous 
attachments. 

Separate  the  masseter  (Fig.  67)  from  the  ventral  border  of  the 
zygoma,  cutting  to  the  Pre,  coronoideus.  At  a  point  nearly  mid- 
way between  the  meatus  aud,  and  the  orbital  process  of  the  malar 
is  situated  the  ArtJiron  temporo-mandihulare ;  determine  its  exact 
position  by  pressing  with  the  finger  while  the  mandible  is  moved  in 
various  directions.     Open  the  arthron  as  directed  in  §  1101. 

Ventriduct  the  mandible  and  cut  any  remaining  attachments ; 
then  proceed  as  directed  in  §  1101. 

§  1117.  Mesal  Hemisectlon. — AVith  the  arthrotome  cut  between 
the  two  mesal  incisor  teeth  and  between  the  nasal  bones  ;  also  upon 
the  meson  at  the  Crista  lambdoidalis  and  the  caudal  border  of  the 
0.  hasioccipitale. 

Adjust  the  slide  so  that  when  the  head  is  forcibly  pressed  against 
it  the  cuts  just  made  coincide  with  the  slit  and  groove  of  the  macro- 
tome.  Eest  the  head  with  the  canine  teeth  in  the  rebate^  hold  the 
saw  obliquely  so  that  it  runs  in  the  slit  and  cuts  through  the  facial 
region.  Then  hold  the  saw  more  nearly  horizontal ;  finally,  place 
the  skull  flat  upon  the  board  and  complete  the  hemisection  with 
long,  steady  strokes. 

g  1118.    Lateral  Hemisection. — If  it  is  desirable  that  the  meson 

should  be  absolutely  uninjured,  remove  a  mesal  incisor,  and  make 

the  initial  guiding  cuts  through  the  periosteum  about  1  mm.  laterad 

of  the  meson,  so  that  the  saw  may  pass  through  the  vacant  socket 

28 


434  ANATOMICAL    TECHNOLOGY. 

and  tbrougli  corresponding  points  upon  the  basi-  and  supraoccipital 
bones. 

§  1119.  As  already  indicated  (§  1114),  the  brain  may  be  har- 
dened while  in  the  cranium.  Each  half  should  be  loosened  a  little 
as  presently  directed,  and  95  per  cent,  alcohol  injected  between  the 
dura  and  the  brain  at  two  or  three  points.  The  half  heads  may 
then  be  placed  in  62-67  per  cent,  alcohol  for  two  days  and  then 
transferred  to  95  per  cent. 

Usually,  however,  the  brain  should  be  removed  (§  1121),  and  the 
dish  of  alcohol  should  have  a  flat  bottom,  or  a  piece  of  flat  glass 
should  be  placed  in  it,  so  that  the  hemiencephala  may  rest  upon 
their  mesa.  The  operation  will  be  facilitated  by  reference  to  a 
hemicranium  or  to  a  figure  of  its  ental  aspect. 

§  1120.  Weighing, — (A)  Direct  method : — As  soon  as  the  hemi- 
encephala are  in  the  normal  saline  solution,  lift  them  out  by  means 
of  a  slip  (§  95),  upon  which  their  mesa  should  rest,  let  the  liquid 
drain  ofi",  and  place  them,  still  upon  the  slip,  upon  the  weighing 
pan.  Upon  the  other  pan  place  a  similar  slip  which  has  been 
dipped  in  the  same  liquid. 

(B)  Indirect  method  : — Just  before  removing  the  brain,  and  after 
snipping  off  the  falx,  weigh  the  two  halves  of  the  head.  AVeigh 
the  hemicrania  immediately  after  the  removal,  and  the  difference 
will  represent  the  weight  of  the  brain. 

§  1121.  Bemoval. — Wash  the  mesa  with  a  gentle  stream  of  water, 
or  by  movement  to  and  fro  in  a  dish  .of  water.  If  the  falx  (Fig.  88) 
is  upon  this  side,  grasp  the  edge  with  the  forceps,  and  snip  it  along 
its  attachment  to  the  skull.  Note  the  position  of  the  tentorium,  of 
the  fossa  olfactoria^  and  oii\\Q  foramina  upon  the  prepared  skull ; 
also,  upon  a  figure,  the  ectal  origins  of  the  cranial  nerves. 

Hold  the  skull  with  the  venter  upward,  and  gently  push  the 
medulla  mesad  with  the  tips  of  the  scissors.  Cut  the  JSf.  Tiypoglos- 
sus  close  to  the  dura.  Successively  cut  the  iVTV;  accessoo^ius,  vagus 
and  glossopliaryngeus  as  they  enter  the  Fm,  jugulare.  Tilt  the 
skull  so  as  to  permit  the  slight  dislodgement  of  the  meten.  and  epen. 
and  divide  tlie  NJSF.  auditorius  and  facialis  ;  this  will  allow  the 
small  Lolus  appendicularis  to  leave  its  fossa.  Cut  the  N.  ahdu- 
cens  and  the  N.  trigeminus,  with  the  tracer  and  scissors  dislodge 
the  TiypopTiysis,  and  cut  the  N,  opticus.  Lastly,  divide  the  NN. 
troclilearis  and  oculomotor ius. 


THE    ZINC    CHLORID    PROCESS.  435 

Turn  the  cephalic  end  upward,  and  very  carefully  dislodge  the 
Lohus  olf actor ius.  When  this  is  done,  the  cephalic  end  of  the 
hemisphere  will  be  easily  freed  from  the  dura.  Hold  the  skull  with 
its  venter  down  over  the  normal  salt  solution,  and  let  the  brain  roll 
into  it. 

§  1122.  Hardening. — For  a  few  hours  the  hemiencephala  should 
rest  upon  their  mesa ;  then  a  little  bed  of  absorbent  cotton  should 
be  made  for  each,  so  that  it  may  rest  with  the  meson  uppermost 
and  yet  not  be  distorted. 

After  two  days  transfer  to  95  per  cent,  alcohol,  changing  the 
position  as  above. 

§  1123.  The  Zinc  Chlorid  Process. — The  preservation  of  brains  by  means  of  a  solution 
of  chlorid  of  zinc  is  mentioned  or  more  or  less  fully  described  by  Gratiolet  (A,  II),  Bischoff 
(12,  11),  Giacomiui  {1  [abstract  in  Jour,  of  Anat.  and  Phys.,  XIII]),  Rolleston  (i)  and 
Osier  {1,  2). 

Our  own  experience  is  not  yet  sufficiently  extensive  to  enable  us  to  form  an  opinion 
respecting  its  merits,  and  we  here  give  (slightly  modified  verbally)  the  condensed  direc- 
tions which  accompanied  the  admirable  preparations  of  the  human  brain  exhibited  by 
Osier  at  the  raieeting  of  the  Am.  Assoc.  Adv.  Sci.,  1879,  and  substantially  reproduced  in 
Ids  second  paper  {2). 

"  (1)  Immerse  in  a  zinc  chlorid  [saturated]  solution  (*  Burnett's '  will  answer).  Turn 
two  or  three  times  a  day.  On  the  second  day  remove  the  pia.  Let  it  remain  until  it  no 
longer  sinks  (8-10  days). 

"  (2)  Immerse  in  alcohol  of  commerce  [95  per  cent.]  for  10-12  days,  turning  often  to 
prevent  distortion. 

*'  (3)  Immerse  in  good  glycerin  to  which  has  been  added  1  per  cent,  of  carbolic  acid. 
Let  it  remain  until  it  sinks  to  the  level  of  the  liquid. 

"  (4)  Set  aside  for  several  days  until  the  surface  is  dry.  Then  cover  with  several  layers 
of  gum -elastic  varnish." 

§  1124.  Injection  of  the  Codioe. — (A)  With  alcohol. — When  the  ccelise  and  plexuses  are 
to  be  studied,  it  is  an  advantage  if  the  former  have  been  first  filled  with  strong  alcohol. 
This  is  most  readily  done  after  the  entire  brain  has  been  placed  in  the  weaker  alcohol 
(§  1105). 

Gently  detach  the  hypophysis  with  the  forceps,  or  leave  it  attached  by  a  part  of  the 
infundibulum.  Then  fill  a  small  syringe  with  95  per  cent,  alcohol,  apply  the  outlet  (with- 
out a  canula)  to  the  Fm.  infundlhuU,  and  inject  slowly  until  the  LI.  hypocampa  (PI.  TI, 
Fig.  3)  is  seen  to  swell  slightly.  Repeat  the  operation  several  times  at  intervals  of  1-3 
hours. 

§  1125.  (B)  With  plaster. — This  is  for  the  sake  of  obtaining  a  cast  of  some  part  of  the 
coeliae.  It  is  best  done  while  the  brain  still  rests  in  the  calva  (§  1103).  See  description  of 
Fig.  119.  This  method  was  employed  by  us  before  Welcker's  method  of  injecting  wax  was 
known  to  us  {1  [abstract  in  Jour.  Anat.  and  Phys.,  XIII,  283]). 

After  the  injection  the  brain  should  remain  wholly  undisturbed  for  at  least  half  an  hour. 
The  parts  about  the  Fm.  infundihitli,  constituting  the  floor  of  the  diacoelia,  may  then  be 
gently  cut  away  with  scissors  so  as  not  to  break  the  cast.     It  is  probable  that  a  fracture 


436 


ANA  TOMICAL    TECHNO L  OGY. 


tvill  occur  at  tlie  portae,  but  the  parts  may  be  reunited  with  glue  and  mounted  upon  glass 
under  a  watch  glass  so  that  the  separated  parts  are  contiguous. 

i^  1126.  Injection  of  the  Plexuses. — The  larger  arteries  of  the  brain  are  filled  when 
the  cejjhalic  region  of  the  body  is  injected  with  plaster  (§§  352-367). 

For  the  special  study  of  the  plexuses,  gelatin  or  Berlin  blue  may  be  injected  from  the 
aorta  as  follows  :— - 

Expose  the  thoracic  vessels  as  directed  in  §  918,  and  note  their  positions  and  connec- 
tions as  shown  in  Fig.  101.  102. 

Ligate  the  aorta  near  its  base,  the  A.  subdavia  sinistra  near  the  aorta,  and  the  A.  sub- 
clavia  dextra  near  its  junction  with  the  A.  carotidea.  Open  the  aorta  peripherad  of  the 
place  of  origin  of  the  A.  subdavia  sinistra,  expel  any  blood,  and  inject  cephalad. 


A    MACROSCOPIC    VOCABULARY    OF    THE    BRAIN. 


§  1127.    Abbreviations  of  the  General  Names. 


Ar. — Area. 
C.-Ccelia. 
Clm. — Col  umna. 
Cn. — Canalis. 
Cp. — Corpus. 
Cr. — Crus. 
Ci'S. — Crista. 
Cs.  — Commi  ssura. 
£Jm. — Eminentia. 


i^. — Fissura. 
Fm. — Foramen. 
Fn. — Funiculus. 
Fs. — Fossa. 
Inc. — Incisura. 
L.  — Lobus. 
LI. — Lobulus. 
iV. — Nervus. 
P^.— Portio. 


Px. — Plexus. 
B. — Recessus. 
%.— Regio. 
Ex. — Radix. 

^.—Sulcus. 
Spt. — Septum. 
71— Tuber. 
TV.— Tractus. 
r^.- Tela. 


§  1128.    List  of  Abbreviations  of  the  Special  Names. 

In  this  list  are  given  only  the  names  adopted  in  this  work  ;  the  synonyms  are  given  in 
the  descriptions  which  occur  later  in  the  alphabetical  order  of  the  names. 
Tliose  marked  az.  are  mesal  or  azygous  ;  the  rest  are  in  pairs. 


a. — Aula,  az. 

abn. — Albicans,  (Corpus). 

aU). — Alba,  (Substantia). 

apx. — Auliplexus. 

arb.  vt. — Arbor  vitae,  az. 

arch. — Aracbnoidea. 

Ar.  cr. — Area  cruralis,  az. 

Ar.  icr. — Area  intercruralis,  az. 

Ar.  el. — Area  elliptica. 

Ar.  ov. — Area  oval  is. 

Ar.  ppn. — Area  postporitilis,  az. 

Ar.prch. — Area  praechiasmatica,  az. 

A  r.  spt. — Area  septalis. 

m.— Carina,  az. 

cb. — Cerebrum,  az. 

cbl. — Cerebellum,  az. 

cd.  s. — Cauda  (Corporis)  striati. 

cd.  m. — Cella  media. 

ch. — Chiasma,  az. 

cin. — Cinerea,  'Substantia). 


cl. — Callosum,  (Corpus),  az. 

etc. — Calcar.    Not  in  the  cat. 

civ. — Clava. 

Glnfi.  d. — Col  umna  dorsalis  (myelonis). 

Clm.  /.— Columna  fornicis. 

(Jim.  I. — Clm.  lateralis  (myelonis). 

Clm.  V. — Clm.  ventralis  (myelonis). 

cmb. — Cimbia. 

cn. — Conarium,  az. 

Cn.  ce. — Canalis  centralis  (myelonis),  az* 

cnt.  ov. — Centrum  ovale  (minus). 

Cr.  cb. — Crus  cerebri. 

Cr.  ol. — Crus  olfactorium. 

Crs.f. — Crista  fornicis,  az. 

Cs.f. — Commissura  fornicis,  az. 

Cs.  h. — Commissura  babenarum,  az 

ctx. — Cortex. 

d. — Dura  (mater). 
dc. — Diacoelia,  az. 
Dec.  py. — Decussatio  pyramidum. 


3IACR0SC0PIC    VOCABULARY    OF    THE    BRAIN. 


437 


(Jen. — Diencephalon,  az. 
dlt. — Delta  (fornicis),  az. 
dpx. — Diaplexus. 
dil. — Diatela,  az. 

Em.  au. — Eminentia  auditoria. 
end. — Endyma. 
epc. — Epicoelia,  az. 
epen. — Epenceplialon,  az. 

F.  a. — Fissura  anterior. 

F.  an. — Fissura  ansata. 

F.  c/.— Fissura  confinis. 

F.  d. — Fissura  callosalis. 

F.  cor. — Fissura  coronalis. 

F.  c/'.— Fissura  cruciata, 

F.  dg. — Fissura  diagonalis. 

F.  dl. — Fissura  dorsilateralis  (myelonis). 

F.  dms. — Fissura  dorsimesalis  (myelonis), 

az. 
F.  fm. — Fissura  fimbriag. 
F.  fl. — Fissura  falcialis, 
F.  hmp. — Fissura  hippocampalis. 
F.  in. — Fissura  intermedia. 
F.  I. — Fissura  lateralis. 
F.  In. — Fissura  lunata. 
F.  ml. — Fissura  medilateralis. 
F.  mr. — Fissura  marginalis. 
F.  ol. — Fissura  olfactoria. 
F.  p. — Fissura  postica. 
F.  per. — Fissura  postcruciata. 
F.  pmr. — Fissura  postmar  gin  alls. 
F.  prd. — Fissura  postradi calls. 
F.  prh. — Fissura  postrliinalis. 
F.  prrd. — Fissura  prseradicalis. 
F.  p«.— Fissura  postsylviana. 
F.  rh. — Fissura  rhinalis. 
F.  s. — Fissura  Sylviana. 
F.  sfl. — Fissura  subfalcialis. 
F.  sp. — Fissura  splenialis. 

F.  so. — Fissura  superorbitalis. 

F.  ss. — Fissura  supersylviana. 

JT^  q^l — Fissura  ventrilateralis  (myelonis). 

F.  vms. — Fissura  ventrimesalis  (myelonis), 
az. 

f. — Fornix,  az. 

flc. — Flocculus. 

Fm.  ce. — Foramen  caecum,  az. 

Fni.  en. — Foramen  conarii,  az. 

Fm.  inf. — Foramen  infundibuli,  az. 

fmh.  —  Fimb  ria . 


fscl. — Fasciola. 

g. — Genu,  az. 

h. — Habena. 

Jiem. — Hemisphaera. 

hmp.  — Hippocampus. 

hmspt. — Hemiseptum  (cerebri). 

Aj?/i.— Hypophysis,  az. 

Inc.  hmp. — Incisura  hippocampi. 

inf. — Infundibulum,  az. 

m<>p.— Interopticus.     Not  in  tbe  cat. 

ins. — Insula. 

it. — Iter,  az. 

L.  ^.— Lobus  lateralis  (cerebelli). 

L.  ol. — Lobus  oifactorius. 

L.  imp. — Lobus  temporalis. 

Li  a;p._Lobulus  appendicularis  (cerebelliX 

LI.  /im2>  — Lobulus  hippocampi. 

Im.  aU). — Limes  alba. 

Im.  cin. — Limes  cinerea. 

lu. — Lura. 

ly. — Lyra,  az. 

mcs. — Medicommissura,  az. 
mcu. — Medicornu. 
mpd. — Medipedunculus,  az. 
msc. — Mesocoelia,  az. 
msen. — Mesencephalon,  az. 
mtc. — Metaccelia,  az. 
mten. — Metencephalon,  az. 
•  mtpx. — Metaplexus. 
?«^«?.— Metatela,  az. 
my. — Myelon,  az. 

N.  a6cZ.— Nervus  abducens  (vi). 

N.  ac. — Nervus  accessorius  (xi). 

iV^.  au. — Nervus  auditorius  (viii). 

N.  f — Nervus  facialis  (vii). 

N.  (/p^.— Nervus  glossopharyngeus  (ix). 

N.  ^(7.— Nervus  hypoglossus  (xii). 

N.  ocm.— Nervus  oculomotorius  (iii). 

N.  ol. — Nervus  oifactorius  (i). 

N.  op. — Nervus  opticus  (ii). 

N.  ^r.— Nervus  trochlearis  (iv). 

^.  trg. — Nervus  trigeminus  (v). 

N.  V. — Nervus  vagus  (x). 

oh. — Obex. 

olv. — Oliva. 

o^._ Opticus,  (Lobus). 


438 


A  NA  TOMICAL     TECHNOL  OGY. 


^.— Porta. 

pi. — Pia  (mater). 

pes. — Postcommissura,  az. 

pcu. — Postcornu.     Not  in  the  cat. 

pgn. — Postgeniculatum,  (Corpus). 

po,  ol, — Pero  (olfactorius). 

pohl. — Postoblongata,  az. 

pop. — Postopticus  (Lobus). 

pn. — Pons  (Varolii),  az. 

ppd. — Postpedunculus. 

ppf. — Postperforatus  (Locus),  az. 

ppx. — Portiplexus. 

pre. — Proccelia. 

^trcs. — Praecommissura,  02. 

prcu .  — P  raecornu. 

pren. — Prosencephalon,  az. 

prgn. — Prsegeniculatum. 

proU. — Praeoblongrata,  az. 

prpd. — Praepedunculus. 

prpf. — Praeperforatus  (Locus). 

prpx. — Proplexus. 

prsc. — Prosoccelia,  az. 

^r«pa?.— Prosoplexus,  az. 

ps.  ol. — Pes  (olfactorius). 

Pt.  d. — Portio  depressa  (praeperforati). 

Pt.  p. — Portio  prominens  (prgeperforati). 

pp. — Pyramis. 

psc.  — Pseudocoelia,  az. 

q. — Quadrans. 

r — Rima. 

R.  a. — Recessus  aulas,  az. 

R.  op. — Recessus  opticus. 


R.  prpn.  —Recessus  prsepoutilis,  az. 

Rg.  a. — Regio  aulica,  az. 

rhc. — Rhinoccelia. 

rhen. — Rhinencephalon,  az. 

I'm. — Rostrum,  az. 

rp. — Ripa, 

rst. — Restiforme,  (Corpus). 

Rx.  in. — Radix  intermedia. 

Rx.  I. — Radix  lateralis. 

Rx.  mt. — Radix  motoria, 

Rx.  ms. — Radix  mesalis. 

Rx.  sn. — Radix  sensoria. 

s. — Striatum,  (Corpus). 

SI.  h. — Sulcus  habenae. 

81.  ic.  I. — Sulcus  intercruralis  lateralis. 

8.  ic.  ms. — Sulcus  intercruralis  mesalis,  az. 

81.  li. — Sulcus  limitans. 

81.  trd. — Sulcus  triradiatus,  az. 

sp. — Splenium,  az. 

8pt.  lu. — Septum  lucid um  (cerebri),  az. 

str.  Irig. — Stria  longitudinalis  (callosi). 

t. — Terma,  az. 

Tbcl.  Rol. — Tuberculum  Rolandii. 

T.  cin. — Tuber  cinereum,  az. 

th. — Tlialamus. 

Tr.  op. — Tract  us  opticus.  • 

Tr.  prli. — Tractus  postrhinalis. 

Tr.  rh. — Tractus  rhinalis. 

tz. — Trapezium. 

1)1. — Velum  (interpositum),  az. 
'om. — Vermis,  az. 
m. — Valvula,  az. 


§  1129.  Most  of  the  above  names  are  those  in  common  use,  with  the  omission  of  super- 
fluous elements  like  corpus,  and  the  genitives  of  the  names  of  more  comprehensive  parts. 
Most  of  the  apparently  new  names  will  be  found  to  be  old  acquaintances  under  such  thin 
disguises  as  translation,  transposition,  abridgement,  and  the  substitation  of  prefixes  for 
qualifying  words.  In  a  few  cases  the  old  names  are  wholly  discarded  for  briefer  new 
ones  (e.  g.,  cimhia  for  Tractus  transversus  pedunculi).  Most  of  the  new  names,  however, 
refer  to  parts  apparently  unobserved  hitherto  (e.  g.,  crista,  carina,  delta),  or  to  parts  which 
— although  probably  observed — seem  not  to  have  been  regarded  as  needing  a  special 
designation  (e.  g.,  aula,  quadrans,  pero). 

For  the  names  of  the  segments,  coelisi,  telae  and  plexuses,  see  §  1063. 

So  much  of  each  name  as  immediately  follows  the  abbreviation  is  regarded  as  a  suflB- 
cient  designation  of  the  part  under  ordinary  circumstances ;  sometimes  it  may  be  necessary 
to  add  the  words  in  parenthesis. 

The  names  are  tabulated  according  to  segments  in  §  1138. 


FEATURES     OF    THE    MA3IMALIAN    BRAIN.  439 


THE  ENCEPHALIC   SEGMENTS  IN  THE  CAT. 


§  1130.  The  recognition  of  the  several  segments  is  less  easy  than 
with  the  frog  in  some  respects  on  account  of  certain  features  of  the 
mammalian  encephalon. 

§  1131.  Differences  betvreen  the  Brains  of  the  Cat  and  the 
Frog. — In  a  general  way  these  have  been  indicated  already  (§§  1055, 
1056) ;  they  may  he  more  definitely  stated  as  follows : — 

(1)  In  the  cat  the  coelise  are  irregular  in  form  and  relatively 
reduced  in  extent  (Fig.  113  ;  PL  II,  Fig.  4). 

(2)  The  parietes  are  relatively  thicker,  and  more  differentiated 
as  to  both  contour  and  structure  (Fig.  113 ;  PI.  II,  Fig.  4 ;  PI.  Ill, 
Fig.  13). 

(3)  With  several  segments  the  dorsal  portion  (roof)  is  much 
more  extensive  than  the  ventral  (floor),  (Fig.  117 ;  PI.  II,  Fig.  4). 

(4)  The  longitudinal  axis  of  the  entire  brain  presents  a  decided 
flexure,  the  convexity  of  which  is  dorsal  and  coincides  in  position 
nearly  with  the  mesencephalon  (Fig.  88). 

(5)  The  dorsal  portions  of  two  segments  (epencephalon  and  pros- 
encephalon) are  so  greatly  enlarged  as  to  cover  all  the  others  except- 
ing parts  of  the  metencephalon  and  rhinencephalon,  the  extremes 
of  the  series  (Fig.  88,  104,  117 ;  PI.  I,  Fig.  1,  3). 

(6)  In  addition  to  the  Amphibian  commissures  {chiasma,  postcommissura,  prceeommis- 
8ura),  there  are  in  the  cat's  brain  more  or  less  distinct  fibrous  fasciculi  constituting  other 
commissures — longitudinal  (Crura  cerebri,  Pi.  II,  Fig.  3,  Pi.  Ill,  Fig.  11 ;  Crura  olfactoria, 
PI.  II,  Fig.  3,  4  ;  postpedunculi,  praepedunculi) ;  transverse  (pons,  Fig.  117  ;  PI.  II,  Fig.  3, 
pn. ;  decussatio  pyramidum,  medipedunculi,  Commissura  fornicis,  PI.  IV,  Fig.  14,  cs.f.); 
and  oblique  (fornix,  Pi.  IV,  Fig.  14,/.). 

(7)  Between  the  apposed  surfaces  of  the  thalami  is  established  a  connection,  the  medi- 
commissura  (Fig.  122;  PI.  II.  Fig.  4,  mcs.),  which  occupies  a  large  portion  of  the  diaccelia. 

(8)  The  apposed  surfaces  of  the  hemispheres  are  connected  along  a  slightly  curved  line 
by  a  thick  band  of  fibers,  the  callosum  (Fig.  104,  115  ;  PI.  Ill,  Fig.  13,  PI.  IV,  Fig.  15,  d.), , 
the  largest  and  presumably  the  most  important  of  the  commissures. 

(9)  The  dorsal  aspect  of  the  mesencaphalon  presents  a  transverse  furrow,  distinguish- 
ing a  cephalic  pair  of  lobes,  the  optici  projjer,  from  a  caudal  pair,  the  postoptici  (Fig. 
114;  PI.  Ill,  Fig.  7);  hence  the  bigeminum  of  the  frog  becomes  the  quadrigeminum  of 
the  cat. 

(10)  The  lateral  aspect  of  the  diencephalon  presents  at  least  two  elevations,  postgenic- 
ulatum  and  praegeniculatum  (PI.  Ill,  Fig.  7,  9,  pgn.,  prgn.). 

(11)  Of  the  diaccelian  roof,  the  membranous  part  {diatela,  PI.  Til,  Fig.  10)  is  relatively 
more  extensive,  while  the  nervous  part  (postcommissura,  PI.  II,  Fig.  4,  pes.)  is  corre- 
spondingly diminished ;  concomitantly  the  conarium  is  attached  near  the  caudal  end  of 
the  diencephalon  and  is  retroverted  so  as  to  rest  upon  the  mesencephalon. 


440 


ANA  TO  MIC  A  L    TECHNO  LOGY. 


(12)  Each  lateral  half  of  the  rhinencephalon  consists  of  a  Lobus  olfactorius  connected 
with  the  prosencephalon  by  a  distinct  Crus  olfactorium  (PI.  II,  Fig.  3,  4,  Cr.  ol.). 

(13)  Each  procoelia  may  be  subdivided,  somewhat,  vaguely,  into  a  central  cella  media 
(PI.  IV,  Fig.  15,  eel.  m.),  and  two  curved  prolongations,  the  praecornu  (PI.  II,  Fig.  121, 
PI.  IV,  Fig.  15,  IQ.prcu.),  and  the  medicornu  (PI.  IV,  Fig.  15,  17,  18,  mcu.) 

(14)  Into  each  cornu  projects  a  decided  eminence.  That  of  the  praecornu  is  the  stria- 
tum (PI.  IV,  Fig.  15,  16,  s.),  a  thickening  of  the  parietes.  That  of  the  medicornu  is  the 
hypocampa  (PI.  IV,  Fig.  15,  16,  Jimp.),  which  is  chiefly  an  involution  or  folding  of  the 
parietes  (Fig.  121). 

(15)  In  addition  to  the  atrophied  portions  of  the  ccelian  parietes  noted  in  the  frog,  the 
proper  nervous  substance  of  the  hemisphere  is  abrogated  along  a  line  from  the  porta  to 
near  the  tip  of  the  medicornu,  constituting  the  rima  or  "  fissure  of  Bicliat"  (Fig.  121 ;  PI. 
IV,  Fig.  14,  17,  B.).    Along  this  line  enters  the  larger  portion  of  the  proplexus. 

(16)  As  in  Menobranchus,  there  are  metaplexus,  diaplexus  and  proplexus,  the  latter 
two  being  continuous  through  the  intermediation  of  the  auliplexus  and  portiplexus. 

(17)  The  surface  of  the  cerebellum  is  convoluted,  presenting  numerous  thin  folds 
{laminm)  with  intervening  fissures  (Fig.  104,  117  ;  PI.  I,  Fig.  1,  2). 

(18)  The  surface  of  the  hemispheres  is  also  convoluted,  presenting  a  limited  number  of 
fissures  arranged  according  to  a  somewhat  definite  pattern  (Fig.  124,  125  ;  PI.  I,  Fig.  1,  2). 
Most  of  the  fissures  involve  only  a  certain  depth  of  the  mass,  but  the  F.  hypocampce,  "  hip- 
pocampal  fissure,"  represents  an  involution  of  the  entire  thickness  of  the  parietes  (Fig. 
121,  125  ;  PI.  IV,  Fig.  15,  17,  F.  hmp.). 

(19)  With  the  cerebellum  and  hemispheres,  most  of  the  cinerea  is  located  near  or  at 
the  surface,  constituting  a  cortex  (PI.  II,  Fig.  4,  PI.  IV,  Fig.  14,  15).  The  extent  of  the 
cortex  is  of  course  increased  by  the  convolutions. 


Fig.  113. — Ventral  exposure  of  the  cceliae ; 
preparation  No.  458,  Museum  of  Cornell  Uni- 
versity.    Compare  with  Fig.  110. 

Objects. — To  show  (A)  the  general  succession 
of  the  cceliae ;  (B)  the  relations  of  the  portas  to 
the  aula  and  procoeliae ;  (C)  the  thickness  of  the 
parietes  and  concomitant  reduction  of  the  cceliae  ; 
(D)  the  undulations  of  the  ccelian  roofs. 

Preparation. — From  the  ventral  aspect  of  a 
15  cs^^^BP^      npi       r^k^    y  ^^^^  hardened  brain  successive   slices  were  re- 

ft i  ^^mepenMa       \^Y^  moved  with  the  large  scalpel  until  the  portce  and 

Canalis  centralis  were  ex:posed.  With  the  Char- 
riere  scalpel  there  were  excavated  successively  so 
much  of  the  various  segments  as  to  expose  the 
entire  series  of  cceliae,  excepting  the  rhinocceliae, 
the  rhinencephalon  having  been  removed. 

On  the  right  (left  of  the  figure)  the  convexity 
of  the  striatvm  was  cut  off.     On  the  other  side 
enough  more  of  the  hemisphere  and  thalamus 
was  removed  to  expose  the  proplexus  and  thus 
throw  the  praecornu  into  direct  communication  with  the  medicornu. 

Explanation. — Most  of  the  names  are  written  in  full,  and  the  parts  mentioned  are 
described  elsewhere. 

Cii.  ce. — Canalis  centralis  myelonis. 


^ercbeLLint 


etacQclioj 


ViyeCo 

Fig.  113. — Ventral  Exposure  of 
the  cceli.^  ;   x  1. 


DORSAL    ASPECT    OF    THE    MESENCEPHALON: 


441 


keThiSpha^raC 


Dien.,  ei^n.,  mesen.,  meten.  are  abbreviations  of  diencephalon,  etc.  So  much  of  the 
prepaT-ation  as  is  not  included  therein  belongs  to  the  prosencephalon. 

Pgn. — Postgeniculatum.     Th. — Thalamus. 

The  sides  of  all  the  cceliae  are  beveled  olt  so  as  to  expose  their  roofs  more  clearly.  The 
Avidest  portion  is  the  metacoelia,  whose  proper  roof  (metatela)  is  so  thin  that  the  laminae 
of  the  overhanging  cerebellum  show  through  it . 

The  epiccElia  presents  two  very  different  portions — a  caudal,  which  is  short  but  wide 
and  high,  reaching  up  into  the  cerebellum  (PI.  II,  Fig.  4),  and  a  cephalic,  longer  but  nar- 
rower and  lower,  excepting  at  its  cephalic  end,  where  its  roof,  the  valvula,  rises  to  join 
the  postoptici. 

The  succeeding  contracted  portion  represents  the  mesocoelia  ;  the  next  mesal  cavity 
is  the  diaccelia,  the  roof  of  which  presents  the  two  parallel  diaplexuses,  diverging  in  the 
aula  to  connect  through  the  portae  with  the  proplexuses. 

On  the  right  (left  of  the  figure)  the  crescentic  line  representing  the  transection  of  the 
medicornu  should  reach  the  end  of  the  line  indicating  the  boundary  between  the  hemi- 
sphere and  the  postgeniculatum;  see  Fig.  121. 

The  membranes  and  the  relative  areas  of  alba  and  cinerea  are  not  shown. 

Fig.  114. — Dorsal  aspect  of  the  mesencephalon, 
exposed  by  the  separation  of  the  cerebellum  and 
hemispheres ;  from  Prep.  No.  390,  M.  C.  U. 

Objects. — To  expose  (A)  the  dorsal  aspect  of  the 
mesencephalon,  the  cephalic  aspect  of  the  cerebel- 
lum and  the  caudal  aspect  of  the  hemispheres  ;  (B) 
the  origin  of  the  NN.  trochleares  from  the  cephalic 
part  of  the  valvula  {'cv.) ;  (C)  the  caudal  position  and 
retroversion  of  the  conarium. 

Preparation. — The  fresh  brain  was  carefully  held 
and  the  caudal  portions  of  the  hemispheres  gently 
pushed  cephalad,  the  attachments  to  the  mesencepha- 
lon being  divided  with  the  tracer,  until  the  conarium 
was  exposed ;  then  the  cerebellum  was  in  like  man- 
ner tilted  caudad,  care  being  had  not  to  tear  the 
delicate  valvula. 

By  the  above  operations  the  natural  encephalic 
flexure  was  so  exaggerated  as  to  bring  the  ventral 
aspects  of  the  crura  olfactoria  and  the  metencephalon 
into  contact.     The  brain  was  secured  in  this  condition 

upon  a  bed  of  wet  cotton  by  pushing  cotton  against  it,  and  covered  with  95  per  cent, 
alcohol. 

Explanation. — The  names  are  written  in  full,  excepting  m.  for  valvula.  The  furrow 
between  the  optici  is  not  sufficiently  distinct,  and  the  word  postoptici  obacures  the  fact 
that  the  elevations  so  named  are  separated  by  a  somewhat  wide  and  flat  valley  rather  than 
by  a  narrow  depression.. 

In  the  preparation,  the  infundibuliform  mesoccelian  orifice  is  visible  through  the  trans- 
parent valvuia.     Compare  PI.  III.  Fig.  7. 

Fig.  115. — The  callosum  after  removal  of  the  dorsal  portions  of  the  cerebellum  and 
hemispheres  ;  from  Prep.  No.  540,  M.  C.  U. 

Objects. — To  show  (A)  the  fact  of  the  connection  of  the  hemispheres  by  the  callosum ; 


Fig.  114. — Dorsal  Aspect  of 
THE  Mesencephalon,  with 
SOME  Adjacent  Parts;   x  1. 


442 


ANATOMICAL    TECHNOLOGY. 


lofxi  olj- 


(B)  the  cephalo-caudal  extent  of  the  latter;  (C)  the  manner  of  cleavage  of  the  hemis 
spheres ;  (D)  the  irregular  lamination  of  the  cerebellum. 

Preparation. — The  hemispheres  and  Ldbi  olfactorii  of  a  hardened  brain  were  sliced  to 
near  the  level  of  the  callosum  and  in  a  plane  coinciding  with  the  larger  part  of  its  course. 

The  slight  portions  overhanging  the  borders  of  the 
callosum  so  as  to  constitute  the  FF.  callosales  (Fig.  116, 
122;  PI.  Ill,  Fig,  13)  were  then  pushed  dorso  laterad 
with  the  tracer ;  the  torn  surfaces  so  left  are  repre- 
sented by  the  striated  areas.  On  the  right,  a  part  of 
the  hemisphere  was  torn  off  so  as  to  indicate  the  wave- 
like arrangement  of  the  fasciculi. 

An  oblique  section  was  then  made  from  opposite 
the  splenium  through  the  caudal  portion  of  the  hemi- 
spheres and  the  cerebellum,  so  as  to  expose  the  post- 
optici. 

Explanation. — The  name  is  written  lengthwise  of 
the  callosum  ;  perhaps  the  line  at  each  side  represents 
a  stria  longitudinalis.  The  curvature  ventrad  at  the 
genu  and  splenium  is  better  shown  in  section  (Fig. 
116;  PI.  II,  Fig.  14).  The  postoptici  do  not  appear 
distinctly,  and  no  attempt  was  made  to  indicate  the 
areas  of  cerebral  alba  and  cinerea,  or  of  the  pes,  pero 
or  ccelia  in  the  rhinencephalon. 

§  1132.    Preliminary  Examination  of  the  Basis 

Encephali.— As  seen  in   Fig.    116,   118,  and  PI.    II, 

Fig.  3,  the  base  of  the  brain  presents  numerous  parts 

distinguished  by  their  elevation,   their    subdivision, 

their  color  or  the  direction  of  their  fibers.     Including  the  twelve  cranial  nerves,  about 

fifty  different  parts,  more  or  less  comprehensive,  are  named  upon  Fig,  116. 

The  cranial  nerves  are  treated  of  in  the  next  chapter.  Of  the  remaining  parts,  the 
beginner  is  advised  to  study  first  only  those  which  have  been  observed  in  the  Amphibian 
brain,  or  which  serve  either  as  topographical  landmarks  or  as  aids  in  recognizing  the  limits 
of  the  encephalic  segments.  Later,  it  will  be  desirable  to  identify  each  feature  by  the  aid 
of  the  figures  (Fig.  118  ,  PI.  II,  Fig.  3  ;  PI.  Ill,  Fig.  11)  and  the  detailed  descriptions. 
Fig.  116. — Diagram  of  the  base  of  the  brain,  including  the  nerve  roots. 
Explanation. — The  names  are  written  in  full.  As  suggested  above,  the  following 
parts  are  to  be  noted  first : — 

Myelon,  expanding  into  the  metencephalon. 
Cerebellum,  greatly  enlarged  and  convoluted. 
Hemisphserae,  still  more  enlarged  and  likewise  convoluted. 
Lobi  olfactorii,  elongated  and  in  apposition,  but  not  organically  united. 
Chiasma,  Tuber  cinereum,  infundibulum,  hypophysis,  Crura  cerebri  (one  of  which 
is  designated  on  Fig.  116  by  the  word  cmn)  and  pons. 

Of  the  parts  just  named,  all  but  the  last  have  been  noted  upon  the  mesal  aspect  of  the 
Amphibian  brain,  and  are  mentioned  in  the  Table  (§  1069). 

The  pons  is  a  wide  and  thick  band  of  transverse  fibers  connecting  the  lateral  lobes  of 
the  cerebellum  across  the  ventrimeson.     It  is  likewise  a  prominent  landmark,  serving, 
with  the  chiasma,  to  divide  the  entire  basis  encephali  conveniently  into  three  general  \ 
regions — caudal,  Area  postpontilis  ;  ceplialic,  Area  praechiasmatica ;  and  intermediate,  \ 
Area  cruralis.  ; 


Fig.  115. — Dorsal  Aspect  of 
THE  Callosum  after  Par- 
tial Removal  of  the 
Hemispheres  ;   x  1. 


EXAMINATION    OF    THE    BASIS    ENCEPHALI. 


443 


I 


^i&rvceaU»» 


Fig.  116. — Diagram  of  the  Basis  Encephali  ;   x3. 

It  is  to  be  observed  that,  notwithstanding  the  preponderance  of  the  cerebellum  and  the 
lisphereg,  all  the  encephalic  segments  appear  upon  the  ventral  aspect,  most  distinctly 
at  and  near  the  meson.  On  the  left  (right  of  the  figure)  the  names  of  the  prosencephalon 
are  written  along  its  expanded  dorsal  portion,  but  upon  the  ventrimeson  it  may  be 


444  ANATOMICAL    TECHNOLOGY. 

regarded  as  extending  only  from  the  middle  of  tlie  cbiasma  to  the  diamond-shaped  area 
just  caudad  of  the  rhinencephalic  Radices  mesnles. 

The  extent  of  the  metencephalon  coincides  nearly  with  that  of  the  pyramis. 

§  1133.  Hemisection  of  the  Brain. — The  encephalic  segments  are  more  easily  recog- 
nized and  examined  upon  a  hemiencephalon  than  upon  the  entire  organ  because  (1)  all  the 
segments  and  most  of  the  coelise  are  then  exposed  ;  (2)  the  parts  can  be  more  readily  bent 
upon  each  other  or  dissected  apart. 

Instruments  and  Materials. — A  brain,  symmetrical  and  well-liar dened  ;  distorted  speci- 
mens may  serve  for  dissections,  but  for  the  hemisection  select  the  most  perfect.  Kazor  or 
large  scalpel,  with  very  keen,  smooth  edge  ;  if  the  scalpel  is  used,  it  should  be  especially 
sharp  at  the  heel,  which  is  usually  neglected.  A  small  dish  or  vial  of  alcohol,  in  which 
the  knife  may  be  dipped.  A  piece  of  sheet  cork,  or  of  soft  wood  free  from  knots,  at  least 
6x4  cm.,  and  preferably  16  x 8.  Remove  from  the  brain  any  pins  which  may  cross  the 
meson. 

§  1134.  Upon  a  preparation  or  figure  (Fig.  115,  116 ;  PL  II, 
Fig.  4),  note  the  position  of  the  callosum  and  the  angle  which  it 
forms  with  the  dorsal  and  ventral  surfaces  of  the  brain. 

Place  the  brain  upon  its  basis,  with  its  long  axis  coincident  with 
the  length  of  the  cork  or  the  grain  of  the  wood,  and  the  cephalic 
end  of  the  brain  to  the  left. 

Dip  the  scalpel  in  alcohol,  and  grasp  it  bow-fashion.  Introduc(^ 
the  tip  of  the  blade  between  the  hemispheres  at  their  highest  part, 
and  gently  push  it  ventro-cephalad  until  the  point  reaches  the  cork 
a  little  in  advance  of  the  Lobi  olfactorii,  and  the  back  of  the  blade — 
if  a  scalpel  is  used— is  about  on  a  level  with  the  dorsal  margins  of 
the  hemispheres.  The  blade  then  forms  an  angle  of  about  30 
degrees  with  the  cork,  and  its  heel  is  a  little  cephalad  of  the  cere- 
bellum. 

Grasp  the  brain  gently  but  firmly  as  follows :— The  pollex 
should  be  on  the  left,  against  the  lateral  surface  of  the  cerebellum 
and  the  caudal  part  of  the  hemisphere  ;  on  the  right  the  tips  of  the 
index,  medius  and  annularis  press  respectively  upon  the  lateral 
aspect  of  the  cerebellum  and  the  temporal  and  frontal  regions  of  the 
hemispheres.  The  minimus  may  be  raised  out  of  the  way.  The 
pressure  upon  the  two  sides  of  the  brain  must  be  equal  and  uniform. 

Draw  the  scalpel  slowly  caudad,  keeping  the  convexity  near  the 
tip  constantly  upon  tlie  cork,  and  the  entire  instrument  at  the  same 
angle  until  it  emerges  through  the  cerebellum  and  the  medulla. 

^At  the  beginning  of  the  hemisection,  the  edge  of  the  scalpel 
was  firmly  held  by  the  closely  approximated  hemispheres,  and 
its  edge  rested  on  the  callosum,  so  that  the  latter  was  probably 
divided  accurately  on  the  meson.     But  a  very  slight  initial  deflec- 


444rt 


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HEMISECTION    OF    THE    BRAIN.  445 

tion  may  have  brought  the  blade  out  1-2  mm.  laterad  of  the  ventri- 
meson. 

Ascertain  the  extent  of  the  departure  by  apposing  the  two  lialves 
of  the  brain  and  noting  the  position  of  the  cut  with  respect  to  the 
ventri meson.  If  the  cut  and  the  meson  coincide,  the  surfaces  of  the 
two  sides  of  the  brain  will  be  practically  identical ;  but  accoi^ing 
to  the  degree  of  the  separation  there  will  be  found  a  difference 
which  is  sometimes  so  great  as  to  be  puzzling  to  the  beginner, 
especially  since  in  these  cases  neither  surface  resembles  that  shown 
in  the  figure. 

After  becoming  somewhat  familiar  with  the  organ,  it  may  be 
well  to  make  purposely  a  hemisection  about  1  mm.  laterad  of  the 
meson,  so  that  the  commissures  and  other  mesal  structures  may  be 
dissected  out  in  relief ;  but  at  the  outset  it  is  better  to  secure  a 
view  of  the  mesal  surface  itself. 

Select  that  half  of  the  brain  to  which  part  of  the  other  half  is 
attached,  and  hold  it  with  the  meson  up  and  the  base  toward  you  ; 
grasp  the  large  scalpel  bow-fashion,  and  apply  the  heel  at  the  ven- 
trimeson,  upon  the  chiasma  if  it  be  the  right  half,  or  at  the  ventri- 
mesal  {"  anterior  median  ")  fissure  of  the  metencephalon  if  the  left ; 
cut  away  from  you  with  a  long  steady  sweep,  taking  care  not  to  cut 
upon  the  other  side  of  the  meson.  Certain  parts  of  the  surface  may 
require  subsequent  special  treatment  in  order  that  the  surfaces  may 
be  fairly  exposed. 

§  1135.  Aside  from  detailed  comparison  of  the  surface  with  the 
figures,  the  best  test  of  the  mesal  surface  is  the  exposure  of  the 
series  of  mesal  coeliee,  extending,  as  in  the  Amphibian  brain  (Fig. 
Ill),  in  uninterrupted  continuity  from  the  ventro-caudal  angle  of 
the  cerebellum  to  a  point  dorsad  of  the  chiasma.  Just  ventrad  of 
the  cerebellum  the  lateral  extent  of  the  cavity,  epicoelia,  is  con- 
siderable, but  at  other  points  it  is  no  more  than  1-2  mm.,  so  as  to 
appear  on  the  mesal  surface  like  a  shallow  depression.  The  most 
obscure  portion  of  the  cavity  is  the  cephalic  part  of  the  epicoelia, 
where  the  lateral  extent  is  considerable,  while  its  vertical  diameter 
is  very  slight,  and  the  roof,  valvula,  is  quite  thin. 


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^^|ced  Hue  from  the  woid/«9rwia;,  the  narrow,  white  area  represents  the  cut  surface  of  the  fornix.  The 
narrow,  light  area  (2)  extending  dorso-caudad  from  the  dotted  line  represents  the  natural  margin  of  a  ridge 
which,  had  the  callosum  been  developed,  would  presumably  have  extended  across  the  meson  and  united 
with  its  platetrope  to  form  the  horizontal  portion  of  the  fornix  and  the  fomieon.missure,  continuous  caudad, 
through  the  splonium,  with  the  callosum.  In  accordance  with  changes  elsewhere  indicated  cs.  h.  represents 
the  supracommissnre,  and  opticus  should  be  preopticus  ;  pes.  indicates  poetcommissure  ;  i,  the  ragged  line 
left  by  tearing  off  the  valvula.  The  brain  was  removed  and  hemisected  by  a  student  before  the  peculiarities 
were  observed  and  Is  somewhat  distorted  ;  the  olfactory  lobe  (L.  ol.)  was  partly  lost,  and  the  hypophysis 
torn  off.  The  medicommissure  and  precommissnre  are  larger  than  usual.  For  fuller  description  and  dis- 
cussion see  a  paper  (/3)  by  the  senior  author.    The  specimen  is  381  M.  C.  U. 


450  ANATOMICAL    TECHNOLOGY. 

§  1139.  Examination  of  the  Encephalic  Segments. — Instru- 
ments and  Materials. — A  hemienceplialon,  well  hardened  ;  the 
condition  of  its  lateral  aspect  may  l>e  disregarded.  Large  and 
Charriere  scalpels,  both  very  sharp.  Syringotome  or  tracer.  Fine 
scissors.  Blowpipe.  Coarse  and  line  forceps.  Beaded  bristles. 
Small  dish  or  wide-mouthed  vial  of  alcohol,  into  which  the  brain 
and  the  scalpels  may  be  dipped. 

In  dissection  of  the  brain,  the  scalpels  should  be  "eery  sharp y 
and  dipped  in  alcohol  just  before  each  incision. 

Hhinencephalon  (examined  first  on  account  of  its  liability  to 
injury  during  the  study  of  the  other  parts). — Yentriduct  the  Lobus 
olfactorius  so  as  to  expose  the  dorsal  aspect  of  the  Crus  ol. ;  also 
the  Fissura  ol.  (PI.  Ill,  Pig.  5,  F.  ol.)  on  the  ventro-cephalic  sur- 
face of  the  hemisphere  in  which  rests  the  dorsal  border  of  the  cms. 

At  the  junction  of  the  crus  with  the  lobus,  note  the  slight  promi- 
nence of  the  softer  ectal  layer,  the  pero,  from  which  directly  arise 
the  olfactory  nerves  (PI.  II,  Pig.  3,  NJSf.  ol.).  Remove  the  pero 
with  the  forceps  and  tracer,  and  note  that  there  remains  a  thin 
smooth  lamina,  the  pes  ol.,  which  is  partly  fibrous  and  forms  the 
immediate  continuation  of  the  crus. 

The  rhinocodia  will  be  more  easily  seen  upon  the  dissection  of 
another  specimen. 

§  1140.  Metencephalon.—Of  this  segment,  one  part,  the  pyra- 
mis,  has  been  noted.  Laterad  of  the  cephalic  part  of  the  pyramis 
is  a  quadrangular  area,  the  trapezium  (PI.  II,  Pig.  3,  tz.) ;  laterad 
of  its  caudal  and  longer  portion  are  two  elevations,  here  called  from 
their  outlines.  Area  elliptica  and  Area  ovalis. 

The  dorsal  aspect  of  the  metencephalon  is  overhung  by  the  cere- 
bellum. Tilt  the  latter  cautiously  latero-cephalad,  using  the  tracer 
to  disengage  from  its  ventral  aspect  the  delicate  metatela,  the  roof 
of  the  metacoelia  (PL  III,  Pig.  12,  mttl.).  Even  if,  in  so  doing,  the 
metatela  is  torn  from  its  connection  with  the  border  of  the  metaccelia 
(so  as  to  produce  a  ''Foramen  of  Magendie,"  §  1082),  it  may  usu- 
ally be  traced  continuous  with  the  ventral  surface  of  the  cerebellum 
just  caudad  of  the  epiccelia. 

Now  tilt  the  cerebellum  meso-cephalad  and  note  the  mass  of 
membrane  and  blood-vessels  forming  the  metaplexus  lateralis 
(PL  II,  Fig.  4 ;  PL  III,  Pig.  12,  mtpx.). 

Upon  removal  of  the  metatela  and  metaplexus,  there  will  be 


EXAMINATION    OF    THE    ENCEPHALIC    SEGMENTS.  451 

seen  a  transverse  band  (Tractus  auditorius)  passing  from  the  Emi- 
nentia  auditoria  across  the  wall  of  the  metacoelia. 

§  1141.  Epencejphalon. — Tilt  the  cerebellum  caudo-laterad,  so 
as  to  exj)ose  the  limits  of  the  epiccelia.  Note  the  distinction  be- 
tween its  caudal  portion,  which  extends  dorsad  Into  the  cerebellum, 
and  the  rest,  which  has  for  its  roof  only  the  thin  valvula.  Separate 
the  valvula  from  the  cerebellum,  noting  the  continuity  of  the  two  at 
the  caudal  end  of  the  former. 

With  the  forceps  and  tracer  tear  and  push  off  the  lateral  part  of 
the  cerebellum  so  as  to  expose  the  medipedunculus,  the  continua- 
tion of  the  pons  into  it.  In  like  manner,  remove  the  caudal  part  of 
the  cerebellum,  and  note  a  less  distinct  fasciculus,  the  postpediin- 
culus,  passing  from  the  Tractus  lateralis  of  the  metencephalon  to  the 
cerebellum  just  mesad  of  the  medipedunculus.  The  praapeduncu- 
lus  is  exposed  by  the  removal  of  the  cephalic  part  of  the  cerebellum  ; 
it  forms  the  lateral  wall  of  the  cephalic  part  of  the  epiccelia^  and  is 
continuous  with  the  base  of  the  postopticus. 

Push  the  tracer  entad  of  the  medipedunculus,  and  then  divide  it 
with  the  scissors.  Grasp  the  ventral  piece  and  tear  off  the  pons  as 
far  as  the  meson.  JS'ote  that  the  pons  concealed  the  continuity  of 
the  pyramls  with  the  Cms  cerebri. 

§  1142.  Mesencephalon. — Note  the  slenderness  of  the  mesocce- 
lia,  whence  the  names  iter  and  aquceductus  SylviL 

Ventriduct  the  meten.  and  epen.  so  as  to  leave  a  space  between 
them  and  the  hemisphere.  Remove  the  caudal  end  of  the  latter  by 
a  dorso-ventral  incision  corresponding  with  the  convexity  of  the 
splenium.  On  the  cut  surfaces,  note  the  darker  color  of  the  ectal 
cinerea.,  the  cortex,  as  compared  with  the  ental  alba.  There  will 
be  exposed  a  cavity,  the  medicornu,  and  a  rounded  elevation,  the 
hypocampa.    These  may  be  disregarded  for  the  present. 

With  the  pollex  tear  away  the  Lobulus  hypocampge  (PI.  I, 
Fig.  3,  LI.  limp.)  and  so  much  of  the  hemisphere  as  readily  comes 
off  vrith  it ;  then  cut  off  as  much  more  as  may  be  necessary  to  ex- 
pose the  Tractus  opticus  {Tr.  op). 

The  parts  thus  exposed  will  be  found  covered  by  pia^  which 
forms  a  distinct  fold  in  the  F.  hypocampcB  (Fig-.  121). 

This  covering  of  the  mesencephalon  and  part  of  the  diencephaloTi 
is  called  the  velum  {interjyositum).  Remove  it  with  the  forceps, 
beginning  at  the  postopticus.     Note  the  slender  N.  trocJilearis 


452  ANATOMICAL     TECHNOLOGY. 

passing  laterad  and  then  ventrad  just  caudad  of  the  postopticus 
from  its  ectal  origin  on  the  cephalic  part  of  the  valvula. 

Observe  the  contrast  in  form  and  position  of  the  opticus  and 
postopticus.  The  latter  is  farther  from  the  meson  and  more  sharply 
defined ;  the  opticus  presents  a  more  gradual  slope  to  the  meson. 
Extending  laterad  from  the  lateral  slope  of  the  opticus,  note  the 
cimbia,  the  ventral  part  of  which  crosses  the  crus  in  the  Area  cru- 
ralis  (Fig.  116,  118 ;  PL  II,  Fig.  3,  and  PL  III,  Fig.  11,  cmh.).  The 
cimbia  seems  to  indicate  the  boundary  between  the  mesencephalic 
and  diencephalic  portions  of  the  crus. 

§  1143.  BiencepTialori. — Note  the  great  dorso-ventral  extent  of 
the  diacoelia,  the  presence  of  the  medicommissura  (mcs.)  in  its  dor- 
sal part,  and  the  absence  of  any  distinct  boundary  between  the 
diaccelia  and  the  aula. 

The  thalami  constitute  the  lateral  parietes  of  the  diacoelia,  and 
its  ventral  and  cephalic  boundaries  are  sufficiently  obvious,  but  the 
dorsal  require  specification. 

The  most  caudal  part  of  the  roof  is  formed  by  the  postcommis- 
sura  (pes.),  which  intervenes  between  the  opticus  and  the  cona- 
rium  (en.). 

Between  the  medicommissure  and  the  fornix  the  most  prominent 
part,  especially  with  an  injected  preparation,  is  a  longitudinal 
plexus,  the  diaplexus. 

Lift  the  diaplexus  with  the  tracer  at  about  the  middle  of  its 
length  and  note  that  it  is  attached  throughout  by  one  edge,  and 
that  it  partly  covers  a  ridge  upon  the  mesal  aspect  of  the  thalamus. 
This,  the  habena  (h.\  is  widest  near  its  caudal  end,  which  joins  its 
plate  trope  by  a  slender  band,  the  Commissura  habenarum  {Cs.  7i.), 
just  dorsad  of  the  conarium. 

The  habena  becomes  narrower  and  less  prominent  cephalad  and 
disappears  at  the  cephalic  convexity  of  the  thalamus,  corresponding 
with  the  dorsal  limit  of  the  porta. 

Grasp  the  diaplexus  with  the  fine  forceps  and  gently  pull  upon  it. 
Note  that  it  readily  separates  from  the  other  parts  excepting  at  the 
ends.  The  ends  are  connected  with  somewhat  large  vessels,  but  the 
precise  arrangement  is  not  clear  to  us.  Recall  the  relations  of  the 
diaplexus  in  Menobranchus  (§  1097),  where  it  is  free  excepting  at 
the  cephalic  end. 

Eemove  the  diaplexus  by  carefully  cutting  the  caudal  and  ce- 
phalic connections,  and  note  that  it  was  attached  to  the  ventral  or 


EXAMIXATION    OF    THE    ENCEPHALIC    SEGMENTS.  453 

ental  aspect  of  a  delicate  membranous  roof  of  the  diacoelia,  the 
diatela  (Fig.  122). 

By  slightly  pushing  the  hemisphere  away  from  the  thalamus, 
it  will  be  seen  that  the  diatela  springs  from  the  dorsal  margin  of  the 
habena,  along  a  slight  furrow,  the  Sulcus  habenae  {SI.  h.),  and 
curves  dorso-mesad  to  meet  its  other  half  from  the  opposite  side. 

§  1144.  On  the  lateral  aspect,  between  the  cimbia  and  the  tractus 
opticus,  note  a  decided  elevation,  the  postgeniculatum  (Fig.  18 ; 
PI.  Ill,  Fig.  7,  9,  pgn.).  Ventrad  of  it  is  a  ridge  of  the  crus,  partly 
embracing  a  depressed  area,  the  quadrans  (Fig.  18 ;  PI.  Ill,  Fig. 
11,  q.). 

Ventriduct  the  parts  still  more,  and  trace  the  tractus  opticus 
into  an  expanded  elevation  just  cephalad  of  the  postgeniculatum. 
This,  the  praegeniculatum  (PL  III,  Fig.  7,  9,  prc/n.),  is  practically 
continuous  with  the  thalamus,  the  principal  part  of  the  diencepha- 
lon,  which  has  been  seen  above  as  the  lateral  wall  of  the  diacoelia. 
Note  the  absence  of  any  distinct  caudal  protrusion  of  the  thalamus, 
such  as  forms  the  human  pulmnar.  At  the  meson,  in  the  depres- 
sion between  the  tlialamus  and  the  opticus,  note  the  half  of  the 
conarium,  more  or  less  enveloped  by  the  velum,  and  inclined  cau- 
dad  from  its  attachment  so  as  to  rest  upon  the  opticus. 

By  an  incision  beginning  just  dorsad  of  the  callosum  and  ex- 
tending laterad  and  very  slightly  dorsad,  remove  the  dorsal  portion 
of  the  hemisphere.  The  features  of  the  cut  surface. may  be  disre- 
garded here  ;  the  object  is  to  permit  what  is  left  to  be  raised  more 
easily.  On  lifting  this  portion,  note  that  its  ventral  surface  presents 
slight  fissures  and  striae,  trending  latero-caudad.  This  is  the  fornix 
(PL  ly,  Fig.  14,/.),  including  the  lyra  (ly.\  the  limits  of  which  have 
not  been  determined.  Note  that,  for  a  short  distance  from  the  sple- 
nium,  the  plane  of  the  fornix  coincides  with  that  of  the  callosum, 
but  that  it  curves  ventrad  so  as  to  become  nearly  vertical  at  its 
cephalic  end.  The  general  shape  of  the  fornix  is  triangular ;  its 
larger  portion  is  the  body,  and  the  narrower  cephalic  end  is  the  col- 
umna.  The  band  which  forms  its  lateral  border  is  the  fimbria, 
which,  as  will  be  seen  later,  is  continued  nearly  to  the  tip  of  the 
LI.  JiypocampcB. 

Between  the  fornix  and  the  diencephalon  is  a  fold  of  pia,  the 
velum.  When  freed  from  the  velum,  note  the  difference  between 
the  dorsal  surface  of  the  thalamus  and  the  mesal  surface  already 


454  ANATOMICAL    TECHNOLOGY. 

exaaiined  (§  1043) ;  the  latter  is  entocoelian  and  covered  by  endyma  ; 
the  former  is  wholly  ectocoelian  (Fig.  122). 

But,  along  the  free  border  of  the  fimbria,  the  velum,  or  vessels 
thereof,  passes  into  the  procoelia,  covered  by  the  endyma^  whose 
attachment  may  be  noted  along  the  entire  length  of  the  fimbria  (Fig. 
121).  This  solution  of  the  continuity  of  the  nervous  tissue  along 
the  border  of  the  fimbria  is  the  rima  (PL  lY,  Fig.  14,  r.),  and  the 
intruded  border  of  the  velum  is  the  proplexus  (PL  lY,  Fig.  15,  ppx.). 

§  1145.  Aula  and  Porta. — Cut  off  the  larger  part  of  the  fornix 
with  the  corresponding  portion  of  tlie  callosum,  gently  push  the 
fornix  from  the  thalamus,  and  note  that,  at  about  the  junction  of 
the  body  with  the  columna,  the  adhesion  of  the  velum  to  both  for- 
nix and  thalamus  ceases  suddenly,  and  that  the  surfaces  of  both, 
ventrad  of  the  adhesions,  are  covered  by  the  smooth  endyma  which 
is  characteristic  of  the  coelian  cavity. 

So  much  of  the  interval  between  the  fornix  and  thalamus  as  lies 
ventrad  of  the  lines  of  adhesion  is  the  porta.  Its  ventral  limit  is 
formed  by  the  continuity  of  the  two  masses  (Fig.  123). 

The  adhesions  coincide  with  the  lines  of  reflection  upon  the  in- 
truded velum  of  the  endyma  from  the  columna  and  thalamus.  The 
slight  space  mesad  of  the  porta  is  the  aula,  and  the  irregular  cavity 
laterad  of  the  porta  is  the  procoelia,  which  will  be  examined  later. 

So  much  of  the  brain  as  has  not  been  specified  appertains  to  the 
prosencephalon. 

§  1146.  Demonstration  of  the  ProccBlia,  Rhinocoelia  and  Porta 

("Lateral  and  olfactory  ventricles  and  Foramen  of  Monro"). — The 
proccelia  and  porta  have  been  incidentally  exposed  during  the  ex- 
amination of  the  encephalic  segments.  The  following  directions 
deal  particularly  with  their  parietes  and  with  the  continuity  of  the 
proccelia  with  the  rhinoccelia. 

Instruments  and  Materials. — The  same  as  for  the  examination 
of  the  segments  (§  1139).    The  syringotome  is  preferable  to  the  tracer 

For  the  most  satisfactory  study  of  the  ccelise  and  the  plexuse 
the  arteries  should  have  been  injected  with  gelatin  (§  1126)  and  alco 
hoi  throw^n  into  the  Foramen  infundihull  (§  1124).  The  following 
figures  should  be  consulted  before  and  during  the  dissection  :  117, 
119-123 ;  PL  II,  Fig.  4 ;  PL  III,  Fig.  13  ;  PL  lY,  Fig.  14,  15, 16, 19. 

§  1147.  Opening  the  Cella  Media  of  the  Proccelia.— Aipiply  the 
edge  of  the  large  scalpel  along  a  line  2  mm.  dorsad  of  the  main  part 


le 

i 


DEMONSTRATION^    OF    THE    PROC(ELIA,  455 

of  the  callosum,  and  make  a  slight  incision.  Then  dip  the  scalpel 
in  alcohol,  and  cut  horizontally  along  that  line  so  as  to  remove  the 
dorsal  part  of  the  liemisphere. 

On  the  surfaces  so  exposed  note  the  ental  alba  (centrum  ovale) 
and  the  ectal  cinerea  (cortex) ;  also  the  undulations  of  the  line  of 
their  junction,  according  to  the  depth  of  the  fissures  between  the 
gyri.  Slice  the  removed  dorsal  piece  in  various  directions  so  as  to 
show  the  continuity  of  the  cinerea. 

If  the  surface  of  the  alba  of  the  ventral  part  is  uniform  in  color 
and  continuous,  remove  successive  slices,  not  more  than  .5  mm. 
thick,  until,  about  5  mm.  from  the  meson,  there  appears  a  group  of 
dark  points  ;  the  removal  of  another  very  thin  slice  will  then  expose 
the  summit  of  an  arched  cavity,  the  cella  media  of  the  procoelia, 
and  a  slightly  undulating  convex  surface,  the  cephalic  part  of 
which  is  the  fornix  and  the  caudal  the  hypocampa  (''  hippocampus 
major"). 

Opening  the  Medicornu  and  Exposure  of  the  Hypocampa. — 
Pusli  tb.e  syringotome  very  cautiously  latero-caudad  between  the 
hypocampa  and  the  cut  edge  which  overhangs  it,  and  then,  with 
the  scalpel,  remove  a  wedge-shaped  slice  so  as  to  expose  more  of 
the  hypocampa.  Ttepeat  the  operation,  bearing  in  mind  that  the 
direction  of  the  hypocampa  and  of  the  cavity — the  medicornu — into 
which  it  projects,  is  successively  caudad,  laterad,  ventrad,  cephalad 
and  mesad  ;  see  Fig.  119. 

The  anthropotoniical  terms  indicative  of  these  directions  are  "backward,  outward,  down- 
ward, forward  and  inward,  the  initial  letters  of  which  form  the  mnemonic  word  hodji. 

During  this  exposure  of  the  hypocampa,  there  is  danger  that  some 
part  of  its  surface  will  be  sliced  off,  and  the  syringotome  should  be 
used  as  an  explorer  before  each  incision.  When  near  the  tip  of  the 
LI.  hypocampcB,  be  especially  careful  not  to  cut  too  deeply  ;  the  tip 
of  the  cornu  is  here  separated  from  the  ectal  surface  by  a  very  thin 
lamina. 

When  the  entire  length  of  the  hypocampa  is  exposed,  pass  the 
convexity  of  the  tracer  along  its  caudal  border,  and  then  slice  off  the 
overhanging  portions  of  the  caudal  wall  of  the  medicornu.     Note 
that  the  width  of  the  medicornu  varies  somewhat,  but  that  there  is 
^^o  sign  of  the  caudal  prolongation  which,  in  man,  the  monkeys, 
^^Beals  and  some  cetacea,  forms  a  postcornu.    Note  also  two  slight 

|.. .........  .„,._._, 


456  ANATOMICAL     TECHNOLOGY. 

and  the  existence  of  something  like  the  terminal  expansion  which, 
in  the  human  brain,  is  called  the  "-pes  hypocampce,^'' 

§  1148.  Demonstration  that  the  Hypocampa  is  only  a  Modified 
Portion  of  the  Procoelian  Par ze^fe^.— Carefully  pass  the  tracer  be- 
tween the  opticus  and  the  caudal  border  of  the  hemisphere,  and 
rotate  it  so  that  the  point  may  penetrate  the  hypocampa  and  appear 
in  the  medicornu.  Withdraw  the  instrument  without  disturbing 
any  connections ;  see  Fig.  121  and  PI.  IV,  Fig.  18,  19. 

§  1149.  Opening  the  Prcecornu  and  Exposure  of  the  Striatum. — 
From  the  roof  of  the  procoelia,  cephalad  of  the  orifice  first  exposed, 
remove  a  thin  wedge-shaped  slice,  and  thus  more  completely  expose 
the  fornix,  which  is  seen  to  be  continued  along  the  cephalic  border 
of  the  hypocampa  as  a  flat  band,  the  fimbria. 

Cephalad  of  the  fornix  is  a  marked  elevation,  the  striatum ;  that 
part  of  the  procoelia  into  which  it  projects  is  the  praecomu.  Be- 
tween the  striatum  and  the  fornix  and  fimbria  is  a  depression,  the 
Sulcus  limitans,  into  which  projects  a  plexus,  the  proplexus.  The 
sulcus  and  the  plexus  may  be  traced  along  the  cephalic  border  of 
the  fimbria  to  near  the  tip  of  the  medicornu  ;  their  relations  will  be 
seen  better  at  a  later  stage  of  the  dissection. 

Note  that  the  cella  media  does  not  quite  reach  the  meson,  on 
account  of  the  continuity  of  the  fornix  and  the  hypocampa  with  the 
callosum.  As  will  be  seen  later,  the  only  place  w^here  the  procoelia 
does  reach  the  meson  is  at  the  bottom  or  mesal  end  of  the  Sulcus 
limitans,  where  the  porta  communicates  with  the  aula  and  thus 
with  the  mesal  series  of  coelise. 

Exposure  of  the  Mesal  Aspect  of  the  Striatum. — Along  a  line 
passing  dorso-ventrad  about  2  mm.  cephalad  of  the  chiasma,  make 
an  incision  1  mm.  deep  at  the  venter,  its  dorsal  end  reaching  the 
mesal  border  of  the  striatum,  as  already  exposed. 

From  the  mesal  aspect  of  the  olfactory  lobe  and  cephalic  part 
of  the  hemisphere  remove  a  slice  about  1  mm.  thick,  and  then,  with 
the  small  scalpel,  cut  successively  thin  wedge-shaped  slices  so  as  to 
expose  the  mesal  aspect  of  the  striatum  and  the  cavity,  the  prcB- 
cornu,  into  which  it  projects.  Note  the  somewhat  sharply  defined 
ridge  which  separates  the  mesal  from  the  dorsal  surface  of  the  stria- 
tum, and  the  greater  extent  of  the  former. 

§  1150.  Opening  the  Mhinocoelia. — The  ventro-cephalic  angle  of 
the  prsecornu  presents  a  slight  funnel-shaped  prolongation,  which 
may  be  traced  cephalad  into  the  Orus  olfactorium,  and  to  within 


DEMOXSTRATIOX    OF    THE    PORTA,  45 T 

about  2  mm.  of  the  end  of  the  Lobus.  This  canal  is  the  reduced 
representative  of  the  rhinoccBlia,  which  is  quite  large  in  most  lower 
vertebrates  and  in  many  mammals,  but  nearly  or  quite  obliterated 
in  man.  It  is  most  easily  traced  by  means  of  a  beaded  bristle.  If 
the  bristle  is  gently  moved  to  and  fro,  enough  of  the  coloring  matter 
of  the  bead  will  adhere  to  the  sides  of  the  canal  to  make  its  recogni- 
tion more  easy  as  it  is  exposed,  either  by  removing  very  thin  slices 
or  by  following  it  up  with  the  tracer.  The  diameter  of  the  canal  is 
about  .5  mm.,  but  it  is  usually  expanded  a  little  at  its  extremity. 

§  1151.  Demonstration  of  the  Por^<3^.— Recall  the  position  of  the 
aula  upon  the  meson.  Hold  the  brain  in  alcohol  or  water  so  that 
only  the  surface  cephalad  of  the  dorso-ventral  incision  projects 
above  the  surface;  then  blow  toward  the  aula  from  between  the 
striatum  and  the  mesal  wall  of  the  prsecornu.  The  escape  of  bub- 
bles of  air  will  demonstrate  the  connection,  through  the  j?or^<2,  of 
the  aula  with  the  proccBlia  ;  see  Fig.  120  and  PL  lY,  Fig.  16. 

§  1152.  Exposure  of  the  Prcecommissura. — Remove  the  cephalic 
end  of  the  brain  by  an  incision  at  about  the  middle  of  the  striatum, 
and  note,  on  the  cut  surface,  the  alternation  of  alba  and  cinerea  on 
account  of  which  the  name  was  applied.  Remove  other  slices,  cut- 
ting a  little  obliquely,  latero-cephalad,  and  note  the  increasing  dis- 
tinctness of  an  oblong  white  area,  the  oblique  section  of  a  fibrous 
fasciculus^the  praecommissura — which  unites  the  striata  and  Lobi 
olfactorii  across  the  meson,  and  which  has  been  observed  already  in 
the  examination  of  the  mesal  surface ;  see  also  PL  IV,  Fig.  14. 

Fig.  119. — Plaster  casts  of  the  medicornua,  inverted. 

Fi|?.  120. — Plaster  casts  of  the  diaccElia,  aula,  right  porta,  and  part  of  the  right  pro- 
coelia  of  the  sheep,  inverted. 

Fig,  121. — Diagram  of  a  transection  of  the  left  medicornu. 
Fig,  122. — Diagram  of  a  transection  of  the  diacoelia. 
Fig.  123. — Diagram  of  a  transection  of  the  porta. 

§  1153,  Fig.  119. — Plaster  casts  of  the  medicornua,  inverted;  xl.5.  Compare  with 
PI.  IV,  Fig.  15. 

Objects. — To  show  (1)  the  shape  and  extreme  curvature  of  these  parts  of  the  pro- 
coeliae  ;  (2)  that  they  are  completely  circumscribed,  and  do  not  open  by  a  "fissure  of 
Bichat "  upon  the  surface  of  the  hemisphere. 

Preparation. — The  plaster  was  injected  through  the  Foramen  infundibuU  while  the 
brain  was  supported  by  the  calva  {§  1125).  After  resting  undisturbed  for  an  hour,  tiie 
brain  substance  was  carefully  torn  and  cut  sufficiently  to  extricate  the  casts. 

Explanation.— The  ventral  ends  are  thinner  and  somewhat  expanded,  excepting  the 
•extremities,  which  are  decidedly  contracted.  This  contracted  finger-like  portion  is  wholly 
enclosed  by  true  nervous  parietes ;  all  the  rest  is  bounded  along  the  concave  (cephalic) 


yfnirtit^ 


I  "-■ '  '••-■'(,•■  ■',•'/.••'/.'  ■•;•••':■•' 

i:yl)jarti[\leyub  ■;'. ''.  ^j:] 


Fig.  123 

F.  callosalis  i 


I  F.  splenialis. 

1     1  pia 

'     I  araclmoidea 


medicommissura  / 


/  i  chiasma 
'diacoelia 


TRANSECTIOX    OF   THE    MEDICORNU.  459 

border  by  the  rima,  wliere  the  continuity  of  the  endyma  reflected  upon  the  proplexus,  and 
its  adhesion  along  the  fimbria  and  in  the  Sulcus  limitans  prevented  the  escape  of  the 
injected  material. 

§  1154.  Fig.  120. — Plaster  casts  of  the  diacoelia  (dorsal  portion),  aula,  and  right 
porta  and  praecornu  of  the  shee'p,  inverted  ;  x  1.5.  Compare  with  Fig.  113,  132  ;  PI.  Ill, 
Fig.  7, 10  ;  PI.  IV,  Fig.  16,  18,  19, 

Objects. — To  show  that  (1)  the  porta  permits  the  passage  of  injection  mass  from  the 
aula  into  the  procoelia  ;  (2)  the  aida,  porta  and  diacoelia  are  completely  circumscribed  ; 
(3)  the  porta  is  a  passage  of  some  length,  and  strongly  compressed. 

Preparation.— The  plaster  was  injected  through  the  Foramen  mfundihuU  (§  1125). 
Notwithstanding  all  possible  caution  in  disengaging  the  casts,  a  fracture  occurred  just 
between  the  porta  and  the  aula.  In  mounting,  a  slight  interval  was  left  between  the 
parts.  The  left  porta  and  procoelia  are  not  included  in  the  figure.  The  ridge  on  the  ven- 
tral aspect  of  the  cast  of  the  diacoelia  corresponds  with  the  dorsal  contour  of  the  medicom- 
missure.  The  cast  of  the  praecornu  is  quite  thin,  and  its  lateral  aspect  presents  a  sharp 
longitudinal  depression  corresponding  with  the  ridge  upon  the  striatum  (PI.  IV,  Fig.  16). 

Qualification. — The  three  following  figures  (121-123)  are  dia- 
grammatic representations  of  our  present  understanding  of  the 
relations  of  the  plexuses  to  the  membranous  parietes  of  the  porta, 
diacoelia  and  medicornu. 

It  is  probable  that  microscopic  sections  will  be  needed  in  order  to  elucidate  certain 
points,  especially  the  question  whether  the  proplexus  and  portiplexus  are  formed  by  the 
intrusion  of  the  entire  pia  or  only  of  vessels  therefrom  (§  1081).  We  have  thought  best 
to  represent  the  former  view  provisionally. 

Admitting  that  in  respect  to  this  detail  we  may  be  in  error,  we  wish  to  insist  upon  the 
more  essential  point,  viz.,  that  these  cavities  are  really  and  completely  circumscribed  by  the 
continuity  of  the  endyma  reflected  from  the  borders  of  the  nervous  parietes  upon  the 
plexuses. 

g  1155.  Fig.  121. — Diagram  of  a  transection  of  the  left  medicornu.  Compare  with 
Fig!  113, 119  ;  PI.  Ill,  Fig.  11  ;  PI.  IV,  Fig.  14,  15  ;  also  with  Duval  {2,  PI.  I,  Fig.  2). 

Object. — To  show  that  the  medicornu  is  completely  circumsofibed,  although  the  proper 
nervous  parietes  are  absent  from  the  porta  to  near  its  tip,  constituting  the  rima. 

Explanation. — The  figure  is  based  upon  Fig.  113,  but  the  cornu  is  disproportionally 
enlarged,  as  are  also  the  distances  between  the  hemisphere  and  the  mesencephalon  and 
diencephalon.     The  membranes  and  the  proplexus  are  also  introduced. 

It  should  be  remembered  that  this  represents  a  transection  of  the  length  of  the  medi- 
cornu, although,  from  the  fact  that  the  plane  of  section  is  horizontal  with  respect  to  the 
brain  as  a  whole,  the  cavity  closely  resembles  a  longitudinal  exposure  of  the  postcornu  of 
man  and  the  monkeys,  which  does  not  exist  in  the  cat. 

The  ectal  surfaces  of  the  hemisphere  and  of  the  epencephalon,  mesencephalon,  post- 
geniculatum  and  praegeniculatam  are  covered  by  pia.     The  cornu  is  lined  by  endyma. 

In  the  frog  and  presumably  in  the  embryo  of  the  cat,  the  entire  length  of  the  medi- 
cornu has  complete  nervous  parietes,  as  has  the  tip  of  the  eornu  in  the  cat  and  man.  The 
endyma  and  the  pia  would  then  be  wholly  separated. 

But  the  abrogation  of  the  nervous  continuity  between  the  border  of  the  fimbria  and 
the  Sulcus  limitans  permits  the  vessels  of  the  pia,  or  perhaps  a  fold  of  the  pia  itself,  to 


400  ANATOMICAL     TECHNOLOGY. 

intrude  apparently  into  the  cornii.  In  so  doing,  however,  the  endyma  is  carried  before 
so  as  to  encompass  the  fold  or  the  v^essels,  as  an  abdominal  viscus  is  surrounded  by  the 
peritoneum.  Hence,  also,  the  cornu  is  really  completely  enclosed  by  the  endyma,  even 
where  the  nervous  parietes  are  absent. 

The  general  name  striatum  is  given  to  the  thickened  part  of  the  hemisphere,  but  the 
Cauda  striati  and  toBnia  are  not  represented, 

§  1156.  Fig.  122. — Transection  of  the  brain  through  the  diacoelia.  Compare  with 
Fig.  120;  PI.  Ill,  Fig.  7,  10, 13  ;  PI.  IV,  Fig.  15. 

Objects. — To  show  (1)  that  the  diacoelia  has  a  roof  (diatela)  independent  of  the  velum 
and  fornix  ;  (2)  that  the  dorsal  surface  of  the  thalamus  is  ectoco&lian  ;  (3)  that  the  arach- 
noidea  does  not  reacli  the  bottom  of  the  interhemi spheral  fissure. 

Explanation. — The  diaccelia  is  seen  to  be  divided  into  a  larger  ventral  and  a  smaller 
dorsal  portion  by  the  large  medicommissura.  The  walls  (lateral  parietes)  of  both  portions 
are  the  thalami. 

The  dorsal  surface  of  the  thalamus  is  convex  and  covered  by  pia.  The  mesal  is  nearly 
flat  and  covered  by  endyma.  The  rounded  angle  between  these  two  surfaces  presents  a 
ridge,  the  habena,  and  a,  furrow,  the  Sulcus  habenae. 

The  endyma  leaves  the  thalamus  along  the  sulcus  (PI.  Ill,  Fig.  7),  and  is  reflected  first 
dorsad  and  then  mesad  so  as  to  roof  in  the  diacoelia  completely,  as  indicated  in  PI.  Ill, 
Fig  10,  and  by  the  definite  form  of  the  plaster  cast  shown  in  Fig.  120. 

In  the  frog  and  in  the  embryo  mammal,  the  only  parts  dorsad  of  the  diacoelia  are  this 
endyma  and  the  pia  and  arachnoid  which  envelope  the  entire  brain,  together  constituting 
a  membranous  diatela.  But  in  the  adult  mammal,  the  hemispheres  not  only  project  dor- 
sad of  the  diencephalon,  but  unite  along  the  meson  so  as  to  form  the  callosum  and  the 
mesal  part  of  the  fornix,  fornicommissure  (see  p.  4006).  The  fornix  and  callosum  are 
])riinarily  dorsad  of  and  separate  from  the  diatela,  and  the  latter  is  often  ignored  on 
account  of  its  tenuity.  The  relation  of  the  diaplexus  to  the  diatela  is  not  altogether  clear. 
In  the  figure  the  diaplex  is  represented  as  a  fold  of  pia  intruded  into  the  diacoele  and,  as 
i^  always  the  case,  carrying  the  endyma  before  it.  The  two  veins  of  the  velum  (venae 
Galeni)  are  represented.  The  proplexus  is  the  lateral  and  principal  part  of  the  prosoplex. 

§  1157.  Fig,  123. — Diagram  of  a  transection  of  the  porta  (foramen  of  Monro),  Com- 
pare Fig„  113,  120,  and  PI.  Ill,  Fig.  18,  19. 

Object. — To  show  that  the  porta  is  com/pletdy  circumscribed,  notwithstanding  the  ab- 
sence of  the  proper  nervous  parietes  at  the  dorsal  end  where  it  adjoins  the  rima. 

Description. — The  plane  of  section  is  dorso-ventral  and  longitudinal,  ])ractically  paral- 
lel with  the  meson.  Regarding  the  porta  as  a  short  passage  with  an  approximately  trans- 
verse direction,  it  is  here  transected. 

The  larger  mass  is  the  dorso-cephalic  portion  of  the  thalamus.  Cephalad  and  dorsad 
of  it  is  the  fornix  with  its  Columna,  these  being  continuous  with  the  corresponding  half 
of  the  septum  lucidum. 

The  dorsal  surface  of  the  thalamus  is  convex  and  covered  by  pia  (velum),  but  the 
cephalic  surface  is  concave  and  covered  by  endyma.  In  man  and  in  some  cats,  the  bound- 
ary between  the  two  surfaces  is  indicated  by  a  more  or  less  distinct  tubercle.  In  all  cases 
there  is  a  point  of  reflection  of  the  endyma  cephalad  toward  the  fornix. 

The  corresponding  surfaces  of  the  fornix  are  likewise  pial  and  endymal  ;  there  is  no 
elevation  of  the  surface  to  mark  the  boundary  between  the  two,  but  nearly  opposite  the 
X)oint  of  reflection  of  the  endyma  from  the  thalamus  it  is  reflected  also  from  the  fornix. 

So  much  of  the  interval  between  the  thalamus  and  the  fornix  as  lies  ventrad  of  these 
two  points  of  reflection  is  the  porta.     Primitively,  there  is  reason  to  believe,  the  endyma 


EXPLANATION    OF    THE    PLATES.  4G1 

continued  directly  across,  as  tlie  liuinor  of  the  original  nervous  roof.  The  abrogation  of 
the  nervous  portion  of  that  roof  [)ermitted  the  intrusion  of  the  pia  (or  of  its  vessels)  to 
form  the  portiplexus,  upon  which  the  endyma  is  reflected. 

The  boundaries  of  the  porta  are,  then,  as  follows  :  caudal,  the  thalamus  ;  cephalic,  the 
fornix  ;  ventral,  the  continuity  of  the  two  ;  dorsal,  the  endyma,  reflected  upon  the  porti- 
plexus. 


EXPLANATION   OF  THE  PLATES. 

§  1158.  The  four  lithographic  plates  of  the  brain  illustrated  the 
senior  author's  paper  {14)  in  the  Proceedings  of  the  Philosophical 
Society  of  Philadelphia,  by  courtesy  of  which  they  are  included  in 
the  present  work.  With  slight  alterations,  the  following  explana- 
tions are  the  same  as  given  in  that  paper,  but  quotation  marks  are 
used  only  where  specially  needed. 

As  with  the  other  figures  of  the  brain,  all  of  the  preparations  from  which  the  figures 
were  drawn  are  in  the  Museum  of  Cornell  University,  and  are  acxiessible  for  examination 
to  those  who  may  desire  to  verify  the  figures  or  the  descriptions. 

In  most  cases,  each  figure  is  based  upon  more  than  one  preparation.  Encephalotomists 
need  not  be  reminded  of  the  difficulty  of  obtaining  a  preparation  which  shows  many  points 
of  structure  equally  well.  Since  the  present  account  is  only  general,  and  does  not  aim  to 
indicate  individual  peculiarities,  or  those  of  sex,  breed  or  age,  most  of  the  figures  may  be 
regarded  as  representing  what  may  be  called  an  average  cat's  brain.  It  is  obvious  that  a 
very  large  number  of  specimens  would  need  to  be  carefully  compared  in  order  to  confer 
upon  any  generalization  respecting  sex,  etc.,  a  trustworthy  character. 

"  Most  of  the  figures  are  twice  the  diameter  of  the  preparations,  and,  with  the  excep- 
tion of  Fig.  1  and  2,  it  would  have  been  better  to  make  the  enlargement  four  or  five 
diameters.  Aside,  however,  from  the  greater  expense  which  this  would  have  involved, 
such  a  degree  of  enlargement  would  have  rendered  it  not  only  possible  but  necessary  to 
show  certain  details  of  structure  upon  which  my  information  is,  at  present,  imperfect. 

"All  of  the  figures  have  been  drawn  from  my  owti  preparations  by  Miss  G.  D.  Clem- 
ents, B.  S.,  at  the  time  a  student  in  the  Natural  History  Course  in  Cornell  University. 

"Artists  and  anatomists  who  have  undertaken  to  represent  the  details  of 'encephalic 
structure  understand  the  difficulties  of  the  task,  and  will  admit  that  the  omissions  and 
inaccuracies  to  which  attention  is  called  in  the  descriptions  are  both  few  and  unimportant 
compared  with  the  general  thoroughness  of  the  work.  Indeed,  for  all  the  deficiencies,  I 
hold  myself  much  more  responsible  than  the  artist,  by  whom  some  of  the  figures  were 
drawn  at  least  four  times,  twice  upon  stone." 

The  abbreviations  are  explained  in  §§  1127,  1128  ;  synonyms,  references  and  brief 
descriptions  are  given  in  the  latter  part  of  this  chapter  (§§  1181-1333). 

K  PLATE   I. 

§1159.    Fig.  I.— The  dorsal  aspect  of  the  brain  ;   x2. 

"  The  general  form  and  some  of  the  fissures  are  drawTi  from  Prep's  288  and  289,  the 
bisected  brain  of  a  white  and  Maltese  ?  ;  but  the  fissures  of  the  right  hemisphere  are 
derived  from  several  different  preparations. 


462  ANA  TOMICAL    TECHNO  LOGY. 

"  The  Lobi  olfactorii  (X.  ol.)  are  made  Bomewbat  too  prominent ;  there  is  considerable 
difference  among  cats  in  this  respect,  although  much  less  than  among  dogs. 

'■  The  general  features  of  the  cerebellum  {chl.)  are  well  shown.     The  Lobi  laterales 
{L.  I.)  have  only  a  fair  proportion  to  the  median  lobe  or  vermis  {vm.),  instead  of  the  pre- 
ponderance which  they  have  in  the  human  brain      The  lateral  contortion  which  charac- 
terizes the  caudal  aspect  of  the  vermis  in  adult  cats  (as  shown  in  my  paper,  11,  221,  PI.  I 
Fig.  1  and  2)  does  not  affect  the  dorsal  part. 

"  As  already  stated,  the  fissures  of  the  hemispheres  are  differently  represented  upon  the 
two  sides.  The  combination  of  the  two  kinds  of  fissural  arrangement  in  a  single  fio-ure 
serves  to  illustrate  the  extent  of  the  lateral  variation  and  compensation  to  which  attention 
was  called  by  me  in  1873  (1 1,  382)." 

§  1160.  Fig.  2.  —  The  sinistral  aspect  of  the  brain.  From  Prep.  288 ;  x  2. 
Compare  with  Fig.  124. 

The  Lobus  olfactorius  {L.  ol.)  is  made  somewhat  too  prominent.  The  curved  line 
upon  its  lateral  surface  indicates,  approximately,  the  boundary  of  the  more  cephalic  por- 
tion of  the  pero  or  ectal  layer,  whence  arise  the  Nervi  olfactorii.  These  nerves  are  not 
shown. 

The  features  of  the  Crus  olfactorium  indicated  by  Im.  cin.  and  Im.  alb.  are  more  fully 
shown  upon  Fig.  3. 

The  Nervus  opticus  (iV.  op.)  projects  from  the  ventral  margin  of  the  figure,  and  the 
Fissura  Sylviana  {F.  S.)  is  seen  dorso-caudad  of  it. 

The  ventral  end  of  this  fissure,  as  is  always  the  case  in  the  cat,  joins  the  fissure  which 
forms  the  dorso-lateral  boundary  of  the  Tractus  olfactorius  (7r.  o^.),  and  the  cephalic  and 
caudal  divisions  of  that  fissure  are  called  respectively  rhinalis  and  postrhinalis  [FF.  rh. 
and  prh.).  So  much  of  the  hemisphere  as  lies  caudad  of  the  F.  Sylviana  forms  the  Lobus 
temporalis  {L.  tmp.\  the  ventral  extremity  of  which  is  the  Lobulus  hypocampas  {LI. 
hmp). 

The  cerebellum  {chl.)  presents  the  narrow  median  lobe  or  vermis  (vm.),  and  the  Lobva 
lateralis  {L.  I.).  Near  the  ventro-cephalic  angle  of  the  latter,  two  or  three  of  the  lamina? 
of  the  second  tier  project  as  the  Lobulus  appendicularis  {LI.  ap.\  which  is  seen  better  in 
Fig.  3. 

The  metaplexus  shown  in  Fig.  3  {mtpx.)  has  been  removed  so  as  to  expose  the  promi- 
nent Eminentia  auditoria  {Em.  au.),  whence  springs  the  N.  auditorius  {N.  au.). 

Just  ventrad  of  the  eminence  is  the  trapezium  {tz.),  and  cephalad  of  this  is  the 
pons  {pn.). 

Between  the  pons  and  the  hemisphere  appears  a  part  of  the  Crus  cerebri  {Cr.  cb.),  and 
cephalad  of  this  is  the  slender  N.  trochlearis  {H.  tr.),  which,  by  inadvertence,  seems  to 
emerge  from  the  F.  postrhinalis  instead  of  from  between  the  cerebellum  and  the  hemi- 
sphere. 

The  N.  trigeminus  (iV.  trg)  has  been  cut  short,  in  order  the  more  clearly  to  show  that 
it  usually  emerges  just  caudad  of  the  pons,  and  not  through  it  as  in  man. 

The  remaining  nerve  origins  are  indicated  only  by  dots.  Those  of  the  NN.  glosso- 
pharyngeus,  vagus  and  accessorius  {NN.  gph.,  v.  and  ac.)  form  a  series.  At  the  side  of 
the  myelon,  near  the  dorsal  and  ventral  borders,  are  seen  the  origins  of  the  first  cervical 
nerve  {N  cv.  1). 

In  this  figure  the  fissures  are  accurately  represented  as  they  are  in  the  preparation, 
excepting  that  the  small  F.  lunata  {F.  In.)  has  been  added  from  Prep's  519  and  520.  The 
small  F.  intermedia  might  well  have  been  inserted  between  the  dorsal  ends  of  the  FF. 
anterior  and  postica  {FF.  a.  and  p.). 


EXPLANATION    OF    THE    PLATES.  463 


PLATE  II. 


fc 


§  1161.  Fig.  3.  —  The  basis  encephali,  or  ventral  aspect  of  the  brain ;  x  2. 
Compare  with  Fig,  116. 

The  proportions  and  general  features  are  from  the  brain  of  an  adult  $ ,  Maltese  and 
white,  Prep's  288,  289.  Some  details  of  the  Area  praechiasmatica  (the  region  cephalad 
of  the  chiasma)  are  from  461  and  527  ;  of  the  Ar.  postpontilis  (the  region  caudad  of  the 
pons)  from  358,  454  and  491  ;  and  of  the  intermediate  Ar.  cruralis  from  422,  506  and  527. 

Most  of  the  nerves  and  cerebral  fissures  are  lettered  on  the  right  side,  and  most  of  the 
other  parts  on  the  left.  Some  of  the  left  nerves  are  cut  short,  and  the  left  N.  trochlearis 
is  not  shown  at  all. 

The  Lobi  olfactorii  {LI.  ol.)  are  made  too  long,  and  the  hypophysis  {hph,)  is  too  short. 

Attention  is  called  to  the  following  points,  chiefly  in  comparison  with  the  human 
brain  : — 

The  absence  of  a  distinct  Radix  intermedia  (Ex.  in.)  of  the  Crus  olfactorium,  corre- 
sponding with  the  so  called  "  middle  root  of  the  olfactory  nerve  "  in  man.  The  part  so 
designated  upon  the  plate  is  apparently  only  an  area,  comparatively  undifEerentiated, 
between  the  more  or  less  fibrous  tracts  forming  the  Radix  mesahs  and  Rx.  lateralis. 

The  turning  of  the  Rx.  mesalis  {Ex.  ms.),  ("internal  root"),  over  the  margin  of  the 
brain  so  as  to  appear  upon  the  meson. 

The  distinction  of  the  Rx.  lateralis  (Ex.  I.),  (*'  external  root  "),  into  a  lateraj  gray  and  a 
al  white  tract,  the  Limes  cinerea  (Lm.  cin.)  and  the  Lm.  alba. 

The  great  extent  of  the  (Locus)  praeperforatus  (pn?/.),  and  its  division  into  a  cephalic 
more  prominent  portion  (PL  p.)  and  a  caudal  depressed  portion  (Pt.  d.).  Both  x>ortions 
are  *'  perforated,"  but  the  degree  of  furFowing  of  the  Pt.  promiTiens  varies  considerably. 
These  furrows  exist  in  some  other  Carnivora. 

The  width  of  the  hypophysis  (hph.)  and  the  crenation  of  its  caudal  border,  indicating 
the  existence  of  an  ental  subsphcrical  mass,  which  is  covered  by  an  ectal  layer,  the  thin- 
^Hbss  of  which,  in  the  caudal  region,  permits  the  contour  of  the  former  to  be  seen. 
^H  The  slight  degree  of  separation  of  the  albicantia  (abn.),  which  are  here  nearly  con- 
^Haled  by  the  hypophysis,  but  more  fully  shown  in  Fig.  12. 
^H  The  distinctness  of  the  cimbia  (cmb.),  which  is  better  seen  in  Fig.  11. 
^H*  The  slight  extent  of  the  true  postperforatus  (ppf.)  ;  the  only  part  which  is  really 
^Hperforated  "  is  a  small  area  just  caudad  of  the  albicantia,  and  partly  hidden  by  them. 
^B  The  less  caudo-cei)halic  extension  of  the  pons  (pn.) ;  this  exposes  more  of  the  Area 
t^mtercruralis  (Ar.  ic.)  than  in  man,  and  uncovers  the  trapezium  (tz.),  which,  in  man,  is 
wholly  concealed.     Connected  also  with  this  feature  of  the  pons  is  the  fact  that  the  N. 
abducens  (JV.  abd.)  passes  directly  cephalad  from  its  origin  a  little  caudad  of  the  pons, 
whereas  in  man  it  is  forced  to  curve  around  the  caudal  border.     Finally,  the  N.  trigemi- 
nus (iV.  irg.),  instead  of  emerging  through  the  pons  near  the  cephalic  border  as  in  man, 
emerges  close  to  its  caudal  border  or  clears  it  completely  ;  see  Chap.  XL 

The  greater  extent  of  the  Ar.  cruralis,  which  may  be  ascribed  both  to  the  less  extent 
of  the  pons  and  the  less  degree  of  flexure  of  the  whole  brain  at  the  mesencephalic  region. 
The  greater  width  of  the  Tractus  postrhinalis  (Tr.prh),  which  includes  the  surface 
of  the  Lobulus  hypocampae  (LI.  hmp.).     In  man,  indeed,  this  part  is  hardly  visible  on 
account  of  the  prominence  of  the  convolutions  laterad  of  the  F.  postrhinalis. 

The  apparent  origin  of  the  N.  oculomoiorius  (N.  ocm.)  laterad  of  the  meson  and  just 
caudad  of  the  cimbia  (cnib.). 


464  ANATOMICAL   TECHNOLOGY. 

The  appearance  of  a  division  of  the  ectal  layers  of  the  pontile  fibers  into  three  groups, 
cephalic,  caudal  and  intermediate,  the  latter  partly  overlapped  by  the  other  two. 

The  appearance  of  a  faint  band  crossing  the  trapezium  a  little  obliquely  between  the 
origins  of  the  NN.  abducens  {N.  abd.)  and  facialis  (iV./.).  The  distinctness  of  this  band 
varies. 

The  origin  of  the  N.  hypoglossus  (iV.  hg.)  at  the  lateral  border  of  the  Area  elliptica 
{Ar.  el.),  which  is  thought  by  some  (Am.  Jour,  of  Neurology,  etc.,  I,  102)  to  be  the  surface 
of  the  oliva  or  "  olivary  body  "  of  man.  The  determination  of  this  point  involves  some 
comparisons  and  sections  which  we  have  not  yet  made. 

The  close  association  of  the  roots  of  the  JS'JV.  glossopharyngeus  {N.  gph.),  vagus  {N.  v.) 
and  acceasorius  {JSf.  ac.)     See  Stowell  {1)  and  Chap.  XI. 

The  marked  prominence  of  the  ventro-lateral  region  of  the  metencephalic  continuation 
of  the  Columna  lateralis  myelonis  {Clm.  I.),  forming  an  elevation  to  which  I  have  applied 
the  provisional  name  Area  ovalis  {Ar.  ov,),  but  which  is  thought  by  some  (Am.  Jour,  of 
Neurology,  etc.,  I,  102)  to  represent  the  Tuberculum  Rolandil. 

The  absence  of  any  superficial  decussation  of  the  pyramides  (py.).  Hence,  the  F.  ventri- 
mesalis  {F.  xms.),  or  "  anterior  fissure,"  is  uninterrupted.  The  F.  ventrilateralis  (F.  vl.)  is 
deflected  at  the  caudal  end  of  the  Area  elliptica. 

§  1163.  Fig.  4. — The  mesal  surface  of  the  right  hemiencephalon  ;  x  2.  Compare 
Fig.  114. 

The  general  features  are  from  the  same  brain  as  Fig.  3,  but  some  are  derived  from 
Prep's  290,  304  and  454. 

The  surfaces  shown  in  this  figure  are  of  four  kinds,  as  follows  (§  1137) : — 

(1)  The  natural  surfaces  which  are  covered  by  pia.  These  are  the  mesal  aspects  of  the 
hemisphere  (hem.)  and  the  Lohus  olfactorius  {L.  ol.). 

(2)  The  natural  mesal  surface  {Ar.  spt.)  of  thfe  right  half  of  the  septum  lucidum,  which, 
in  the  cat,  is  in  contact  with  its  platetrope,  or  separated  therefrom  only  by  a  thin  layer  of 
connective  tissue.  We  have  never  observed  an  interval  corresponding  to  the  pseudo- 
ccelia  or  "  fifth  ventricle  "  of  man, 

(3)  The  natural  endymal  surfaces  of  the  true  cozlim  or  "  ventricles."  Of  course  the  pro- 
coelise  ("  lateral  ventricles  ")  do  not  appear. 

(4)  The  cut  surfaces  of  the  commissures  and  other  parts  which  cross  the  meson  or  lie 
upon  it.  In  the  cerebellum  (cbl.),  the  relative  areas  of  the  ental  alba  and  the  ectal  dnerea, 
forming  the  arbor  nitce  {arb.),  are  indicated  by  the  shading  ;  with  less  definiteness,  the  alba 
is  shown  in  the  callosum  (cL),  the  fornix  (/.),  the  prcecommissiira  {prcs.),  the  postcommis- 
sura  {pes.),  the  commissura  habenarum  {cs.  7i.),  and  the  chiasma  {ch.).  The  section  of  the 
medicommissura  {mcs.)  should  appear  as  if  composed,  at  least  chiefly,  of  cinerea,  but  no 
attempt  has  been  made  to  indicate  the  nature  of  the  cut  surfaces  of  the  Crista  fornicis 
{Crs.f.),  the  terma  {t.),  the  hypophysis  {hph),  the  infundibulum  {inf.),  the  conarium  {en.), 
the  optici  and  postoptici  {op.  and  pop),  the  valoula  {vv.),  the  Crura  cerebri  {Cr.  cb.),  the 
metatela  {mttl.),  or  the  rest  of  the  epencephalon  and  metencephalon  {mten.).  The  ex- 
tent of  the  transverse  fibers  of  the  pons  {pn.)  should  have  been  represented,  at  least 
approximately. 

So  much  of  the  cephalic  boundary  of  the  au^a  {a.)  as  intervenes  between  the  prcecom- 
missura  (p?YS.)and  the  crista  {Crs.f)  is  very  thin,  and  is  too  indistinctly  shown  in  the 
figure.  Neither  here  nor  at  any  other  point  is  there  any  such  interruption  of  the  wall  as 
would  form  a  communication  between  the  true  ccelise  and  the  pseudocoelia  or  the  ectal 
surface  of  the  brain.     It  is  probable  that  the  presence  of  such  a  communication  as  is 


PROC.    AMER    PHILOS.    SOC    VOL  XIX       1881 


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PROC.    AMER     PHIL05     SOC     VOL  XIX       1881 


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EXPLANATION    OF    THE    PLATES.  -^5 

ascribed  to  the  human  embryo  and  to  some  animals  in  Qaain  (A,  II,  543)  is  due  to  the 
artificial  rupture  of  the  natural  connections  ;  see  p.  536  of  the  same  work. 

Attention  is  called  to  the  following  points,  chiefly  in  comparison  with  the  human 

brain  : — 

The  appearance  of  the  Rx.  mesalis  {^Rx.  ms.)  on  the  meson,  and  the  presence  of  two 
shallow  fissures,  postradicalis  and  pr£eradicalis  {FF.  prd.  and^rrrf.)  between  it  and  tne 
adjoining  surfaces  of  the  hemisphere. 

The  large  size  of  the  commissQres,  especially  the  medicommissura,  which  nearly  fills 
the  dorsal  part  of  the  diacoelia  {de.). 

The  non-appearance  of  the  porta  when  the  meson  is  viewed  squarely  ;  it  is  doubtful 
whether  the  human  "  foramen  of  Monro  "  is  really  visible  from  the  meson. 

The  less  extent  of  the  callosum,  especially  of  its  rostrum  {rm.).  In  some  humar. 
brains  the  rostrum  does  not  extend  so  far  as  is  usually  represented. 

The  darker  spot  on  the  section  of  the  hypophysis  represents  the  space  occupied  by  the 
ental  mass,  which  has  been  removed. 

The  relations  of  the  pia  are  not  indicated  at  all,  and  are  not  well  understood,  especially 
between  the  cerebellum  and  the  metencephalon  and  mesencephalon. 


PLATE  III. 

With  the  exception  of  Fig.  13,  all  the  figures  upon  this  plate  represent  the  natural 
surfaces  of  regions  which  are  more  or  less  completely  concealed  by  other  parts  in  the 
undissected  brain. 

§  1163.  Fig.  5.  —  The  cephalic  aspect  of  the  prosencephalon.  From  Prep. 
294-,   x2. 

The  hardened  brain  was  transected  at  the  F.  postica,  so  that  the  preparation  includes 
only  the  cephalic  two  thirds  of  the  prosencephalon. 

The  drawing  represents  the  preparation  tilted  up  so  as  to  expose  the  ventral  aspect 
foreshortened. 

As  compared  with  Fig.  6,  this  might  well  have  been  made  of  the  natural  size.  A  less 
regularly  symmetrical  brain  would  have  been  more  instructive.  One  of  the  Crura  olfae- 
toria  should  have  been  divided  at  a  little  greater  distance  from  the  prosencephalon. 

So  far  as  appears  in  the  figure,  the  fissures  are  remarkably  alike  upon  the  two  sides  ; 
the  left  F.  ansata  {F.  an.),  however,  only  the  meso-cephalic  end  of  which  appears  in  the 
figure,  presents  the  somewhat  unusual  but  very  sugpfestive  condition  of  entire  independ- 
ence of  the  lateralis  (which  is  invisible)  and  the  coronalis  {F.  cor.).  On  the  right  side  it 
is  joined  by  the  former  fissure. 

The  right  F.  Sylviana  {F.  8.)  is  shorter  than  the  left,  and  presents  a  slight  terminal 
bifurcation  which  is  not  shown. 

In  consequence  of  the  removal  of  the  Lobi  olfactorii  and  the  tilting  of  the  whole  prepa- 
ration, so  much  of  the  F.  rhinalis  {F.  rh.)  as  lies  cephalad  of  its  union  with  the  super- 
orbitalis  [F.  so.)  is  practically  obliterated,  and  the  remainder  of  it  is  so  foreshortened  as  to 
appear  as  an  insignificant  intermediate  portion  of  an  extensive  u-shaped  fissure  formed  by 
the  FF,  Sylviana  (i<!  8.)  and  superorbitalis  {F.  so.).  "The  appearances  thus  presented 
are  suggestive  in  view  of  the  idea  of  Meynert  ( /,  12),  which  I  also  entertained  at  one  time 
(11,235),  that  the  F.  superorbitalis  represents  the  'anterior  branch'  of  the  human 
F.  Sylviana,  and  that  the  intervening  region  corresponds  to  the  '  operculum.' " 

A  slight  preponderance  of  the  left  hemisphere  just  caudad  of  the  F.  Sylviana  is  some- 
30 


i 


466  ANAT03nCAL     TECHNOLOGY. 

what  exaggerated  in  the  figure,  and  the  Crura  olfactoria  (CV.  ol.)  should  differ  less  in  form 
and  in  their  distance  from  the  meson. 

The  FF.  olfactoria  {F.  ol.)  appear  as  little  more  than  shallow  furrows. 

On  account  of  the  foreshortening  of  the  ventral  aspect,  the  line  of  separation  of  the 
Portio  prominens  {Pt.  p.)  and  the  Pt.  depressa  {Pt.  d.)  is  indistinct.  The  hypocampal 
lobule  {LI.  Jimp.)  on  each  side  has  been  flattened  by  pressure,  and  is  so  represented. 

§  1164.  Fig.  6.— The  caudal  aspect  of  the  prosencephalon,  with  part  of  the  dien- 
cephalon.     From  Prep.  292,  an  adult  $  ;    x  1. 

The  diencephalon  has  been  transected  so  as  to  leave  a  concave  surface  which,  at  the 
meson,  is  close  to  the  caudal  border  of  the  medicommissura  {mcs.),  but  rises  at  the  sides  so 
as  to  coincide  nearly  with  the  caudal  surface  of  the  prosencephalon. 

The  postcommissura  has  been  removed,  and  the  slender  transverse  band  {Cs.  Ii.)  just 
ventrad  of  the  splenium  (sp.)  is  the  Commissura  habenarum.  Had  the  postcommis- 
sura been  left,  the  intervening  space  would  be  a  foramen,  I*^.  conarii. 

The  shallow  depression  of  the  ventricaudal  surface  of  each  hemisphere  just  laterad  of 
the  splenium  represents  the  area  of  contact  of  the  opticus. 

The  cerebral  fissures  are  markedly  unsj'mmetrical,  and  thus  in  contrast  with  those  of 
Fig.  5.  The  right  postrhinalis  {F.  prh.)  is  the  longer,  and  the  right  postsylviana  {F.  ps.) 
joins  the  supersylviana,  although  the  place  of  union  does  not  appear  in  the  figure.  On 
the  contrary,  by  reason  of  the  perspective,  it  seems  to  be  joined  by  the  F.  medilateralis 
{F.  ml.). 

The  hypocampal  lobules  {LI.  hypocampm)  have  their  proper  rounded  form  in  this 
preparation. 

Part  of  the  diacoelia  {dc.)  appears  dorsad  of  the  medicommissura,  and  part  on  its  ven- 
tral side  (Fig,  122).  In  man,  the  commissure  is  smaller  and  the  ccelia  correspondingly 
more  extensive.  On  account  of  the  removal  of  the  hypophysis  and  infundibulum,  the  dia- 
coelia opens  freely  at  the  Fm.  infundibuli  {Fm.  inf.). 

§  1165.  Fig.  7. — The  dorsal  aspect  of  the  diencephalon  and  mesencephalon. 
From  Prep's  1'97  and  494,  adult  $  ,  423,  a  nearly  adult  ?  ,  and  506  ;    x  2. 

The  principal  features  of  this  figure  were  drawn  from  Prep,  506.  The  preparation  was 
made  by  lifting  the  caudal  ends  of  the  hemispheres  and  gradually  separating  them,  with 
the  callosum,  fornix  and  velum,  from  the  subjacent  parts.  The  epencephalou  and  meten- 
cephalon  were  then  removed  by  a  transection  just  caudad  of  the  postoptici. 

The  valvula  (w.)  is  drawn  as  it  appeared  in  Prep.  494,  after  inflation  by  blowing  air 
from  the  diacoelia  through  the  mesocoelia  or  iter. 

The  Commissura  habenarum  {Cs.  h.)  is  really  more  distinct  in  Prep.  397  than  appears 
in  the  figure.  The  habenae  {h),  their  sulci  {SI.  7i.)  and  the  lines  of  reflection  of  the 
endyma  are  taken  from  Prep.  422,  and  their  distinctness  is  not  exaggerated  in  the  figure  ; 
see  Fig.  122. 

The  complete  roof  of  the  diacoelia,  the  diatela  {dtl.),  is  shown  in  Fig.  10, 

As  compared  with  the  homologous  parts  in  man,  the  feline  postoptici  {pop.)  and  geni- 
culata  {pgn.  and  prgn.)  htq  larger,  while  the  thalami  proper  {th.)  seem  to  be  only  the 
mesal  continuations  of  the  prccgeniculata  {prgn.),  and  to  lack  altogether  the  pulvinar  or 
"  posterior  tubercle  "  of  man. 

§  1166.  Fig.  8.— The  caudal  aspect  of  the  mesencephalon,  with  parts  of  the 
adjoining  regions.     From  Prep,  506  ;    x  1. 

The  plane  of  transection  coincides  nearly  with  the  caudal  surface  of  the  postoptici 
{pop^,  and  has  divided  the  pons  { pn.)  a  little  caudad  of  its  middle.     The  valvula  {vc.)  was 


EXPLANATION    OF    THE    PLATES.  467 

torn  from  this  preparation,  and  the  line  of  its  attachment  is  not  distinctly  shown.  Some- 
thing of  its  position  may  be  judged  from  Fi^.  7.  The  caudal  orifice  of  the  mesocoelia 
(msc.)  is  shown  here  as  a  nearly  regular  circular  spot ;  in  reality,  it  presents  a  slight  mesal 
extension  at  both  the  dorsal  and  ventral  sides.  Indeed,  when  carefully  examined,  the  so 
called  "  aquaeductus  Sylvii  "  is  far  from  being  a  perfectly  simple  and  uniform  tube  ;  its 
form  in  man  is  indicated  in  Reichert's  Fig,  31  (A,  Taf.  4).  Among  the  lower  mammals  it 
is  usually  larger,  and  with  the  lower  vertebrates  it  often  has  the  proportions  of  a  true 
coelia,  with  lateral  extensions. 

The  cimbia  (cmb.)  is  partly  seen  on  the  right.  The  geniculata  {pgn.  and  prgn.)  do  not 
project  as  far  as  they  should.  The  optici  are  wholly  hidden  from  view  by  the  prominent 
postoptici  (pop). 

§  1167.  Fig.  9. — The  sinistral  aspect  of  the  mesencephalon  and  diencephalon. 
From  Prep's  491  and  506  ;    x  2; 

The  only  cut  surface  shown  in  this  figure  is  that  caused  by  the  oblique  transection 
between  the  diencephalon  and  the  prosencephalon ;  the  plane  of  section  followed  the 
cephalic  border  of  the  Tractus  opticus  {Tr.  op.),  and  corresponds  with  the  Sulcus  limitans 
between  the  thalamus  and  the  striatum. 

Crossing  the  crus  {Or.  cb.),  just  caudad  of  the  postgeniculatum  (pgn.),  is  seen  the 
cimbia  (cmb.). 

*'  Upon  this  figure  should  appear  the  Lemniscus  superior  and  L.  inferior,  and  the  posi- 
brachium  and  prcebrachium ,  provided  they  exist  in  the  cat  as  distinct  parts  visible  at  the 
surface.  I  have  not  been  able  to  satisfy  myself  respecting  their  exact  position  and  limits 
in  the  human  brain,  and  refrain  from  expressing  any  opinion  concerning  them." 

§  1168,  Fig.  10. — The  dorsal  aspect  of  the  diencephalon,  including  the  diatela. 
From  Prep.  301,  a  half  grown  ^ ;    x  1. 

The  object  of  this  figure  is  to  show  the  existence  of  a  distinct  roof  of  the  dinccelia  inde- 
pendent of  the  fornix  and  velum,  which  have  been  removed.  This  diatela  {dtl.)  presents 
the  appearance  of  something  more  than  the  lining  endyma,  but  its  structure  has  not, 
so  far  as  we  know,  been  examined.  The  darker  triangular  area  at  the  cephalic  end  of 
the  diatela  corresponds  with  the  delta  fornicis  (dlt.  /.). 

§  1169.  Fig.  II.— The  Area  cruralis,  with  part  of  the  pons  and  of  the  Ar.  praechi- 
asmatica.     From  Prep's  503,  435  (nearly  adult  ?  )  and  461  ( ^ ) ;    x  1.5. 

This  figure,  reversed,  is  reproduced  in  outline  in  Fig.  118.  The  general  relations  of  the 
medicornu  are  also  indicated  in  Fig.  113,  and  the  relations  of  the  cornu,  rima  and  pro- 
plexus  in  Fig.  121. 

The  Lobi  temporales  have  been  divided  at  different  levels  on  the  two  sides.  From 
the  right,  only  the  extremity,  or  LI.  hypocampm,  has  been  removed,  and  the  section  of  the 
medicornu  (incu.),  which  is  here  cut  very  obliquely,  is  a  slightly  curved  space  completely 
circumscribed  by  a  nervous  wall.  Neither  in  the  cat,  nor — contrary  to  the  common  belief 
and  the  explicit  statement  in  Quain  (A,  II,  542,  544) — in  man,  does  the  rima  or  "great 
transverse  fissure  "  extend  to  the  tip  of  the  medicornu. 

Where  the  LI.  hypocampm  rests  against  the  Tractus  opticus  {Tr.  op.),  there  is  usually 
a  deep  notch  which  may  be  called  the  Incisura  hypocampae  {Inc.  hmp.). 

On  the  left  side,  the  hemisphere  was  dissected  off  so  as  to  leave  two  cut  surfaces.  One 
of  these  surfaces  is  plane  and  nearly  horizontal,  and  lies  at  about  the  level  of  the  dorsal 
end  of  the  postgeniculatum  {pgn.).  The  other  is  convex,  and  extends  from  the  cephalic 
border  of  the  former  obliquely  to  the  ventral  surface  of  the  brain  ;  it  corresponds  closely 
with  the  cephalic  border  of  the  Tractus  opticus. 


468  ANATOMICAL    TECHNOLOGY. 

The  left  medicornu  is  cut  at  about  tlie  middle,  and  at  nearly  a  right  angle  with  its 
course  ;  hence  its  lumen  presents  its  characteristic  crescentic  section,  the  ental  boundary 
being  the  convex  surface  of  the  hypocampa  (Jimp.). 

The  cephalic  margin  of  the  medicornu  is  here  seen  to  reach  the  surface  of  the  hemi- 
sphere close  to  the  Tractus  opticus,  and  this  narrow  line  of  interruption  of  the  true  ner- 
vous wall  of  the  cornu  constitutes  the  rima.  The  scale  upon  which  this  figure  was  drawn 
did  not  permit  the  relations  of  the  pia,  the  velum  and  the  proplexus  to  be  shown,  and  the 
undulations  of  the  ectal  surface,  corresponding  with  the  FF.  hypocampce  and  fimhrloe,  and 
xhefaiciola  emd  fimbria  are  hidden  by  the  projecting  postgeniculatum. 

Most  of  the  cephalic  portion  of  the  brain  has  been  removed,  but  the  Portio  depressa 
(Pt.  d.)  of  the  praeperforatus  is  seen,  with  part  of  the  Pt.  prominens  {Pt.  p.).  The 
removal  of  most  of  the  chiasma  (ch.)  exposes  the  form  and  extent  of  the  Recessus  opticus 
(M.  op.). 

The  pons  has  been  transected  obliquely,  and  its  caudal  portion  removed,  together  with 
the  rest  of  the  epen.  and  the  metencephalon. 

The  left  crus  (Cr.  ch.)  is  seen  in  its  whole  length,  excepting  a  small  part  concealed  by 
the  slightly  projecting  cephalic  border  of  the  pons.  The  well  marked  cimbia  (cmh.)  may 
perhaps  be  regarded  as  the  boundary  between  the  diencephalic  portion  of  the  crus  {Pt. 
dien.)  and  the  mesencephalic  portion  {Pt.  msen.),  which  more  directly  supports  the  optici 
and  postoptici ;  in  man,  this  part  seems  to  be  more  nearly  concealed  by  the  pons. 

The  right  N.  oculomotorius  {N.  ocm.)  is  seen  to  emerge  from  the  crus  just  caudad  of 
the  mesal  end  of  the  cimbia  and  just  laterad  of  the  Sulcus  intercruralis  lateralis  {SI. 
ic.  I.).  A  marked  longitudinal  ridge  of  the  crural  fibers  separates  from  the  2)ostgi^riicu- 
latum  { pgn )  a  depressed  area,  the  quadrans  {q.). 

The  albicantia  {ahn.)  are  more  closely  united  than  in  man,  but  large,  white  and  per- 
fectly distinguishable.  The  shallow  furrow  between  them,  together  with  the  u  shaped 
furrow  which  forms  their  cephalic  boundary,  is  the  Sulcus  triradiatus  {81.  trd.). 

The  hypophysis  has  been  removed  so  as  to  expose  the  Tuber  cinereum  {T.  cin.)  and 
the  thin  raised  margin  of  the  Fm.  infundibuli  {Fin.  inf.). 

Just  caudad  of  the  albicantia,  and  partly  overhung  by  them,  is  a  small  triangular 
depressed  space  with  distinct  perforations  ;    this  seems  to  be  the  true  postperforatus 

The  entire  Area  intercruralis  may  be  more  completely  exposed  by  removing  the  cere- 
bellum and  dorsiducting  the  "medulla,"  as  in  Prep.  435. 

^  1170.  Fig.  12. — The  dorsal  aspect  of  the  metencephalon.  From  Prep.  397 
(adult  9  ),  464  and  491  ;    x  1. 

"  The  metatela,  like  the  diatela,  seems  to  consist  of  more  substantial  tissue  than  sim- 
ply pia  and  endyma,  but  I  am  not  aware  that  its  microscopic  structure  has  been  ascer- 
tained. I  am  in  doubt  respecting  the  precise  limits  and  attachments  of  the  metatela 
and  metaplexuses."     No  "  foramen  of  Magendie  "  was  seen. 

§  1171.  Fig.  13. — Part  of  an  oblique  transection  of  the  prosencephalon  and  dien- 
cephalon  to  show  the  form  and  position  of  the  Crista.     From  Prep.  441  ;    x  3. 

The  brain  was  transected  obliquely  at  an  angle  of  about  45  degrees  with  the  general 
longitudinal  axis.  The  plane  of  section  passed  from  a  point  nearly  dorsad  of  the  genu, 
through  the  aula,  the  medicornu  and  the  albicantia.  The  figure  includes  only  a  part  oi" 
the  caudal  aspect  of  the  slice. 

The  dorsal  borders  of  the  hemispheres  are  divaricated  slightly,  and  the  callosum  (cl  1 
is  seen  crossing  the  interval  ;  the  slight  notch  on  each  side  just  dorsad  of  the  callosr.in  io 
the  F.  callosalis  {F.  cl.\ 


EXPLANATION    OF    THE    PLATES.  469 

The  striata  {s.  s. )  are  seen  in  section  j  ust  ventrad  of  tlie  lateral  expansion  of  the  callo- 
sum,  while  the  lower  part  of  the  figure  is  occupied  by  the  thalami  (th.),  united  by  the 
medicommissura  (mcs.).  Between  each  thalamus  and  the  corresponding  striatum  is  a 
groove,  the  Sulcus  limitans  {SI.  U.). 

The  Columnae  fornicis  {Clm.f.)  are  divided  nearly  at  a  right  angle  with  their  course, 
and  at  a  point  just  dorsad  of  the  crista  (Crs.f.),  which  is  particularly  well  shown  in  this 
preparation.  The  open  space  between  the  fornix  and  the  thalami  is  the  aula  (a.),  and  at 
the  sides  are  the  portae  (p.)  leading  into  the  proccdicB.  All  the  membranes  and  plexuses 
have  been  removed.  , 

PLATE  IV. 

Unlike  those  of  Plate  III,  all  of  the  figures  upon  this  plate  represent  cut  surfaces, 
although  some  natural  surfaces  are  shown  also. 

§  1172.  Fig.  14. — A  ventrocaudal  view  of  the  fornix,  with  the  adjacent  parts. 
From  Prep's  507,  433  and  396  (adult  6);    x  2. 

The  preparations  were  made  while  the  brain  was  fresh,  so  as  to  permit  more  flattening 
of  the  hemispheres,  and  consequent  exposure  of  the  fornix. 

After  the  removal  of  the  rhinen-,  meten-,  epen-  and  mesencephalon,  the  thalami  and 
geniculata  were  excavated  piecemeal,  so  as  not  to  injure  or  displace  the  fornix.  The  cut 
surface  {s )  at  each  side  of  the  fornix  (/.)  is  the  plane  of  division  of  the  diencephalon  from 
the  striatum. 

The  cephalic  end  of  the  prosencephalon  was  then  sliced  down  to  the  level  of  the  prce- 
commismra  (prcs.),  which  is  seen  to  send  a  distinct  fasciculus  toward  the  L.  olfactorius  on 
each  side.  Then  the  right  hemisphere  was  sliced  obliquely  from  near  the  meson  dorso- 
laterad  so  as  to  cut  the  medicornu  {mcu.)  and  hypocampa  (hmp.)  at  about  the  middle  of 
their  length.  On  the  left  side,  the  L.  temporalis  was  allowed  to  fall  somewhat  by  its 
own  weight  so  as  to  expose  the  fornix  more  fully. 

The  velum  and  alltlie  plexuses  were  removed  so  as  to  display  the  peculiar  markings  of 
the  fornix  and  its  raesal  area,  which  is  supposed  to  represent  the  lyra  {Ip.). 

The  portae  (p.)  appear  both  shorter  and  narrower  than  they  really  are,  on  account  of 
the  obliquity  of  their  planes  to  the  line  of  vision.  The  v-shaped  line  called  ripa  (rp.), 
which  connects  the  two  portae,  separates  the  delta  (dlt.)  or  entocoelian  part  of  the  fornix 
from  the  remaining  surface,  which  is  wholly  outside  of  the  coelian  cavity.  The  delta 
forms  the  roof  of  the  aula,  the  cephalic  continuation  of  the  diacoelia  between  the  two 
portse,  and  the  ripa  is  the  line  of  reflection  of  the  endyma  upon  the  two  auliplexuses  ;  the 
removal  of  these  plexuses  causes  the  rupture  of  the  endyma  along  the  ripa. 

At  each  side,  the  ripa  curves  dorsad  somewhat  sharply  so  as  to  reach  the  dorsal  end  of 
the  porta ;  at  this  point,  and  dorso-caudad  for  the  entire  length  of  the  rima  (r.),  the 
endyma  is  simply  reflected  from  the  contiguous  surfaces  of  the  fimbria  {fmh.)  and  the  cor- 
responding border  of  the  striatum.  Hence  the  rima  is  virtually  dosed,  and  thus  wholly 
distinct  from  the  porta. 

On  the  meson,  between  the  portae,  is  seen  the  crista  (Grs.  /.),  which  is  unusually 
rounded  in  this  preparation.  The  carina,  which  sometimes  appears  as  a  slight  mesal  ridge 
extending  dorso-caudad  from  the  crista,  does  not  appear  in  this  preparation.  The  Reces- 
sus  aulae  {R.  a.)  is  the  cleft  between  the  two  Columnae  fornicis  (Clm.f.)  whose  cut  ends 
are  seen  just  caudad  of  the  praecommissura.  The  shading  on  the  caudal  aspect  of  the 
columnae  indicates,  but  rather  too  distinctly,  a  slightly  depressed  area,  of  which  the  dorsal 
part,  close  to  the  crista,  sometimes  presents  the  appearance  of  a  transverse  band,  for  which 
the  senior  author  has  suggested  the  name  Commissur a  fornicis  (Cs.f). 


470  ANATOMICAL    TECHNOLOGY. 

"  After  a  prolonged  examination  of  many  preparations,  I  am  unable  to  define  accurately 
the  limits  of  the  fornix  proper  and  the  lyra  {ly.).  A  comparison  of  the  accounts  given  in 
standard  works  with  the  appearances  presented  by  the  limited  materials  at  my  disposal 
leads  me  to  doubt  whether  the  relative  extent  of  the  two  parts  in  the  human  brain  is 
well  determined." 

The  fasciola  (fi^cl.)  is  thick,  and  no  part  of  it  presents  the  denticulations  from  which 
its  more  ventral  portion,  in  man,  is  called  "  fascia  dentata."  The  peculiar  curve  of  the 
hypocampa,  medicornu  and  fasciola  is  well  indicated  by  the  fact  that  the  F.  hypocampae 
{F.  hmp.),  which  corresponds  nearly  with  them  in  direction,  is  visible  in  this  preparation 
only  at  its  two  ends,  near  the  splenium  {sp.),  and  near  the  tip  of  the  LI.  hypocampae  {LI. 
hmp.).  Between  the  fimbria  and  the  fasciola  is  a  depressed  line  which  may  be  called  the 
Fissura  fimbriae  {F.fmb.). 

%  11T3.    Fig.  15. — The  dorsal  aspect  of  the  procoelia.     From  Prep.  465  ;   x  1. 

The  special  object  of  this  preparation  is  to  show  that,  in  the  cat,  no  part  of  the  thalamus 
appears  in  the  proccelia.     The  cerebellum  (cbl.)  is  shown  only  in  outline. 

Both  hemispheres  were  sliced  from  the  dorsum  to  the  level  of  the  intermediate  part  of 
the  callosum  {d).  This  laid  open  both  procoeliae  in  some  degree.  The  central  part  of 
each  procoelia  is  called  cella  media  {ccl.  m.).  The  right  medicornu  was  then  opened  to 
the  tip,  which,  however,  cannot  be  seen  from  the  dorsal  side. 

The  floor  of  the  proccelia  is  seen  to  be  formed  by  the  striatum  («.),  the  fornix  (/.)  and 
the  hypocampa  (hmp.).  The  proplexuses  have  been  turned  in  opposite  directions  for  the 
sake  of  showing  the  absence  of  any  interval  between  the  fornix  and  hypocampa — or  the 
fimbria  which  forms  the  border  of  the  latter — and  the  striatum,  such  as  would  permit  the 
appearance  of  the  thalamus  in  the  procoelia.     See  Fig.  121. 

§  1174.    Fig.  16. — The  rhinocoelia  and  procoelia.     From  Prep's  425  and  493  ;    x2. 

This  figure  shows  the  continuity  of  the  proccelia  with  the  rhinoccdia  and  its  communica- 
tion through  the  porta  with  the  aula  and  diacodia.     See  §  1151. 

The  right  half  of  the  brain  was  transected  through  the  caudal  part  of  the  medicommis- 
sura  (mcs.).  A  slice  was  then  cut  from  the  mesal  aspect  so  as  to  include  the  genu.  This 
exposed  the  praecornu  (pi'cu,)  with  the  mesal  aspect  of  the  striatum  (*.),  the  rhinocoelia 
(rhc),  and  the  relative  extent  of  the  pes  (ps.),  and  the  pero  (po.)  of  the  Lobus  olfacto- 
rius.  A  bristle  was  then  passed  through  the  porta  from  the  praecornu  into  the  aula  {n.). 
Just  ventrad  of  the  bristle  are  the  praecommissura  (prcs.)  and  the  terma  (t.).  The  latter 
is  traced  distinctly  to  the  chiasma  (ch.),  so  that  the  cephalic  wall  of  the  coelian  cavity  is 
complete.  The  deeper  shadow  just  dorsad  of  the  chiasma  indicates  the  position  of  the 
Recessus  opticus  (R.  op.). 

Just  dorsad  of  the  bristle,  the  crista  {Ors.f)  is  seen  divided  upon  the  meson,  and  con- 
tinuous with  the  Columna  fornicis  (Clm.f).  The  indentation  between  the  crista  and  the 
praecommissura  corresponds  with  the  Recessus  aulas  [R.  a.).  The  triangular  Area  sep- 
talis  {Ar.  sj)t.),  between  the  fornix  and  the  callosum,  is  the  mesal  surface  of  the  right  half 
of  the  Septum  lucidum  {Spt.  lu.)  and  is  in  contact  with  its  platetrope  in  the  undissected 
brain.  The  thickness  of  the  hemisepta  in  the  cat  renders  the  adjective  lucidum  wholly 
inapplicable. 

§  1175.  Fig.  17.— The  mesal  aspect  of  the  right  hemisphere,  with  the  Lobus 
olfactorius.     From  Prep's  296  and  401  ;    x  1. 

The  caudal  divisions  of  a  hemiencephalon  were  removed,  and  the  thalamus  carefully 
excavated  so  as  to  leave  undisturbed  the  fornix  (/.)  and  the  fimbria  {fmb.).  In  this 
respect,  this  figure  may  be  compared  with  the  left  half  of  Fig.  14. 


r 


^'  SFNONYJIS    AND    REFERENCES,  471 

The  special  object  of  this  figure  is  to  show  the  hypocampal  fissure  {F.  hmp,)  in  its 
whole  length  at  once.  So  great  is  the  curvature  of  the  parts  that  this  is  possible  only  in 
a  single  i)osition  of  the  preparation  in  which  tlie  meson  is  foreshortened.  In  general,  this 
figure  may  be  compared  with  those  given  by  Flower  (113)  of  the  rabbit  and  sheep. 

The  dorsal  end  of  the  F.  hypocampce  is  seen  to  turn  sharply  around  the  splenium  {sp.)l 
so  as  to  become  continuous  with  the  callosalis  {F.  cl.).  The  fasciola  {fscD  is  wide  and 
devoid  of  denticulatious,  but  is  crossed  obliquely  by  a  shallow  furrow.  In  this  position  of 
the  preparation,  the  F.  fimbriae  {F.fmb.)  appears  to  be  continuous  with  a  short  line  pass- 
ing cephalad  to  a  point  ventrad  of  the  callosum  ;  in  reality,  however,  this  latter  line  is 
only  one  of  the  markings  of  the  ventral  surface  of  the  fornix,  and  the  F.  fiiribrice,  like  the 
callosalis,  turns  sharply  dorso-caudad  to  terminate  just  cephalad  of  the  splenium  (Fig.  125). 

g  1176.  Fig.  i8. — The  right  proccElia  seen  from  the  right  or  ectal  side.  From 
Prep,  495;    x  1. 

The  right  half  of  the  brain  was  removed  in  successive  slices  until  what  remained  was 
about  3  mm.  thick.  The  remainder  of  the  striatum  was  then  everted  from  the  praecornu 
(prcu.).  The  proplexus  {prpx.)  is  slightly  displaced,  but  the  porta  is  hidden  by  the 
portiplexus  (ppx.).  The  medicornu  {men.)  and  the  hypocampa  (hmp.)  are  shown  in  sec- 
tion, and  the  other  parts  will  be  readily  recognized.  The  relative  heights  of  the  opticus 
iop.)  and  the  postopticus  (pop.),  at  a  little  distance  from  the  meson,  are  well  displayed. 
The  short  curved  line  at  the  cephalo- ventral  end  of  the  procoelia  represents  the  beginning 
of  the  passage  to  the  rhinocoelia  (Fig.  16). 

§  1177.  Fig.  19. — The  left  praecornu  and  porta  exposed  from  the  left  or  ectal  side. 
From  Prep.  495  ;    x  1. 

This  figure  represents  the  other  side  of  the  same  brain  from  which  Fig.  18  was  drawn. 
The  preparation  was  made  in  the  same  way,  but  in  addition  the  proplexus  and  porti- 
plexus were  carefully  snipped  off  so  as  to  expose  the  porta. 

The  porta  (2>)  is  seen  to  open  between  the  Columna  fornicis  {Clm.  /.)  and  the  cephalic 
end  of  the  thalamus  (^A.).  The  orifice  would  appear  larger  if  the  preparation  had  been 
so  placed  as  to  leave  its  plane  parallel  with  the  picture-plane. 

The  membranes  could  not  be  shown  well  on  so  small  a  scale  (see  Fig.  123).  In  this 
and  in  the  previous  figure,  the  fornix  is  seen  to  be  continuous  with  the  hemiseptum  {&pt. 
III.)  which  forms  part  of  the  mesal  wall  of  the  pracornu. 

§  1178.    Fig.  20. — Transection  of  the  fornix  with  the  crista.    From  Prep.  508  ;  x  1. 
The  object  of  this  figure  is  to  show  the  decided  elevation  formed  by  the  crista  {Grs.  /.). 
Only  enough  of  the  rest  of  the  section  is  included  to  locate  the  crista. 

§  1179.  Other  Figures  of  the  Cat's  Brain.— Since  most  published  figures  of  the  cat's 
brain  illustrate  the  fissures  rather  than  the  structure,  they  will  be  mentioned  in  connec- 
tion with  Fig.  124,  125,  later  in  this  chapter. 

SYNONYMS  AND  REFERENCES. 

§  1180.  The  principal  parts  of  the  Amphibian  brain  are  enume- 
rated in  §  1058  and  tabulated  according  to  their  segments  in  §  1069. 

Most  of  the  parts  of  the  Mammalian  brain  which  are  visible  to 
the  unaided  eye  are  named  in  §  1128  in  the  alphabetical  order  of 
their  abbreviations,  and  in  §  1138  they  are  tabulated  according  to 


472  A  XA  TOMICAL     TECHS  OL  0  G  Y. 

their  segments.  Synonyms  of  about  twenty  of  the  principal  parts 
are  given  in  §§  1058,  1059. 

In  the  following  pages  (§§  1181-1333)  the  parts  of  the  mammalian 
brain  are  enumerated  in  the  alphabetical  order  of  the  technical 
names  herein  employed.  Unless  otherwise  mentioned,  these  names 
are  the  same  as  adopted  by  the  senior  author  {9,  14) ;  the  ap- 
parently new  terms  really  differ  but  little  from  those  in  common 
use  (§  1129). 

Following  the  abbreviation  of  each  name  are  references  to  figures 
and  sections  in  the  present  work  and  to  the  works  on  Human  Anat- 
omy by  Gray  and  Quain.  The  principal  technical  and  English 
vernacular  synonyms  are  then  given,  with  in  most  cases  a  brief 
description  or  commentary  upon  the  part  itself  or  its  designation. 

As  has  been  stated  already,  our  information  is  far  from  satisfac- 
tory, and  all  parts  of  the  cat's  brain  need  monographic  treatment. 

§  1181.  Alba,  (Substantia),  alb.—%%  995,  1047  ;  Fig.  112,  116  ;  PL  III.  Fig.  13  ;  PI.  IV, 
Fig.  14.     Gray,  A,  60 ;  Quain,  A,  II,  553. 

Si/n. — Substantia  alba,  white  matter,  white  or  fibrous  nervous  tissue. 

The  alba  constitutes  the  columns  of  the  myelon,  most  of  the  ental  portions  of  the  cere- 
brum and  cerebellum,  and  so  much  of  the  entire  brain  as  is  not  formed  by  the  cinerea, 
which  see,  §  1204. 

§  1182.  Albicans,  (Corpus),  ahn.—Fig.  115,  116 ;  PI.  II,  Fig.  3,  4 ;  PI.  Ill,  Fig.  11 ; 
§  1161.     Gray,  A,  621  ;  Quain,  A,  II,  535. 

8yn. — Corpus  caudicans,  corpus  mammillare,  bulbus  fornicis. 

The  albicantia  are  a  pair  of  white  elevations  a  little  cephalad  of  ilae  pons  and  overhang 
ing  the  postperforatus.  They  are  distinct,  but  less  so  than  in  man.  For  their  relation 
to  the  Columnae  fornicis,  see  §  1207. 

§  1183.  Arachnoidea,  (Membrana),  arch.—Yi^  112,  H  ;  §  1077.  Gray,  A,  608  ;  Quain, 
A,  II,  519  ;  V^estbrook,  1,  348. 

8yn. — Arachnoideus,  meninx  media,  tunica  serosa. 

Like  the  pia,  this  membrane  needs  thorough  examination  in  the  cat. 

§  1184.  Arbor  vitae,  arh.  vt.—F\g.  88,  117;  PI.  II,  Fig.  4.  Gray,  A,  634;  Quain,  A, 
II,  519. 

The  ectal  foliation  of  the  cerebellum  gives  to  the  surface  of  a  dorso-ventral  section  a 
tree -like  appearance,  to  which  the  above  name  is  applied. 

^  1185.   Aula  {az.),  «.— Fig.  110-112  ;  PI.  II,  Fig.  4  ;  PI.  Ill,  Fig.  13  ;  PI.  IV,  Fig.  16 
g§  1065,  1145.     Meynert  (Strieker,  A,  Fig.  253) ;  Balfour,  A,  II,  Fig.  257. 

Syn. — "  Le  vestibule  des  ventricules  lateraux  " — Milne-Edwards,  A,  XI,  305. 

Cavity  of  the  prosencephalon  primitivum— Mihalkovics,  A,  30. 

Cavity  of  the  "  secundares  vorderhirnblaschen  " — Mihalkovics,  A,  PI.  1,  Fig.  1. 

Cavity  of  the  "  unpaaren  grosshirnblase  " — Lowe,  A,  93,  Fig.  11,  12,  "  es.'' 

Mesal  portion  of  the  cavity  of  the  "  lobus  communis  " — Huxley,  1,  00. 

Mesal  portion  of  "  Foramen  commune  anterius  "—Todd,  A,  676 ;  Quain,  A,  II,  544, 
and  other  writers,  according  to  Bell,  B,  PI.  X, 

"  Iter  ad  tertium  ventriculum  " — Monro,  A,  9. 


srxoyY3is  and  references.  473 


r 

■  "  Rima  ad  inf  andibuli,  s.  vuWa  " — Various  authors,  according  to  Dunglison,  A,  906. 
B  Mesal  portion  of  the  foramen  of  Monro — Balfour,  A,  II,  257. 

■  Mesal  portion  of  the  "  ventriculus  communis  " — Stieda,  22,  453. 

■  Mesal  portion  of  the  "  common  ventricular  cavity  " — Spitzka,  (i,  31. 

^  The  aula  is  the  most  cephalic  part  of  what  is  commonly  known  as  the  third  ventricle. 

Its  l)est  defined  portion  lies  between  the  two  portae,  and  is  bounded  cephalad  by  the  fornix 
and  caudad  by  the  medicommissura.  Ventrad  it  reaches  the  chiasma  so  as  to  include  the 
Recessus  optici ;  dorsad  it  is  bounded  by  the  triangular  area  of  the  fornix,  called  delta. 
The  form  of  the  cavity  is  therefore  peculiar  and  irregular. 

The  Name. — The  origin  of  the  name  and  the  reasons  for  its  use  are  briefly  stated  in 
§  1065.  Much  remains  to  be  done,  especially  in  Comparative  Anatomy  and  Embryology, 
before  the  limits  of  this  cavity  can  be  well  defined. 

§  1186.    Auliplexus,  apx.—Yxg.  113  ;  §  1066. 

The  aulic  portion  of  the  "  plexus  choroideus  ventriculi  tertii  '^  or  diaplexus. 

This  portion  of  the  plexus  is  so  slight  that  it  would  hardly  need  a  separate  designation 
but  for  the  possibility  that  in  the  cat,  as  in  Menobranchus,  the  larger  diaplexus  may  be 
only  an  extension  of  the  more  primitive  auliplexus. 

§  1187.  Area  cruralis  {az\  Ar.  cr.— Fig.  116, 118  ;  PI.  II,  Fig.  3 ;  PI.  Ill,  Fig.  11. 

A  convenient  name  for  the  ill-defined  and  non-homogeneous  area  of  the  basis  encephali 
bounded  by  lines  projected  laterad  from  the  pons  and  chiasma.  See  Area  intercruralis 
{%  1189). 

§  1188.   Area  elliptica,  Ar.  el.—¥\g.  116  ;  PI.  II,  Fig,  3  ;  §  1140. 

According  to  the  Am.  Jour,  of  Neurology,  etc.  (I,  102),  this  is  the  surface  of  the  olica, 
notwithstanding  the  funiculi  of  the  N.  hypoglossus  emerge  laterad  of  it  instead  of  mesad 
as  in  man. 

§  1189.  Area  intercruralis  {az),  Ar.  icr.—F\g.  116,  118  ;  PI.  II,  Fig.  3  ;  PI.  Ill,  Fig. 
U;  §1133. 

8yn. — Interpeduncular  space  ;  Area  intercruralis  (manuscript) — Spitzka,  7,  165. 

If  the  diverging  fibrous  tracts  sometimes  called  peduncuU  cerebri  are  to  be  called  crura, 
then  the  space  bounded  by  them  and  by  the  pons  and  chiasma,  should  be  intercrural 
rather  than  interpeduncular, 

§  1190.   Area  ovalis,  Ar.  ov.—Fig.  116  ;  PI.  II,  Fig.  3  ;  §  1140. 

The  surface  of  an  elevation  of  the  ventro-lateral  aspect  of  the  metencephalon,  laterad 
of  the  Area  elliptica. 

According  to  the  Am.  Jour,  of  Neurology,  etc.  (I,  102),  this  corresponds  with  the  Tuber- 
cle of  Rolando,  "  tiibercolo  cinereo." 

%  1191.    Area  postpontilis  (az.),  Ar.  ppn.—Fig.  116 ;  PI.  II,  Fig.  3  ;  §  1133. 

The  ventral  aspect  of  the  metencephalon.  It  includes  the  Area  elliptica,  the  Ar.  ovalis, 
the  pyramis  and  trapezium,  and  the  ectal  origins  of  several  nerves. 

§  1192.   Area  praechiasmatica  {az.),  Ar.  prch.— Fig.  116  ;  PI.  II,  Fig.  3. 

The  ventral  aspect  of  the  basis  encephali  cephalad  of  the  chiasma. 

§  1193.   Ar.  septalis,  Ar.  spt.—  F\g.  117;  PI.  II,  Fig.  4;  PI.  IV,  Fig.  16. 

The  mesal  surface  of  either  half  of  the  Septum  lucidum  ;  see  pseudocoelia,  %  1297. 

Septal  area — Flower,  13,  634.     The  name  is  ascribed  to  Huxley. 

§  1194.   Calcar  (avis),  c^c— Gray,  A,  625 ;  Quain,  A,  II,  542. 

This  is  the  brief  synonym  of  hippocampus  minor,  ergot  and  unciform  eminence.  It  des- 
ignates a  projection  into  the  postcornu  of  man  and  monkeys,  and  has  not  been  observed  iu 
the  cat,  where  the  postcornu  is  not  normally  developed. 


474  ANATOMICAL    TECHNOLOGT. 

§  1195.  Callosum  {az,\  c^.— Fig.  88,  104,  115,  117,  122,  125;  PI.  II,  Fig  4;  PI.  Ill, 
Fig!  13 ;  PI.  IV,  Fig.  15-17,  20.     Gray,  A,  623;  Quain,  A,  II,  537. 

Byn, — Corpus  callosum,  commissura  magna,  trabs  cerebri, 

A  broad  band  of  nerve  fibers  connecting  the  mesal  surfaces  of  the  hemispheres  along  a 
line  dorsad  of  the  fornix  and  curved  ventrad  at  each  end.  The  cephalic  curvature  is  the 
genu  and  the  caudal  the  splenium. 

In  nearly  its  caudal  half,  the  callosum  is  in  contact  with  the  fornix  at  the  meson  and 
for  1-2  mm.  laterad  (Fig.  122,  §  1149).  With  care  the  callosum  may  be  dissected  up  from 
the  fornix,  and  at  the  splenium  the  two  are  then  seen  to  be  continuous.  In  fact,  a  simple 
way  of  describing  their  relati(ms  is  the  following  : — 

The  two  hemispheres,  originally  separate,  become  united  along  two  lines  represented 
by  the  callosum  and  the  fornix.  The  former  is  approximately  straight,  excepting  at  its 
ends,  the  cephalic  corresponding  with  the  genu  and  rostrum.  The  latter  forms  the  seg- 
ment of  a  circle,  but  the  caudal  end  turns  dorsad  to  become  continuous  with  the  caudal 
end  of  the  callosal  line  which  is  curved  ventrad  at  the  splenium. 

The  fibers  constituting  the  larger  part  of  the  callosum  pass  dorsad  of  the  procmlia  and 
thus  constitute  its  roof ;  the  fibers  of  the  fornix  pass  ventrad  of  the  procoelia  and  thus 
enter  into  the  composition  of  its  floor  ;  the  fibers  of  the  splenium  are  intermediate,  and  are 
partly  continued  into  the  hypocampa  and  partly  into  the  general  caudal  part  of  the  hemi- 
sphere.    These  relations  are  indicated  in  PI.  IV,  Fig.  19,  20. 

Notwithstanding  the  fact  that  the  callosum  exists  only  in  mammals,  is  larger,  as  a 
rule,  in  the  higher  members  of  the  group,  and  presumptively  has  great  physiological 
importance,  there  are  recorded  several  cases  of  its  more  or  less  complete  absence  from  man, 
once  without  serious  lack  of  mental  or  physical  power  (Malinverni  [Henry,  7]) ;  and  the 
senior  author  has  reported  {13)  a  case  of  its  complete  absence  in  a  cat  wliich  is  not 
known  to  have  been  peculiar  during  life. 

§  1196.  Canalis  centralis  (myelonis),  {az.\  Gn.  ce.— Fig.  99,  100,  109, 113, 117;  PI.  II, 
Fig.  4     Gray,  A,  68  ;  Quain,  A,  I^,  500. 

The  central  canal  of  the  *'  cord." 

The  mesal  canal  of  the  myelon,  which  expands  cephalad  and  is  opened  up  into  the  dor- 
simesal  fissure  so  as  to  form  the  metacodia.  In  the  cat  this  canal  persists  through  life,  but 
in  man  it  is  said  to  be  commonly  obliterated  in  the  adult,  excepting  at  the  cephalic  end. 

§  1197.  Carina  (ctz.),  ca. — This  is  a  mesal  ridge  upon  the  ventro-caudal  aspect  of  the 
fornix,  extending  from  the  crista  the  entire  length  of  the  delta.  It  varies  in  distinctness 
and  does  not  appear  upon  any  of  the  preparations  here  figured,  but  is  very  well  marked 
in  Prep.  530,  M.  C.  U. 

g  1193.  Cauda  striati,  c(?.  s.— This  is  not  distinctly  shown  in  the  figures  and  has  not 
been  accurately  observed  by  us. 

The  sbnder  tail-like  prolongation  of  the  striatum. 

Former  writers  who  mentioned  this  portion  of  the  striatum  (Todd,  Gratiolet,  Hirsch- 
feld,  and  C'uvier,  B,  III,  51)  gave  it  no  special  name.  Recently  it  has  been  described  by 
Dalton  {1,  12)  under  the  name  of  surcingle.  Having  vainly  requested  him  to  substitute 
for  this  vernacular  term  some  equivalent  technical  one,  the  senior  author  reluctantly  pro- 
posed {0,  134)  the  name  here  employed,  which  is  approved  by  Spitzka,  7,  165. 

§  1199.  Cella  media,  eel.  m.—V\.  IV,  Fig.  15  ;  §  1147.  Gray,  A,  625  ;  Quain,  A, 
II,  540. 

The  central  or  intermediate  portion  of  the  procxlia  ;  its  limits  are  not  defined. 

§  1200.  Cerebellum  {az.\  c&^.— Fig.  88,  104,  113-117;  Pi.  I,  Fig.  1,  2;  PI.  II,  Fig. 
3,  4  ;  PI.  IV,  Fig.  15  ;  §  1074  (C).     Gray,  A,  032  ;  Quain,  A,  II,  515. 

Syn. — Cerebrum  parvum. 


SYNONYMS    AND    REFERENCES.  .  475 

Next  to  the  cerebrum,  the  largest  portion  of  the  brain.  A  single  foliated  mass,  form- 
ing with  the  valvula  the  dorsal  part  of  the  epencephalon  and  constituting  the  roof  of  part 
of  the  epicoelia. 

§  1301.  Cerebrum  (az.),  cb.—Fig.  88,  104,  113-117,  124,  125  ;  PI.  I,  Fig.  1,  2  ;  PI.  II, 
Fig.  3,  4 ;  PL  III,  Fig.  5.  6.  13  ;  PI.  IV,  Fig.  14-20.     Gray,  A,  615 ;  Quain,  A,  II,  522. 

S^n. — Prosencephalon,  hemisphserae. 

The  largest  portion  of  the  brain,  forming  two  convoluted  lobes  between  the  Lobi  olfac- 
torii  and  the  thalami ;  the  former  are  partly,  the  latter  wholly,  covered  by  them.  The 
striata  and  JiypocampcE  are  thickenings  of  certain  parts. 

The  thalami  and  optici  are  not  properly  "  internal  parts  of  the  cerebrum." 

§  1202.  Chiasma  {az.\  c^.— Fig.  116-118 ;  PI.  II,  Fig.  3,  4;  PI.  Ill,  Fig.  5,  11 ;  PL  IV, 
Fig.  16.     Gray,  A,  621,  639 ;  Quain,  A,  II,  536. 

Syn. — Chiasma  nervorum  opticorum,  optic  commissure. 

The  subcylindrical  x-shaped  mass  at  the  base  of  the  brain  formed  by  the  union  and 
decussation  of  the  two  optic  tracts  ;  from  it  the  NN.  optici  pass  to  the  eyes. 

Remark  — We  arc  not  aware  that  special  observations  have  determined  the  extent  of 
the  crossing  or  decussation  of  the  fibers  at  the  chiasma  in  the  cat  ;  the  precise  arrange- 
ment seems  not  to  have  been  determined  for  man  (Meynert  [Strieker,  A,  688 j ;  Ferrier, 
A,  72  ;  Wadsworth,  1,  528). 

§  1203.    Cimbia,  cm?).— Fig.  116,  118  ;  PL  II,  Fig.  3 ;  PL  III,  Fig.  9, 11  ;  §  1142. 

Syn. — Tractus  transversus  pedunculi — Gudden,  as  quoted  by  Meynert  (Strieker,  A,  737). 

A  fibrous  band  crossing  the  Cms  cerebri  just  cephalad  of  the  octal  origin  of  the  N.  ocu- 
lomotorias.  It  may  be  traced  from  between  the  opticus  and  the  postgeniculatum  to  near 
the  ventrimeson,  where  it  suddenly  enters  the  crus. 

The  senior  author  has  suggested  {14:,  554)  that  the  cimbia  may  be  regarded  as  indicat- 
ing the  line  of  junction  bi'tween  the  mesencephalic  and  diencephalic  portions  of  the  crus. 
The  name  was  proposed  as  a  brief  substitute  for  Gudden's  descriptive  term  ;  it  signifies  in 
architecture  a  band  or  fillet  about  a  column. 

§  1204  Cinerea,  (Substantia),  cm.-PL  III,  Fig.  13;  PL  IV,  Fig.  14,15,20;  §995. 
Gray,  A,  622  ;  Quain,  A.  II,  558  ;  Meynert  (Strieker,  A,  651). 

Syn. — Gray  matter,  ganglionic  or  cellular  nervous  tissue,  vesicular  neurine. 

The  myelonal  cinerea  has  been  mentioned  in  §  998.  The  encephalic  cinerea  is  arranged 
by  Meynert  (Strieker,  A,  651)  in  four  categories  :  cortex  cerebri ;  basal  ganglia  [striata  and 
thalami]  ;  central  tabular  gray  [lining  the  coelise]  ;  cerebellar  cinerea.  The  central  tubular 
gray  is  the  subject  of  a  paper  by  Spitzka  {!). 

§  1205.    Clava,  do.— PL  III,  Fig.  12.     Gray,  A,  612  ;  Quain,  A,  II,  505. 

Syn. — Processus  clavatus,  funiculus  gracilis,  pyramis  posterior. 

The  slender  fibrous  band  forming  the  margin  of  the  metacoelia.  It  is  the  cephalic  con- 
tinuation of  the  slender  "  posterior  median  column  "  of  the  myelon. 

The  name  is  used  in  accordance  with  the  remark  of  Spitzka  (7,  165).  We  have  not 
encountered  it  elsewhere. 

§  1208.  Columna  dorsalis  (myelonis\  Clm.  d— Fig.  112  ;  PL  I,  Fig.  1 ;  PL  II,  Fig.  12. 
Gray,  A,  605  ;  Quain,  A,  II,  494. 

Syn. — Columna  posterior,  the  "  posterior  white  column  of  the  cord." 

Excepting  in  Fig.  112,  no  distinction  is  indicated  between  the  larger  Clm.  dorsalis  and 
the  smaller  and  more  mesal  "posterior  median  column,"  which  is  commonly  regarded  as 
merely  a  part  thereof,  and  is  continued  as  the  clava. 

i,  1207.  Columna  fornicis,  Clm.  /.—Fig.  113,  117,  123  ;  PL  II,  Fig.  4  ;  PL  III,  Fig. 
13  ;  PL  IV,  Fig.  14,  16,  20 ;  §  1145.    Gray,  A,  628 ;  Quain,  A,  II,  543. 


476  ANATOMICAL    TECHNOLOGY. 

Syri. — Crus  fornicis  anterius,  anterior  pillar  of  tlie  fornix. 

The  fibrous  fasciculus  vvliich  forms  the  cephalic  boundary  of  the  porta,  extends  ventrad 
to  the  albicans  and  dorso-caudad  as  the  lateral  half  of  the  body  of  the  fornix.  The  colurana 
is  a  difl'erentiated  part  of  the  embryonic  terma  and  is  continuous  with  the  hemiseptum. 

The  two  columnae  are  separated  by  the  Becessus  aulce  and  conjoined  by  the  Commissura 
fornicis. 

§  1208.  Columna  lateralis  (myelonis),  Clm.  l.—Fig.  104,  112  ;  PI.  I,  Fig.  1,  2  ;  PI.  II, 
Fig.  3.     Gray,  A,  605  ;  Quain,  A,  II,  494. 

The  lateral  white  column  of  the  "  cord." 

§  1209.  Columna  ventralis  (myelonis),  Clm.  v.— Fig.  112  ;  116  ;  PI.  II,  Fig.  3  Gray, 
A.  605  ;  Quain,  A,  II,  494. 

The  "  anterior  white  column  of  the  cord." 

§  1210.    Commissura  fornicis  (az.),  Cs.f.—F\.  IV,  Fig.  14. 

This  name  was  provisionally  applied  by  the  senior  author  {14,  543)  to  what  appears  in 
some  preparations  to  be  a  transverse  band  just  ventrad  of  the  crista  fornicis. 

§  1211.  Commissura  habenarum  {az.),  Cs.  h.—Fig.  117  ;  PI.  II,  Fig.  4 ;  Pi.  Ill, 
Fig.  6  ;  §  1143. 

A  narrow  band  of  apparently  nervous  tissue  connecting  the  caudal  ends  of  the  liabenae 
and  constituting  the  cephalic  boundary  of  the  Foramen  conarii 

§  1212.  Conarium  {az.\  cn.—F\g.  Ill,  112,  114,  117;  PI.  II,  Fig.  4 ;  PI.  Ill,  Fig.  ?, 
10  ;  §§  1084,  1143.     Gray,  A,  630  ;  Quain,  A,  II,  549. 

Syn. — Glandula  pinealis,  epiphysis  cerebri. 

A  suborlobular  mass  forming:  a  part  of  the  roof  of  the  diaccelia  just  cephalad  of  the 
postcommissura.  There  is  no  good  evidence  of  its  true  nervous  structure,  and  its  functions 
are  unknown. 

§  1213.  Cortex,  ctx.—Fig.  123  ;  PI.  II,  Fig.  4  ;  PI.  Ill,  Fig.  13  ;  PI.  IV,  Fig.  15,  20  ; 
§  1147.     Gray,  A,  623  ;  Quain,  A,  II,  521,  559. 

The  ectal  cinerea  of  the  cerebrum  or  cerebellum,  more  commonly  of  the  form.er.  It 
consists  of  several  more  or  less  distinct  layers,  whose  structure  and  relations  are  figured 
and  described  by  Meynert  (Strieker,  A,  660)  and  Bevan  Lewis  {1,  88). 

§  1214.  Crista  fornicis  {az.),  Crs.f-Fig.  117 ;  PI.  II,  Fig.  4  ;  PL  III,  Fig.  13  ;  PI.  IV, 
Fig.  14,  16,  20. 

A  hemispherical  or  semioval  elevation  of  the  caudal  surface  of  the  fornix  just  dorsad  of 
the  Recessus  aulae,  between  the  port'3B  and  opposite  the  cephalic  convexity  of  the  medi- 
commissura.     It  is  continued  dorso-caudad  as  the  carina. 

The  crista  seems  not  to  have  been  observed  prior  to  the  senior  author's  paper  (7).  He 
has  observed  it  in  the  brains  of  a  sheep  and  human  subject,  but  has  not  looked  further  for 
it.  Probably  it  will  be  found  in  most  if  not  all  mammals.  Its  histological  composition, 
function  and  morphological  significance  are  unknown.  We  can  only  surmise  that  it  may 
mark  the  dorsal  limit  of  the  primitive  terma. 

§  1215.  Crus  cerebri,  Or.  cb.—Fig.  Ill,  112,  116-118;  PI.  II,  Fig.  3,  4  ;  PI.  Ill,  Fig. 
9.11. 

Syn. — Pedunculus  cerebri,  caudex  cerebri,  crus  anterius  medullae  oblongatae. 

The  fibrous  mass  forming  -with  its  fellow  the  support  of  the  mesencephalon  and  dien- 
cepha^on,  and  extending  from  the  pons  to  the  chiasm  a. 

§  1216.  Crus  olfactorium,  Or.  ol.—Fig.  116,  117,  124,  125  ;  PI.  II,  Fig.  3,  4  ;  PI.  Ill, 
Fig.  5  ;  §  1139.     Gray,  A,  620,  637  ;  Quain,  A,  II,  566. 

&yn. — Crus  rhinencephali,  Owen,  A,  I,  298 ;  olfactory  nerve  or  tract,  Quain,  A,  II, 
'  566  ;  Gray,  A,  638. 


sryoxYjrs  and  references.  477 

The  contracted  portion  of  the  brain  batween  the  prosencephalon  and  the  Lobus  olfac- 
torius.     Its  ventral  surface  is  continuoas  caudad  with  the  Tractus  rhinalis. 

g  1217.    Delta  (fornicis),  {az.),  dlt.—¥\g.  120 ;  PI.  IV,  Fig.  14. 

The  triangular  entocixliaii  area  of  the  ventro-caudal  surface  of  the  fornix,  constituting 
the  roof  of  the  avia.  Its  base  coincides  with  a  line  between  the  portae,  and  its  two  other 
sides  are  ripce,  lines  of  reflection  of  the  endyma  upon  the  intruded  auliplexus.  It  does  not 
appear  to  have  been  observed  prior  to  the  senior  author's  paper  (,9). 

§  1218.  Diaccelia  {az,),  dc—Fig.  110-113,  117,  120,  123  ;  PI.  II,  Fig.  4;  PI.  Ill,  Fig.  7; 
PI.  IV,  Fig.  16 ;  i^  1143.     Gray,  A,  629  ;  Quain,  A,  II,  546. 

Si/n. — Ventriculus  tertius,  third  ventricle,  middle  ventricle,  medi ventricle. 

The  irregular  mesal  cavity  between  the  thalami,  bounded  dorsad  by  the  diatela,  post- 
commissura  and  conarium ;  ventrad  by  the  diencephalic  portion  of  the  Crura  cerebri,  the 
albicantia.  Tuber  cinereura  and  terraa  (reinforced  by  the  chiasma),  continuous  cephalad 
with  the  aula  and  caudad  with  the  mesocoelia.  Most  of  its  dorsal  portion  is  occupied  by 
the  niedicommissura.  Tlie  diacoelia  represents  the  cavity  of  the  primitive  "  anterior  cere- 
bral vesicle." 

The  reasons  for  adopting  this  and  the  other  names  for  the  encephalic  cavities  are  stated 
in  §  1064  and  the  papers  there  referred  to. 

§  1219.  Diaplexus,  dpx.—Fig.  112,  113,  117,  122;  PI.  II,  Fig.  4;  PI.  IV,  Fig,  16; 
i>  1143.     Gray,  A,  628 ;  Quain,  A,  II,  545. 

Si/ii. — Plexus  choroideus  v^ntriculi  tertii,  plexus  choroideus  medius. 

The  string-like  vascular  plexus  extending  the  entire  length  of  the  diaccelia  on  each 
Hide ;  it  is  slightly  attached  to  the  diatela  and  has  firmer  connections  by  vessels  at  its 
ends,  which  are  not  clear  to  us.  It  is  continuous  cephalad  with  the  auliplexus.  For  the 
name,  see  §  1066. 

§  1220.    Diatela  {az.),  dtl—Fig.  111-113,  117,  122;  PI.  Ill,  Fig.  10.     Reichert,  A,  155. 

The  membranous  or  atrophied  nervous  roof  of  the  diacoelia.  Its  exact  composition  has 
not  been  ascertained,  but  it  seems  to  consist  of  something  more  substantial  than  endyma. 
Judging  from  current  statements  respecting  the  roof  of  the  "  third  ventricle,"  this  delicate 
tela  is  usually  torn  oflf  with  the  fornix,  and  no  notice  is  taken  of  the  ragged  lines  of  its 
se[)aration  along  the  Sulcus  habence  on  each  side.  In  the  Museum  of  Cornell  University, 
however,  there  are  preparations  of  the  cat  and  rabbit  which  show  the  diatela  after  the 
removal  of  the  fornix  and  velum,  while  the  ripw  or  lines  of  reflection  are  apparent  upon 
many  others,  as  in  that  shown  in  PI.  Ill,  Fig.  7. 

^  1221.  Diencephalon  {az.),  den.— Fig.  88,  110-113,  116-118,  122;  PI.  II,  Fig.  3,  4; 
PI.' Ill,  Fig.  6,  7,  9-11 ;  PI.  IV,  Fig.  16,  18,  19 ;  §  1061.     Gray,  A,  111  ;  Quain,  A,  II,  755. 

Syn. — Deutencephalon,  thalamencephalon,  interbrain,  'tweenbrain. 

The  encephalic  segment  between  the  mesencephalon  and  the  prosencephalon.  Its 
cavity  is  the  diacoelia  ("  third  ventricle  "),  and  its  chief  constituents  are  the  tJialami. 

%  1222.    Dura  (mater),  d.—F\g.  88;  §  1104.     Gray,  A,  606;  Quain,  A,  II,  569. 

The  firm  membrane  which  lines  the  cranial  cavity,  is  reflected  upon  the  osseous  tento- 
rium (§  552),  and  is  produced  between  the  hemispheres  as  the  falx  cerebri  ;  it  is  an  en  to- 
cranial  periosteum. 

Notwithstanding  its  feminine  form,  dura  is  frequently  employed  without  the  substan- 
tive mater. 

%  1223.    Eminentia  auditoria,  Em.  au.^F].  I,  Fig.  2;  PI.  II.  Fig.  3  ;  §  1140. 

The  name  was  suggested  by  the  senior  author  {14,  536)  for  the  distinct  elevation  just 
laterad  of  the  trapezium,  whence  springs  the  JSF.  auditor ius.  It  is  continuous  mesad  with 
a  Tractus  auditorius,  which  does  not  appear  in  the  figures. 


478  ANATOMICAL    TECHNOLOGY. 

§  1224.  Endyma,  ewe?.— Fig.  Ill,  112,  121-123  ;  §  1079.  Gray,  A,  630 ;  Quain,  A, 
II,  540. 

Syn. — Ependyma,  pia  mater  interior.  

The  epithelial  lining  of  the  coelise,  which  is  reflected  upon  the  plexuses. 

§  1235.  Epencephalon  (as.),  epen.—Fig.  88,  104,  110-114,  117;  PI.  I,  Fig.  1,  2;  PI.  II, 
Fig.  3,  4;  PI.  Ill,  Fig.  12  ;  PI.  IV,  Fig.  15.     Gray,  A,  111  ;  Quain,  A,  II,  755. 

The  encephalic  segment  including  the  cerebellum,  pons,  pedunculi,  valvula,  and  the  cor- 
responding part  of  the  "  medulla." 

While  it  is  convenient  to  recognize  the  segment,  its  precise  limits  are  difficult  to 
assign,  and  Spitzka  (7,  165)  inclines  to  abandon  the  segmental  name  altogether.  If  the 
caudal  boundary  coincides  with  the  margin  of  the  pons,  the  trapezium  of  man  will  be 
included  therewith,  while  that  of  the  cat  remains  in  the  meteucephalon. 

§  1226,  EpiccElia  (as.),  epc.—Fig.  110-113,  117  ;  PI.  II,  Fig.  4 ;  §  1141.  Gray,  A,  635  ; 
Quain,  A,  II,  512. 

Si/n. — Ventriculus  quartus  or  fourth  ventricle,  the  cephalic  part  ;  ventriculus  cerebelli. 
The  cavity  of  the  epencephalon,  covered  by  the  cerebellum  and  valvula. 

§  1237.  Fasciola,  fscL—Fig.  121 ;  PI.  IV,  Fig.  14,  17.  Gray,  A,  627  ;  Quain,  A^ 
II,  545. 

Syn. — Fascia  dentata,  fasciola  cinerea. 

The  somewhat  thickened  margin  of  cinerea  along  the  fimbria.  In  man  the  ventral 
portion  has  commonly  been  called  fascia  dentata  ;  in  the  cat,  however,  there  is  no  denticu- 
lation,  and  the  name  fascia  is  certainly  misleading  ;  hence  the  senior  author  proposed 
(f>,  135)  to  employ /ascio/a  for  the  whole. 

i^  1228.  Fimbria,  fmh.—Fig.  121  ;  PI.  IV,  Fig.  14.  17.  Gray.  A,  627;  Quain,  A,  II, 
543,  544. 

Syn. — Corpus  fimbriatum,  taenia  hippocampi. 

The  strip  of  alba  forming  the  border  of  the  hypocampa  and  one  of  the  boundaries  of 
the  rima.     See  fornix  (§  1238). 

§  1229.  Fissura  ansata,  F.  an. — This  and  the  other  cerebral  fissures  (including  all 
the  fissures  named  in  §  1129  excepting  the  four  appertaining  to  the  myelon)  are  briefly 
discussed  in  the  last  part  of  this  chapter.     See  especially  the  Table  of  Synonyms  (§  1342). 

§  1230.  Fissura  dorsilateralis  (myelonis),  F.  dl.—F\g.  112;  PL  I,  Fig.  1.  Gray,  A, 
605  ;  Quain,  A,  II,  493. 

§  1231.  Fissura  dorsimesalis  {az.),  F.  dms.—F\g.  112 ;  PI.  I,  Fig.  1  ;  PI.  Ill,  Fig.  12. 
Gray,  A,  605  ;  Quain,  A,  II,  493. 

Syn. — The  "  posterior  fissure  of  the  cord." 

§  1232.  Fissura  ventrilateralis,  F.  vl.—F\g.  112,  116  ;  PI.  II,  Fig.  3.  Gray,  A,  605  ; 
Quain,  A,  II,  493. 

§  1233.  Fissura  ventrimesalis  {az.),  F.  vms.—Fig.  99,  100,  109, 112  ;  PI.  II,  Fig.  3. 
Gray,  A,  605  ;  Quain,  A,  II,  493. 

The  "  anterior  fissure  of  the  cord." 

§  1234.    Flocculus,  flc.—Grsij,  A,  634 ;  Quain,  A,  II,  518. 

We  are  not  sure  that  this  is  represented  in  the  cat,  although  it  has  been  homologized 
by  some  with  the  Lobulus  appendicularis. 

§  1235.  Foramen  caecum  {az.),  Fm.  ce.—Vl.  II,  Fig.  3,4.  Gray,  A,  610 ;  Quain,  A, 
II,  504. 

Syn. — Fossa  caeca — Spitzka.  3,  6. 


SYNONYMS    AND    REFERENCES.  479 

The  name  here  employed  was  used  by  Vlcq  d'Azyr  (A,  PI.  XVIII,  "  48"),  and  is  given 
in  Danglison ;  it  should,  we  think,  be  retained,  notwithstanding  the  somewhat  unusual 
use  o^ foramen. 

%  1236.    Foramen  conarii  {nz),  Fm.  m.— PI.  Ill,  Fig.  6. 

The  interval  between  the  postcommissura  and  the  Commissura  habenarum. 

g  1237.    Foramen  infundibuli  {az.),  Fni.  inf,—Fig.  118 ;  PI.  Ill,  Fig.  11. 

The  orifice  left  after  removal  of  the  hypophysis  and  infundibulum. 

§  1238.  Fornix  (az.),  /.-Fig.  117, 122  ;  PI.  II,  Fig.  4 ;  PI.  Ill,  Fig.  13  ;  PI.  IV,  Fig. 
14-20 ;  §§  1144,  1172,     Gray,  A,  627  ;  Quain,  A,  IT,  543. 

Syn. — Camara,  testudo  cerebri. 

A  subtriangular  fibrous  sheet,  forming  successively  the  cephalic  boundary  of  the  aula 
and  port®,  the  roof  of  the  aula,  and  part  of  the  floor  of  the  procoeliae.     (See  §  1457.) 

The  form,  constitution,  direction  and  relations  of  the  fornix  are  exceedingly  difficult  to 
describe,  and  indeed  are  not  fully  understood.  The  fornix  proper  includes  the  following 
parts  :  columncB,  commissura,  crista,  carina,  delta  and  Ipra.  The  fimbriae  are  its  caudo-lat- 
eral  prolongations  to  the  tips  of  the  hypocampal  lobules,  while  the  fibrous  fasciculi  consti- 
tuting the  columnse  are  described  as  beginning  in  the  thalami,  passing  ventrad  to  form  a 
figure-of-eight  turn  in  the  albicantia,  then  passing  dorsad  just  caudad  of  the  praecommissura 
to  form  the  lateral  halves  of  the  "  body  "  of  the  fornix,  which  again  are  continued  into  the 
fimbriae.  Between  the  thicker  lateral  parts  of  the  body  of  the  fornix  is  the  thin  and  ill- 
defined  portion  known  as  lyra.  * 

The  caudal  portion  of  the  fornix  is  in  contact  with  the  ventral  aspect  of  the  callosum 
at  and  for  a  short  distance  laterad  of  the  meson,  and  the  two  are  continuous  at  the  sple- 
nium.     See  callosum  (§  1195). 

The  feline  fornix  is  proportionally  much  wider  than  the  human,  and  may  be  torn  into 
several  bands  on  each  side,  as  indicated  by  the  v-shaped  lines  in  PI.  IV,  Fig.  14. 

§  1239.  Genu  {az.),  g.-F\g.  117 ;  PI.  II,  Fig.  4  ;  PI.  IV,  Fig.  17.  Gray,  A,  623  ;  Quain, 
A,  il,  538. 

Tiie  knee-like  cephalic  curvature  of  the  callosum,  ending  in  the  rostrum. 

%  1240.  Habena,  Ii.—Fig.  117,  122  ;  PI.  II,  Fig.  4 ;  PI.  IV,  Fig.  16;  §  1143.  Gray,  A, 
C30  ;  Quain,  A,  II,  549. 

Syn. — Habenula,  pedunculus  conarii. 

The  ridge  along  the  dorso-mesal  aspect  of  the  thalamus  ;  it  may  be  said  to  be  the  dor- 
sal limit  of  the  mesal  surface,  as  the  Sulcus  habenae  is  the  mesal  limit  of  the  dorsal  surface. 

The  habena  terminates  on  the  cephalic  slope  of  the  thalamus  as  a  more  or  less  distinct 
tubercle  which  marks  the  dorsal  limit  of  the  porta  ;  it  joins  its  platetrope  by  the  Cs.  habe- 
narum, forming  the  cephalic  boundary  of  the  Fm.  conarii. 

§  1241.    Hemiseptum  (cerebri),  hmspt.—¥ig.  117 ;  PI.  IV,  Fig.  16. 

This  is  the  lateral  half  of  the  septum  (lucidum),  which  see  (§  1315)  ;  its  mesal  surface, 
the  Area  septalis,  is  joined  with  its  platetrope  by  connective  tissue  (§  1137,  4). 

§  1242.  Hemisphaera,  hem.—Yxo-.  104,  110-118,  124,  125 ;  PI.  I,  Fig.  1,  2  ;  PI.  II,  Fig. 
3.  4  ;  PI.  Ill,  Fig.  5,  6,  11,  13  ;  PI.  IV,  Fig.  14-20. 

8yn. — Ganglion  hemisphseri cum,  hemicerebrum,  lobus  prosencephalicus. 

The  lateral  half  of  the  largest  portion  of  the  brain,  united  with  its  platetrope  by  the 
fornix,  callosum  and  praecommissura.  Its  cavity  is  the  procoelia,  and  the  striatum,  hypo- 
campa,  and  (in  man  and  monkeys)  calcar  are  thickenings  or  involutions  of  the  parietes. 
The  surface  is  convoluted,  presenting  fissurae  and  gyri.  The  cinerea  is  mostly  near  the 
surface,  forming  the  cortex  cerebri.     See  cerebrum,  §  120X. 


480  ANATOMICAL      TECHNOLOGY. 

§1243.  Hippocampus,  hm-p.—W\g.  133;  PI.  Ill,  Fig.  11;  PI.  IV,  Fig.  14,15,18; 
§  1147.     Gray,  A,  627  :  Quain,  A,  II,  541. 

Syn. — Hippocampus  major,  cornu  Ammonis. 

A  thickening  and  involution  of  the  parietes  of  the  medicornn,  forming  its  floor. 

The  convexity  constituting  the  hippocamp  corresponds  with  a  well-marked  ectal  fissure, 
the  hippocampal.     The  ectal  surface  also  presents  the  fasciola,  fimbria  and  F.  fimbrice. 

The  grounds  for  preferring  the  name  employed  by  Vicq  d'Azyr  (A,  61,  PI.  VII,  Fig. 
1,  3 ;  PI.  VIII,  Fig.  2),  and  ascribed  by  him  to  Arantius  and  Varolius,  are  briefly  stated  by 
the  senior  author  (0,  125  ;  14,  541).     See,  however,  p.  4006. 

§  1244.  Hypophysis  {az),  hph.—Fig.  Ill,  113,  110,  117;  PI.  II,  Fig.  3,  4  ;  §  1084. 
Gray,  A,  621  ;  Quain,  A,  II,  535 ;  Balfour,  A,  II,  358. 

Syn. — Corpus  pituitarium,  pituitary  gland. 

A  subcordate  mass  attached  to  the  Tuber  cinereura  by  a  tube,  the  infundibulum.  It 
does  not  appear  to  consist  of  true  nervous  tissue,  and  its  functions  are  wholly  unknown  ; 
but  it  is  constant  throughout  the  vertebrate  series,  excepting  Amphioxus  ;  see  Owen,  J. 

§  1245.   Incisura  hypocampae.  Inc.  hmp. — Fig.  118;  PI.  IV,  Fig.  11. 

A  more  or  less  distinct  crenation  of  the  mesal  border  of  the  hypocampal  lobuie,  where 
it  abuts  against  the  Tractus  opticus. 

§  1246.  Infundibulum  (as.),  inf.—¥\g.  116,  117 ;  PI.  II,  Fig.  3.  4.  Gray,  A,  621  ; 
Quain,  A.  II,  535. 

The  short  thin-walled  tube  by  which  the  hypophysis  is  connected  wuth  the  Tiiber 
cinereum. 

It  has  several  antiquated  synonyms,  but  the  name  here  given  is  almost  universally 
employed. 

§  1247.    Insula,  m*.— Gray,  A,  616  ;  Quain,  A,  II,  525. 

Syn. — Insula  Reilii,  Gyri  operti,  Lobulus  Fissurae  Sylvii,  Lobulus  Corporis  striati. 

In  man  and  monkeys,  and  perhaps  some  other  mammals,  the  cortex  cerebri  opposite 
the  striatum  is  elevated  and  more  or  less  convoluted.  By  the  outgrowth  of  the  neighbor- 
ing regions,  it  becomes  nearly  or  quite  concealed,  whence  the  name  Oyri  operti.  The 
insula  has  not  been  identified  in  the  cat ;  see  striatum,  §  1318. 

§  1248.  Interopticus,  inop. — The  interoptic  lobe  of  some  Reptiles  (Spitzka,  4, 5, 11) ; 
we  have  not  observed  it  in  the  cat. 

§  1249.  Iter  (az.),  it. — See  mesocoelia  (§  1263).  The  entire  name  is  iter  a  tertio  ad 
quartum.  ventriculum,  but  as  the  only  other  iter  {iter  ad  infundibulum)  is  rarely  used,  the 
senior  author  has  suggested  {9,  135)  the  single  word  as  a  convenient  designation  of  the 
contracted  mesocoelia  of  mammals. 

§  1250.   Limes  alba,  Im.  celb.—Fig.  116  ;  PI.  I,  Fig.  2  ;  PI.  II,  Fig.  3. 

The  Radix  lateralis  of  the  olfactory  lobe  presents  two  distinct  tracts  or  paths  for 
which,  from  their  color,  the  senior  author  has  proposed  (5>,  135  ;  14,  537)  the  names  limes 
alba  and  limes  cinerea.     The  latter  is  laterad  of  the  fornix. 

§  1251.   Limes  cinerea,  Im.  cm.— See  limes  alba  (§  1250). 

§  1252.  Liquor  coeliarum,  Iq.  c. — The  liquor  ventriculorum  cerebri.  The  coelian  sur- 
faces are  always  moistened  by  a  serous  liquid,  secreted  presumably  by  the  plexuses.  We 
have  never  observed  an  abnormal  increase  of  this  liquid  in  cats,  but  hydrocephalus  has 
been  recorded  of  several  domesticated  animals  as  well  as  of  man. 

§  1253.  Lobulus  appendicularis  (cerebelli).  LI.  ap.—Fig.  116:  PI.  I.  Fig.  2  ;  PI.  II, 
Fig.  3. 

The  name  has  been  applied  to  the  more  or  less  distinct  projection  consisting  of  two  or 


SYNONYMS    AND    REFERENCES.  481 

three  folia  or  laminae  of  tlie  lateral  lobe  of  the  cerebellum.  It  rests  in  the  Fossa  appen- 
dlcularig  of  the  periotic  bone  (Fig,  59,  Fs.  ap.).  It  is  larger  in  dogs  (see  Wilder,  11,  21?, 
Fig.  1),  and  very  large  and  long  in  the  bear  and  seal.  The  name  flocculus  has  sometimes 
been  applied  to  it,  but  its  homology  with  that  part  of  the  human  cerebellum  is  not  clear, 

§  1254  Lobulus  hypocampae,  LI  hmp.—Fig.  116;  PI.  I,  Fig.  1 ;  PI.  II,  Fig.  3;  PI. 
UI.'Fig.  6;  PL  IV,  Fig.  14,  17. 

JSyn. — Alveus  (?),  subiculum  Cl),  protuberantia  natiformis. 

The  senior  author  had  suggested  (,9,  135)  for  this  the  single  name  monticulus,  bat 
withdrew  it  {14,  537)  on  the  representation  of  Spitzka  (7,  165)  that  the  name  had  been 
applied  to  a  part  of  the  cerebellum. 

§  1255.  Lobus  lateralis  (cerebelli),  L.  l.—Fig.  116  ;  PI.  I,  Fig.  1,  2  ;  PI.  II,  Fig.  3  ; 
PI.  IV,  Fig.  15.     Gray,  A,  634 ;  Quain,  A,  II,  517. 

Syn. — The  lateral  lobe  of  the  cerebellum.  This  and  the  mesal  lobe  or  vermis  are  not 
well  defined  from  each  other.  The  Lobulus  appendlcularis  is  an  appendage  of  the  L. 
lateralis. 

§  1256.  Lobus  olfactorius,  L.  ol—¥ig.  116,  117  ;  PI.  I,  Fig.  1,  2 ;  PI.  II,  Fig.  3,  4 ; 
PI.  IV,  Fig.  15-19.     Gray,  A,  636  ;  Quain,  A,  II,  506. 

8yn. — Bulbus  olfactorius,  olfactory  lobe,  olfactory  nerve. 

The  enlarged  extremity  of  each  half  of  the  rhinencephalon  which  gives  off  the  olfac- 
tory nerves.  In  man,  it  and  the  crus  are  so  small  as  to  have  been  called  olfactory  nerve. 
It  contains,  however,  a  distinct  rhinocoelia ;  see  pero  and  pes. 

%  1257.  Lobus  temporalis,  L.  tmp.—Fl  I,  Fig.  2  ;  PI.  II,  Fig.  3 ;  PI.  Ill,  Fig.  5  ;  PI. 
IV,  Fig.  14     Gray,  A,  616  ;  Quain,  A,  II,  5^30. 

That  portion  of  the  hemisphere  which  is  caudad  of  the  Sylvian  fissure.  Its  dorsal 
limit  is  not  defined.  Its  ventral  end  is  the  Lobulus  hypocampm,  and  the  surface  ventro- 
mesad  of  the  F.  postrhinalis  is  the  Tractus  postrhinalis. 

§  1258.    Lyra  {az\  ly.—F\g.  122  ;  PI.  IV,  Fig.  14     Gray,  A,  628  ;  Quain,  A,  II,  544 

Syn. — Psalterium,  corpus  psalloides,  lamina  medullaris  triangularis  cerebri,  spatium 
trigonum. 

This  name  is  applied  to  part  of  the  ventral  surface  of  the  fornix.     It  is  not  well  defined. 

§  1259.  Medicommissura  {az.),  mcs.—Fig.  117,  122  ;  PI.  II,  Fig.  4;  PI.  Ill,  Fig.  6,  IS; 
PI.  IV.  Fig.  16 ;  §  1143.     Gray,  A,  630  ;  Quain,  A,  II,  546. 

8ya. — Commissura  media,  commissura  mollis,  the  middle  or  soft  commissure. 

The  junction  of  the  two  tbalami  in  the  dorsal  part  of  the  diacoelia.  It  seems  to  consist 
of  cells  rather  than  fibers. 

§  1260.  Medicornu,  mew.— Fig.  113,  118,  119,  121  ;  PI.  Ill,  Fig.  11  ;  PI.  IV,  Fig. 
14.  15  ;  §  1147.     Gray,  A,  626 ;  Quain,  A,  II,  541. 

Syti  — ^Cornu  medium,  cornu  descendens,  cornu  inferius,  digital  cavity. 

The  strongly  curved  extension  of  the  cella  media  of  the  procoelia  to  the  tip  of  the  L. 
temporalis ;  its  floor  is  formed  by  the  hypocampa, 

§  1261.   Medipedunculus  (cerebelli),  wpd.—%  1141.     Gray,  A,  655  ;  Quain,  A,  II,  516. 

Syn. — Pedunculus  medius,  crus  medium,  processus  e  cerebello  ad  pontem,  brachium 
pontis. 

The  subcylindrical  fibrous  mass  connecting  the  pons  with  the  cerebellum.  It  is  over- 
hung and  concealed  by  the  L.  lateralis.  It  was  called  pontibrachium  by  the  senior  auth^i 
(f>,  136)  under  a  misapprehension. 

§  1262.  Mesencephalon  (az.),  msen.—F\g.  110-114,  116-118 ;  §  1061.  Gray,  A,  111 ', 
Quain,  A,  II,  755. 

Syn. — Midbrain.     It  embraces  the  optici,  postoptici  and  crura. 
31 


482  A  NA  TOMICAL    TECHNOLO  G  Y, 

§  1263.  Mesoccelia  (az.),  msc— Fig.  110-113,  117;  PI.  II,  Fi^.  4;  §  1055.  Gray,  A, 
680  ;  Quain,  A,  II,  552. 

Syn. — Aquseductns  Sylvii,  iter  a  tertio  ad  quartum  ventriculum,  ventriculus  opticus, 
Tentriculus  mesencepliali. 

The  mesenceplialic  cavity,  enclosed  by  tlie  crura  cerebri,  the  optici  and  postoptici,  and 
opening  cephalad  into  the  diaccelia  and  caudad  into  the  epicoelia. 

§  1264.  Metacoelia  (as.),  m^c— Fig.  113,  117  ;  PI.  II,  Fig.  4 ;  §  1065.  Gray,  A,  635 ; 
<iuain,  A,  II,  512. 

Byn. — Ventriculus  quartus,  caudal  portion.  As  has  been  admitted  (§  1225),  it  is  diffi- 
cult, perhaps  impossible,  to  define  accurately  the  limits  of  the  metaccelia  and  epiccelia. 

§  1265.  Metaplexus,  mtpx.—Y\^.  116  ;  PI.  II,  Fig.  3.  Luschka,  A,  PI.  Ill ;  Gray,  A, 
636  ;  Quain,  A,  II,  518. 

Syn. — Plexus  choroideus  ventriculi  quarti,  plexus  choroideus  inferior. 

We  have  not  yet  satisfied  ourselves  respecting  the  nature  and  connections  of  this 
plexus,  and  have  provisionally  designated  the  prominent  plexus  between  the  dorsal  border 
of  the  medulla  and  the  cerebellum  as  the  metaplexus  lateralis. 

%  1266.  Metencephalon  {az\  mten.—Fig.  110-113, 116;  PI.  I,  Fig.  1,  2;  PI.  II,  Fig. 
3,  4 ;  PI.  Ill,  Fig.  12.     Gray,  A.  Ill ;  Quain,  A,  II,  755. 

Syn. — Medulla,  as  far  as  the  pons.     See  §§  1061,  1225. 

§  1267.  Metatela  {az.),  mttl.—Fig.  Ill,  112,  116;  PI.  II,  Fig.  4;  PI.  Ill,  Fig.  12. 
Luschka,  A,  PI.  III. 

Syn. — Tela  choroidea  inferior. 

Notwithstanding  this  atrophied  roof  of  the  metacoelia  is  so  obvious  with  Amphibia  as 
ro  have  been  once  mistaken  for  the  cerebellum,  it  is  usually  ignored  in  the  dissection  of 
the  mammalian  brain,  probably  because  of  its  tenuity  and  its  liability  to  be  torn  off  with 
the  cerebellum. 

As  has  been  stated  in  several  places,  there  is  much  to  be  learned  respecting  the  struc- 
ture of  the  metatela,  the  arrangement  of  the  metaplexus  and  the  "  Foramen  of  Magendie." 
The  probability  of  the  existence  of  the  latter  is  increased  by  the  experiments  of  West- 
brook  (1),  which  should  be  repeated  upon  the  cat ;  detailed  descriptions  and  enlarged 
tigures  are  required  (§  1082). 

§  1268.  Myelon  (az.),  my.—F\g.  88,  104,  109-113,  116;  PI.  I,  Fig.  1,2;  PI.  II,  Fig. 
3,  4.     Gray,  A,  604 ;  Quain,  A,  II,  489. 

Syn. — Medulla  spinalis,  spinal  cord,  spinal  marrow,  chorda  spinalis. 

It  is  described  in  §  1006  and  in  connection  with  the  figures  above  named. 

§  1269.  Nervus  abducens,  N.  nb. — This  and  the  other  cranial  nerves  (i-xii)  are 
treated  of  in  the  next  chapter.  The  ectal  origins  are  shown  in  Fig.  116  and  in  PI.  II, 
Fig.  3. 

§  1270.  Obex,  oh. — We  have  not  yet  identified  this  in  the  cat.  It  is  mentioned  by 
Spitzka  {3,  18),  and  also,  we  think,  by  Meynert  (Strieker,  A). 

§  1271.  Oliva,  o^i;.— According  to  the  Am.  Jour,  of  Neurology,  etc.  (I,  102),  the  eleva- 
tion called  Area  elliptica  (Fig.  116 ;  PI.  II,  Fig.  3,  Ar.  el.)  represents  the  oliva  or  Corpus 
olivarium,  notwithstanding  the  funiculi  of  the  iV.  hj/poglossus  emerge  laterad  of  it. 

§  1272.  Opticus  (Lobus),  op.— Fig.  110-112,  114,  116,  117;  PI.  11,  Fig.  4;  PI.  Ill, 
if^g.  7,  8,  9, 12 ;  PI.  IV,  Fig.  18,  19 ;  §  1142.     Gray,  A,  681 ;  Quain,  A,  II,  551. 

Syn. — Corpus  bigeminum  anterius,  natis  cerebri,  one  of  the  corpora  quadrigemina, 
cfl^lialic  lobe  of  the  mesencephalon. 

As  seen  in  PI.  Ill,  Fig.  7,  8,  9,  the  opticus  is  more  regularly  convex  and  less  deviated 
than  the  postopticus. 


SYNONYMS    AND    REFERENCES.  483 


B  §  1273.  Pero  (olfactorius),  po.—V\.  IV,  Fig.  16;  §  1139.  Meynert  (Strieker,  A,  Fig. 
261). 

This  name  was  proposed  by  the  senior  author  (.9,  135)  for  the  softer  ectal  layer  of  the 
Lohus  olfactorius  from  which  the  olfactory  nerves  arise.  The  word  signifies  a  kind  of 
boot  made  of  raw  hide,  and  seems  more  appropriate  than  the  term  Bulbus  olfactorius 
used  by  Meynert  (Strieker,  A,  671). 

§  1274.  Pes  (olfactorius),  ps.  ul.—V\.  IV,  Fig.  16;  g  1139.  Meynert  (Strieker,  A, 
Fig.  261). 

This  name  was  proposed  by  the  senior  author  (.9,  126  ;  14,  538)  for  the  ental  and 
fibrous  poraon  of  the  Lobus  olfactorius.  It  is  in  harmony  with  the  term  crus,  already  in 
use,  and  with  pero,  which  was  proposed  at  the  same  time,  and  less  apt  to  be  misunderstood 
than  the  term  Lobus  ol.  used  in  this  restricted  sense  by  Meynert  (Strieker,  A,  671). 

§  1375.  Pia  (mater),  pi.— Fig.  Ill,  113,  131-123;  §  1078.  Gray,  A,  609  ;  Quain,  A, 
II,  571.        • 

8yn. — Meninx  vasculosa,  membrana  vasculosa,  membrana  tenuis. 

The  immediate  envelope  of  the  myelencephalon,  dipping  into  the  fissures  and  sup- 
porting the  vessels.     Its  relations  to  the  telae  and  plexuses  are  not  fully  understood, 

§  1276.  Pons  (Varolii),  (az.),  ^n.—Fig.  116,  118;  PL  II,  Fig.  3,4;  PI.  Ill,  Fig.  9,  U. 
Gray,  A,  610 ;  Quain,  A,  II,  511,  756. 

Syn—Von^  cerebelli,  tuber  annulare,  protuberantia  basilaris. 

The  bridge  like  mass  upon  the  basis  encephali  connecting  the  two  sides  of  the  cerebel- 
lum. It  forms  a  prominent  landmark  of  the  mammalian  brain,  and  is  not  present  with 
the  lower  vertebrates. 

§  1377.  Porta,  p.— Fig.  110-113,  130,  123;  PI.  Ill,  Fig.  13;  PL  IV,  Fig.  14,16,  18, 19; 
§  1065.     Gray,  A,  630  ;  Quain,  A,  II,  544. 

Syn. — Foramen  Monroi,  lateral  orifice  of  the  y-shaped  Foramen  Monroi. 

This  more  or  less  constricted  communication  between  the  aula  and  the  procoelia  is 
described  in  connection  with  the  figures  above  named  and  in  §§  1096,  1145,  1151.  The 
reasons  for  adopting  the  single  word  in  place  of  the  compound  term  have  been  given  by 
the  senior  author  {3). 

%  1278.  Portio  depressa  (praeperforati),  Pt.  d. — The  caudal  and  depressed  portion  of 
the  (Locus)  praeperforatus,  which  see  (§  1393). 

§  1379.  Portio  diencephalica  (Cruris  cerebri),  Pt.  den.— Fig.  116,  118  ;  PI.  Ill,  Fig.  9, 
11 ;  §  1142. 

In  the  cat  the  Crus  cerebri  is  traversed  by  the  cimbia,  and  its  ventral  surface  is  sepa- 
rated thereby  into  a  caudal  or  mesencephalic  portion  and  a  cephalic  or  diencephalic.  The 
latter  presents  a  longitudinal  ridge,  mesad  of  which  is  the  quadrans,  while  the  postgenicu- 
latum  lies  just  laterad  of  it. 

§1380.  Portio  mesencephalica  (Cruris  cerebri),  Pt.  msen.—F'ig.  116,  118;  PI.  II, 
Fig.  3 ;  PI.  III.  Fig.  11  ;  §  1143. 

This  is  the  part  of  the  crus  which  is  visible  upon  the  undissected  brain  between  the 
pons  and  the  hemisphere.  See  Crus  cerebri  (§  1315),  cimbia  (§  1303),  and  Portio  dience- 
pJialica  {%  1379). 

§  1381.  Portio  prominens  (praeperforati),  Pt.  p. — The  cephalic,  elevated  and  usually 
furrowed  portion  of  the  (Locus)  praeperforatus,  which  see  (§  1393). 

§  1383.   Portiplexus,  PJ92;.— Fig.  113,  133. 

This  name  was  proposed  by  the  senior  author  {9,  136)  for  that  small  portion  of  the 
plexus  which  hangs  in  the  porta. 


484  ANATOMICAL    TECHNOLOGY, 

§  1283.  Postcommissura  {az.),  pcs.—F'ig.  Ill,  112,  117;  PL  II,  Fig.  4;  PL  III; 
§  1143.     Gray,  A,  630 ;  Quain,  A,  II,  546. 

Syii. — Commissura  posterior. 

Composed  of  transverse  fibers  formiug  the  caudal  part  of  tlie  roof  of  the  diacoelia,  and 
thus  joining  the  dorsal  portions  of  the  thalami. 

§  1284.    Postcornu,  pc?/.— Gray,  A,  635  ;  Quain,  A,  II,  542. 

Syn. — Cornu  posterius  ventriculi  lateralis,  cavitas  digitata. 

This  caudal  prolongation  of  the  proccelia  is  normally  present  only  in  man,  monkeys, 
seals  and  cetacea.  The  hydrocephalous  brain  of  a  dog  reported  by  the  senior  author  {23) 
presented  a  distinct  postcornu,  so  that  perhaps  it  may  be  regarded  as  normally  rudimentary 
or  undeveloped  rather  than  totally  absent  in  the  ordinary  mammals. 

§  1285.  Postgeniculatum,  ^^r^i.— Fig.  118  ;  PL  III,  Fig.  7-11 ;  §  1144.  Gray,  A,  631 ; 
Quain,  A,  II,  552. 

Syn. — Corpus  geniculatum  internum. 

The  elevation  at  the  side  of  the  diencephalon,  between  the  Tractus  opticus  and  the 
cimbia.     It  is  propoitionally  much  larger  in  the  cat  than  in  man. 

§  1286.  Postopticus,  pnp.—Yxg.  114  ;  PL  II,  Fig.  2;  PL  III,  Fig.  7-9  ;  PL  IV,  Fig. 
18,  19  ;  §  1142.     Gray,  A,  631  ;  Quain,  A,  II,  551. 

Syn. — Testis  cerebri,  corpus  bigeminum  posterius,  one  of  the  corpora  quadrigemina, 
caudal  lobe  of  the  mesencephalon. 

The  marked  elevation  just  cepha^ad  of  the  cerebellum  and  valvula. 

§  1287.    Postpedunculus,  ppd.—%  1141  ;  Gray,  A,  635  ;  Quain,  A,  II,  516. 
Syn. — Processus  e  cerebello  ad  medullam  oblongatam  ;  restibrachium  (Spitzka,  7, 165). 
The  fibrous  fasciculus  passing  from  the  dorsal  aspect  of  the  metencephalon  dorso- 
cephalad  to  the  cerebellum,  mesad  of  the  medipedunculus. 

§  1288.  Praegeniculatum  (Corpus),  prgn.—Fl.  Ill,  Fig.  7-9;  §  1144.  Gray,  A,  631  ; 
Quain,  A,  II,  552. 

Syn. — Corpus  geniculatum  externum. 

There  seem  to  be  no  distinct  lines  of  demarcation  between  the  Tractus  opticus,  the 
praegeniculatum  and  the  thalamus. 

§  1289.  Postperforatus  (Locus),  {az.),ppf.—¥ig.  116,  118  ;  PL  II,  Fig.  3  ;  PL  III,  Fig. 
11.     Gray,  A,  621  ;  Quain,  A,  II,  535. 

Syn. — Locus  perforatus  posticus,  pons  Tarini. 

A  small  triangular  area  overhung  by  the  albicantia,  and  presenting  a  few  pores  for  the 
transmission  of  vessels.     It  is  apparently  smaller  than  in  man. 

§  1290.  Praecommissura  (az.),  prcs.—Fig.  Ill,  112, 117 ;  PL  II,  Fig.  4 ;  PL  IV,  Fig. 
14,  16,  17  ;  §§  1067,  1152.     Gray.  A,  630  ;  Quain,  A,  II,  546. 

Syn. — Commissura  anterior  cerebri. 

At  the  meson  this  commissure  is  a  subcylindrical  fibrous  fasciculus  just  cephalad  of 
the  Columnas  fornicis.  It  expands  laterad  and  reaches  the  striata  and  Crura  olfactoria, 
which  it  thus  connects  across  the  meson.  In  man,  according  to  Meynert  (Strieker,  A,  680), 
the  connection  of  the  olfactory  lobes  with  the  commissure  is  slight. 

§  1291.  Praecornu,  prcu.—Fig.  113,  120;  PL  IV,  Fig.  15,  16, 18,  19  ;  §  1149.  Gr^y, 
A,  625;  Quain,  A,  11,541. 

Syn. — Cornu  anterius  ventriculi  lateralis. 

The  cephalic  portion  of  the  procoelia.  It  is  quite  high,  but  compressed,  the  striatum 
projecting  into  it.  The  ventro-cephalic  end  narrows  suddenly  to  become  continuous  with 
the  rhinoccelia. 


SrXOXYJfS    AND    REFERENCES.  485 

§  1292.    Praepedunculus,  ;)rp(?.— §  tl41.     Gray,  A,  635:  Quain,  A,  II,  576. 

Syn. — Pedunculus  cerebelli  superior,  processus  e  cerebello  ad  testim,  crus  cerebelli 
superius,  testibracliium. 

The  praepedunculi  extend  from  the  cerebellum  to  the  base  of  the  postoptici,  and  form 
the  walls  of  the  cephalic  and  longer  part  oi'  the  epicoelia. 

§  1293.  Praeperforatus  (Locus),  ^rp/.— Fig.  116,  118  ;  PI.  II,  Fig.  3  ;  PI.  Ill,  Fig.  11. 
Gray,  A,  621  ;  Quain,  A,  II,  536. 

Syn. — Locus  perforatus  anterior  s.  anticus,  anterior  perforated  space. 

The  irregular  area  just  cephalad  of  the  chiasma.  In  man  it  is  comparatively  small,  but 
in  the  cat  it  is  larger  and  presents  two  quite  distinct  portions,  a  cephalic  which  is  more 
or  less  elevated  and  often  distinctly  marked  by  longitudinal  furrows  and  ridges,  and  a  cau- 
dal which  is  smaller,  depressed,  and  smooth  excepting  for  the  vascular  perforations  which 
characterize  the  entire  area.  The  two  divisions  are  hence  named  Portio  prominens  and 
Portlo  depressa.  Between  the  depressed  portions  is  the  slight  gray  elevation  of  the  terma, 
forming  part  of  the  floor  of  the  Recessus  opticus. 

§  1294.  Procoelia,  prc.—¥\g.  110-113  ;  PI.  IV,  Fig.  15,  16,  18, 19;  §  1064.  Gray,  A, 
624  ;  Quain,  A,  II,  539. 

Syn. — Ventriculus  lateralis,  ventriculus  tricornis,  lativentriculus,  first  or  second  ven- 
tricle. 

The  lateral  cavity  of  the  prosencephalon,  communicating  through  the  porta  with  the 
aula  and  thus  with  its  platetrope,  and  with  the  mesal  series  of  coeliae.  Cephalad  it  opens 
into  the  rhinoccelia. 

§  1295.  Proplexus,  prpx.—F\g.  113,  121  ;  PI.  IV,  Fig.  15,  18  ;  §§  1066,  1149.  Gray, 
A,  627  ;  Quain,  A,  II,  545. 

Syn. — Plexus  choroideus  ventriculi  lateralis. 

The  larger  part  of  this  plexus  of  the  procoelia  is  formed  by  the  intrusion  of  the  velum 
or  of  vessels  thereof  between  the  fimbria  and  the  Sulcus  limitans  so  as  to  appear,  still  cov- 
ered by  endyma,  in  the  medicornu.     Its  length  thus  coincides  with  that  of  the  rima. 

A  smaller  portion  of  the  proplexus  projects  laterad  into  the  praecornu,  as  shown  in  PI. 
IV,  Fig.  18. 

Respecting  the  continuity  of  the  endyma  upon  the  proplexus,  see  Todd  (A,  III,  704) ; 
Balfour  (A,  II,  364,  Fig  260,  261) ;  Mivart  (B,  267) ;  Gray  (A,  627) ;  Quain  (A,  II,  546). 

§  1296.  Prosencephalon  {az.),  pren.—F\g.  110-118  ;  PI,  I,  Fig.  1,  2  ;  PI.  II,  Fig.  3,  4  ; 
PI.  Ill,  Fig.  5,  6,  11,  13  ;  PI.  IV,  Fig.  14^20  ;  §§  1061,  1138,  1145.  Gray,  A,  111  ;  Quain, 
A,  II,  759. 

Syn. — Cerebrum,  hemisphserae,  forebrain. 

The  cavities  of  the  prossncephalon  are  the  aula,  the  portm  and  the  procidicB. 

§  1297.  PseudoccElia  {az.\  p8c.—%^  1064,  1137  (4),  1162  (2).  Gray,  A,  627 ;  Quain,  A, 
II,  543. 

Syn. — Ventriculus  quintus,  ventriculus  septi  pellucidi,  ventriculus  Sylvii,  incisura 
septi,  sinus  septi  pellucidi,  fifth  ventricle. 

In  man  the  mesal  surfaces  of  the  hemispheres  between  the  callosum  and  fornix  are 
separated  by  an  interval,  the  "  fifth  ventricle."  In  the  cat  the  two  hemisepta  are  in  con- 
tact, and  the  pseudocoeiia  does  not  exist. 

P  1298.  Pyramis,  py.—F\g.  116  ;  PI.  II,  Fig.  3,  4  ;  §  1140.  Gray,  A,  612  ;  Quain,  A, 
n,  504. 

Syn. — Corpus  pyramidale,  prepyramid,  ventripyramid,  anterior  pyramid. 

At  the  side  of  the  meson,  iust  caudad  of  the  pons  and  extending  a  little  caudad  of  the 


486  AIYATOMICAL    TECHNOLOGY. 

Area  ovalis.  The  pyramids  are  commonly  regarded  as  continuations  of  the  lateral  rather 
than  of  the  ventral  columns  of  the  myelon. 

The  use  of  the  short  term  pyrainis  was  suggested  by  Spitzka  (7,  165). 

The  "  decussation  of  the  pyramids  "  does  not  appear  at  the  surface,  but  maybe  demon- 
strated by  divaricating  their  caudal  portions. 

§  1299.   Quadrans,  g.— Fig.  118  ;  PI.  Ill,  Fig.  9,  11  ;  §  1144. 

This  nauie  was  proposed  by  the  senior  author  (.9,  136  ;  14,  544)  for  an  area  of  the  ven- 
tral aspect  of  the  Crus  cerebri  which  is  approximately  the  fourth  of  a  circle.  It  is  not 
always  distinctly  marked. 

§  1300.  Radix  intermedia  (Cruris  olfactorii),  Bx.  m.— Gray,  A,  638 ;  Quain,  A, 
II,  537. 

Syn. — Radii  media,  the  middle  root  of  the  olfactory  tract.  As  stated  in  §  1161,  it  is 
not  apparently  differentiated  in  the  cat. 

This  and  the  two  following  technical  terms  for  the  olfactory  "  roots  "  were  proposed  by 
the  senior  author  (.9,  136  ;  14,  538)  as  less  apt  to  be  misunderstood  than  the  current  ver- 
nacular words. 

§  1301.  Radix  lateralis  (Cruris  olfactorii),  Bx.  /.—Fig.  116  ;  PI.  II,  Fig.  3  ;  §  1161. 
Gray,  A,  638  :  Quain,  A,  II,  536. 

/%7i.— Radix  externa,  external  root  of  the  olfactory  tract. 

See  Limes  alba,  §  1250. 

§  1302.  Radix  mesalis  (Cruris  olfactorii),  Bx.  ms.— Fig.  116  ;  PI.  II,  Fig.  3,  4  ;  §  1161. 
Gray,  A,  637  ;  Quain,  A,  II,  537. 

i&^».— Radix  interna,  inner  or  internal  root  of  the  olfactory  tract. 

In  man  this  root  is  wholly  ventral  in  position,  but  in  the  cat  it  passes  obliquely  mesad 
and  is  continuous  with  the  region  between  the  postradical  and  prseradical  fissures. 

§  1303.  Radix  motoria  (Nervi  trigemini),  Bx.  mt. — The  smaller  motor  root  of  the  N. 
trigeminus  ;  see  Chap.  XI  and  PI.  II,  Fig.  3. 

§  1304.  Radix  sensoria  (Nervi  trigemini),  Bx.  sn. — The  larger  and  sensory  root  of 
the  N.  trigeminus  ;  see  Chap.  XI  and  PI.  II,  Fig.  3. 

§  1305.    Recessus  aulse  (az.),  B.  a.— Fig.  117;  PI.  II,  Fig.  4;  PI.  IV,  Fig.  14;  §  1172. 

The  slight  space  between  the  Columnae  fornicis  just  ventrad  of  the  Crista  and  dorsad 
of  the  prsecommissura.  Its  cephalic  wall  is  exceedingly  thin  and  has  not  received  a  special 
name,  but  is  evidently  a  part  of  the  original  terma. 

§  1306.  Recessus  opticus  B.  op.— Fig.  117,  118 ;  PI.  II,  Fig.  4  ;  PI.  III.  Fig.  11. 

As  best  seen  in  PI.  Ill,  Fig.  11,  there  is  a  distinct  recess  just  dorsad  of  thechiasmaon 
each  side.  It  seems  to  correspond  with  what  Mihalkovics  (A,  79)  calls  by  the  name  above 
given.     Together  they  constitute  the  ventro-cephalic  part  of  the  aula. 

§  1307.  Recessus  praepontilis  (az.),  B.  prpn.—Fig.  116,  117,  118;  PI.  II,  Fig.  3,  4  ; 
PL  III,  Fig.  11. 

This  name  was  proposed  by  the  senior  author  (.9,  136;  14,  538)  for  the  mesal  pit 
formed  by  the  overhanging  of  the  cephalic  border  of  the  pons  ;  it  is  sometimes  quite  deep. 

§  1308.  Regio  aulica  (az.),  Bg.  a. — This  name  was  proposed  by  the  senior  author 
(9,  136  ;  14,  538)  for  the  complex  region  about  the  aula.  Within  a  radius  of  1  cm.  from 
the  Crista  fornicis  occur  a  large  number  of  parts  the  structure  and  relations  of  which  are 
inadequately  known  and  far  from  easy  to  elucidate. 

§  1309.   Restiforme  (Corpus),  rs^.— Gray,  A,  611  ;  Quain,  A,  II,  505. 

Syn. — Crus  e  cerebello  ad  meduUam. 

This  part  of  the  metencephalon  is  not  distinctly  shown  upon  any  of  the  figures,  and  we 


SYNONYMS    AND    REFERENCES.  487 

have  not  accurately  compared  it  with  the  corresponding  part  in  man.  As  indicated  by 
the  synonym,  the  restifoj^me  is  sometimes  regarded  as  identical  with  the  -posipedunculuSy 
but  even  if  they  contain  the  same  fibers,  the  latter  should  probably  be  defined  as  the  con- 
tinuation of  the  former  to  the  cerebellum  (Qaain,  A,  II,  505). 

Between  the  restiforme  and  the  Area  ovalis  is  a  smooth  rounded  elevation  which  we 
have  not  been  able  to  identify.  Nearly  opposite  the  cephalic  end  of  the  Area  elliptica  it 
ceases,  apparently  covered  in  by  the  union  of  the  parts  at  its  sides. 

§  1310.  Rhinencephalon  (a2. ),  r^eti.— Fig.  110-112,  116,  117;  PI.  I,  Fig.  1,2;  PI.  II, 
Fig.  3.  4;  PI.  IV,  Fig.  15-19  ;  §  1061.     Quain,  A,  11,  755. 

This  name  seems  to  have  been  employed  first  by  Owen  (A,  I,  283)  as  a  convenient  des- 
ignation of  the  olfactory  lobes  and  their  crura.  The  observations  of  Milnes  Marshall  (.5), 
as  presented  by  Balfour  (A,  II,  382),  require  considerable  modification  of  the  views  here 
adopted  respecting  the  constitution  of  the  encephalic  segments.  The  term  rhinenccphala 
is  used  by  Balfour  (A,  II,  366) ;  §  1150. 

§  1311.  Rhinocoelia,  rA^.— Fi^.  110-112;  PI.  IV,  Fig.  16;  §  1150.  Gray,  A,  115; 
Meynert  (Strieker,  A,  Fig.  261). 

Syn. — Ventriculus  lobi  olfactorii,  ventriculus  rhinencephalicus,  ventriculus  olfactorius. 

The  cavity  of  the  Lobus  olfactorius,  communicating  with  the  ventro-cephalic  part  of 
the  praecornu.  Though  slender  in  the  cat,  it  is  perfectly  distinct,  but  is  either  obliterated 
in  the  adult  human  subject  or  so  small  as  to  have  escaped  notice.  The  human  olfactory 
lobes  are  rarely  obtained  in  a  fit  condition  for  accurate  observation. 

§  1312.  Rima,  r.— Fig.  118,  121 ;  PI.  Ill,  Fig.  11  ;  PI.  IV,  Fig.  14  ;  §§  1083,  1144, 1155. 
Gray,  A,  627  ;  Quain,  A,  II,  544. 

Syn. — Rima  transversa  cerebri  magna,  fissura  transversa  magna,  fissura  Bichatii. 

The  line  of  atrophy  or  abrogatipn  of  the  proper  nervous  parietes  of  the  procoelia  from 
the  dorsal  end  of  the  porta  to  near  the  tip  of  the  medicornu.  Along  this  line  there  enters 
either  the  margin  of  the  velum,  which  is  a  fold  of  pia,  or  vessels  therefrom,  to  constitute 
the  proplexus.  Since,  however,  the  endyma  is  continued  from  the  margins  of  the  rima 
upon  the  intruded  pia  or  vessels,  these  latter  can  be  said  to  enter  the  procoelia  only  in  the 
sense  in  which  an  abdominal  viscus  enters  the  peritoneal  cavity. 

Of  the  two  margins  of  the  rima,  one  is  certainly  formed  by  the  fimbria,  which  is  con- 
tinuous, through  the  hypocampa,  with  the  caudal  and  thus  with  the  dorsal  part  of  the 
hemisphere.  Concerning  the  other  margin  we  are  in  doubt.  In  man  it  is  probably  the 
Tcmia  (semicircularisj,  but  this  part  has  not  yet  been  identified  in  the  cat,  and  we  have 
not  personally  examined  the  Cauda  striati.  We  content  ourselves,  therefore,  with  the 
general  statement  that  the  fimbria  lies  in  the  Sulcus  limitans  and  that  the  proccelian 
endyma  is  reflected  upon  the  proplexus  from  the  fimbria  and  from  the  striatum  or  such 
other  parts  as  may  form  the  cephalic  slope  of  the  Sulcus.  At  about  5  mm.  from  the  tip 
of  the  cornu  the  rima  ceases,  and  the  cornu  is  completely  encompassed  by  nervous  sub- 
stance. 

The  Name. — The  terms  above  enumerated  are  not,  strictly  speaking,  synonyms.  They 
were  all  applied  under  a  misapprehension  still  commonly  entertained  that  there  is  a  lack 
of  all  the  ccelian  parietes  along  a  line  extending  between  the  tips  of  the  medicornua,  so 
that  the  medicornua  and  diaccelia  were  in  direct  communication  both  vdth  each  other  and 
with  the  ectal  surface  of  the  brain.  With  human  brains  in  the  condition  in  which  they 
frequently  are  obtained,  removed  without  sufficient  care  and  roughly  handled,  such  a  solu- 
tion of  continuity  may  easily  be  demonstrated  ;  but  it  is  certainly  artificial,  and  the  names 
applied  to  it  need  not  be  retained  in  the  same  sense.  To  avoid,  however,  th«  introduction 
of  a  new  term,  the  senior  author  proposed  {9, 136  ;  14,  541)  the  single  short  word  rima 


488  ANATOMICAL     TECHNOLOGY. 

to  signify  so  much  of  the  "  rima  transversa  cerebri  magna"  as  has  been  indicated  above. 
When  used  for  the  interval  between  the  chordce  vocalefi,  the  compound  term  rima  glottidis 
is  commonly  employed. 

§  1313.   Ripa,  rp.—V\.  Ill,  Fig.  7  ;  PI.  IV,  Fig.  14. 

This  name  was  proposed  by  the  senior  author  for  the  line  formed  by  the  rupture  of  the 
endyma  along  the  lines  of  its  reflection  from  entocoelian  surfaces.  It  is  a  ragged  edge  of 
endyma,  sometimes  quite  distinct,  as  in  PI.  Ill,  Fig.  7.  The  ripa  may  be  traced  along  the 
Sulci  habenarum  after  removal  of  the  diatela,  along  the  margins  of  the  delta,  along  both 
borders  of  the  rima  and  on  the  thalamus  and  fornix  at  the  nearly  opposite  points  whence 
the  endyma  is  reflected  upon  the  portiplexus.  The  surfaces  separated  by  the  ripa  are 
always  unlike,  the  one  being  entocoelian  and  the  other  ectocoelian. 

§  1314.  Rostrum  {az.),  rm.— Fig.  117  ;  PI.  II,  Fig.  4  ;  PI.  IV,  Fig.  17.  Gray,  A,  623 ; 
Quain,  A,  II,  538. 

The  tip  of  the  genu  of  the  callosum.  It  is  shorter  in  the  cat  than  in  man,  and  some- 
times less  extensive  in  man  than  is  commonly  figured. 

§  1315.   Septum  lucidum  (cerebri),  {az.),  Spt.  /«.— Fig.  113. 

8yn. — Septum  pellucidum,  speculum,  mediastinum  s.  diaphragma  ventriculorum  later- 
alium. 

This  consists  of  two  lateral  halves,  the  hemisepta.  Each  hemiseptum  is  so  much  of 
the  mesal  wall  of  the  procoelia  as  is  intercepted  by  the  callosum  and  the  fornix  when  the 
two  apposed  surfaces  of  the  hemispheres  are  united.  In  man,  although  a  space,  the  pseu- 
doccelia,  remains  between  them  or  is  formed  by  absorption,  the  compound  septum  so  con- 
stituted is  so  thin  as  to  have  received  the  name  lucidum.  In  the  cat  and  in  most  other 
mammals,  the  adjective  is  wholly  inapplicable.  See  hemiseptum  (§  1241)  and  Area  sep- 
talig  (§  1203). 

§  1316.  Splenium  (az),  sp.—Fig.  114,  115,  117  ;  PI.  II,  Fig.  4;  PI.  Ill,  Fig.  6  ;  PI.  IV, 
Fig.  14, 17  ;  §§  1131,  1195,  1238. 

The  rounded  caudal  border  of  the  callosum.  When  the  caudal  portions  of  the  hemi- 
spheres are  separated,  the  splenium  appears  as  a  thick  white  band.  Its  fibers  pass  laterad 
into  the  caudal  portions  of  the  hemispheres.  Its  ventral  surface  is  continuous  with  the 
lyra. 

The  term  is  in  common  use,  but  we  have  not  found  it  in  the  works  of  Gray  or  Quain. 

§  1317.  Stria  longitudinalis  (callosi),  Str.  Ing.—Fig.  115  (?).  Gray,  A,  624 ;  Quain, 
A,  II,  537. 

Spn. — Stria  Lancisi,  nervus  Lancisi. 

The  human  callosum  is  described  as  presenting  several  more  or  less  distinct  longitudi- 
nal lines.  We  have  not  satisfactorily  observed  them  upon  the  fresh  brain  of  either  man  or 
the  cat,  but  presume  .they  are  represented  by  the  longitudinal  striation  vaguely  shown  in 
Fig.  115. 

§  1318.  Striatum  (Corpus),  s.— Fig.  113  ;  PI.  Ill,  Fig.  13  ;  PI.  IV,  Fig.  15, 16 ;  §g  1131 
(14),  1149.     Gray,  A,  625  ;  Quain,  A,  II,  547,  564. 

Syn. — Nucleus  caudatus,  eminentia  lenticularis,  ganglion  cerebri  anterius,  apex  cruris 
meduUse  oblongatse. 

As  indicated  by  the  above  synonymy,  the  corpus  striatum  of  the  older  anatomists 
included  the  entocoelian  ("intraventricular")  portion,  which  appears  in  the  procoelia  (PI. 
IV,  Fig.  16),  and  the  ectocoelian  ("  extra  ventricular")  portion,  which  is  commonly  de- 
scribed as  imbedded  in  the  wall  of  the  hemisphere.  The  former  is  specified  as  Nucleus 
caudatus  and  the  latter  as  Nucleus  lenticularis.     In  man,  between  the  two  is  a  mass  of 


r 


SYNONYMS    AND    REFERENCES.  489 


alba  called  corona  radiata,  and  between  tlie  Nucleus  lenticularis  and  the  insula,  which  lies 
ectad  of  it,  is  a  thin  lamina  of  cinerea,  the  daustrum. 

The  presence  and  arrangement  of  these  divisions  in  the  cat  have  not  yet  been  deter- 
mined by  us,  and  we  have  therefore  i)referred  to  use  the  comprehensive  term  striatum. 
The  student  will  avoid  some  confusion  if  he  bears  in  mind  that  all  of  them  are  portions  of 
the  thickened  proccelian  parietes. 

Spitzka  has  commented  (7,  166)  upon  the  misleading  use  of  the  term  Nucleus  in  this 
connection  ;  we  suggest  that  the  caudate  and  lenticular  portions  of  the  striatum  be  known 
as  (Corpus)  caudatum  and  (Corpus)  lenticulare. 

§  1319.   Sulcus  habenae,  81.  h.—F\g.  122  ;  PI.  Ill,  Fig.  7;  §§  1143,  1156, 1165. 

This  name  was  proposed  by  the  senior  author  (,9,  136  ;  14:,  538,  544)  for  the  more  or 
less  distinct  furrow  along  the  dorso-mesal  angle  of  the  thalamus  just  dorsad  of  the  habena. 
It  coincides  nearly  with  the  line  of  reflection  of  the  diaccelian  endyma  toward  the  oppo- 
site side. 

§  1320.   Sulcus  intercruralis  lateralis,  81.  ic.  ?.— Fig.  118  ;  PI.  Ill,  Fig.  11. 

The  Area  intercruralis  of  the  cat  presents  some  features  which  may  not  exist  in  man 
or  may  have  escaped  notice.  They  are  most  distinctly  visible  when  the  cerebellum  is 
removed  and  the  "  medulla  "  is  dorsiducted  as  in  Fig.  118  and  PI.  Ill,  Fig.  11. 

Caudad  of  the  small  (Locus)  postperforatus  there  is  a  mesal  fissure,  the  8ulcus  intercru- 
ralis mesalis,  and  on  each  side  a  Sulcus  intercruralis  lateralis.  Between  them,  of  course, 
are  two  ridges. 

§  1321.    Sulcus  intercruralis  mssalis,  81.  ic.  ms. — See  §  1330. 

§  1322.   Sulcus  limitans,  81.  li.—F\g.  121 ;  PI.  Ill,  Fig.  13;  §§  1149,  1155. 

This  name  was  proposed  provisionally  by  the  senior  author  (.9,  137  ;  14,  538)  for  the 
"  depression  between  the  thalamus  and  the  striatum  "  (Gray,  A,  625  ;  Quain,  A,  II,  549), 
which  is  obvious  and  usually  mentioned,  but  has  apparently  not  been  named.  So  long  as 
both  the  bodies  above  mentioned  are  regarded  as  parts  of  the  procoelian  floor,  this  farrow 
might  not  require  special  designation  any  more  than  the  furrow  between  the  fornix  and 
the  hypocampa.  But,  in  the  cat  at  least,  "  this  furrow  is  the  line  of  separation  between 
the  entoccelian  surface  of  the  striatum  and  the  ectocoelian  surface  of  the  thalamus.  A 
shorter  term  is,  however,  desirable." 

§  1323.   Sulcus  triradiatus  {az.),  81.  trd.—F\g.  118  ;  PI.  Ill,  Fig.  11  ;  §  1169. 

This  name  was  proposed  by  the  senior  author  {14:,  554)  for  the  three-pointed  shallow 
depression  which  demarcates  the  albicantia  from  each  other  and  from  the  Tuber  cinereum. 
It  is  much  deeper  in  the  human  brain. 

§  1324.  Terma  {az.),  t.~F\g.  110-112,  117  ;  PI.  II,  Fig.  4  ;  PI.  IV,  Fig.  16.  Gray, 
A,  620  ;  Quain,  A,  II,  536. 

8yn. — Lamina  terminalis  s.  cinerea. 

The  thin  lamina  between  the  prsecommissura  and  the  chiasma  and  crista,  and  forming 
the  cephalic  boundary  of  the  ventral  portion  of  the  aula. 

The  name  was  proposed  by  the  senior  author  (.9,  137 ;  14,  541)  as  a  brief  and  signifi- 
cant substitute  for  the  compound  terms  commonly  employed.  It  is  the  termination  of  the 
mesal  series  of  cceliae,  and  therefore  has  considerable  morphological  significance  ;  but  it  is 
so  delicate  as  to  be  sometimes  overlooked,  and  is  usually  ruptured  in  the  extraction  of  the 
human  brain. 

§  1325.  Thalamus,  th.— Fig.  110-113,  117,  122,  123;  PI.  II,  Fig.  4;  PI.  Ill,  Fig.  6,  7, 
9,10,13;  PI.  IV,  Fig.  16,  18,  19;  §§  1143,  1144,  1156,  1157.  Gray,  A,  629;  Quain,  A. 
II,  535. 


490  A NA  TOMICAL     TECHNOL 0  G  Y. 

Syn. — Thalamus  opticus,  thalamus  nervi  optici,  ganglion  cerebri  posticum,  eminentia 
magna  cerebri. 

The  thalami  form  the  walls  (lateral  parietes)  of  the  diacoelia,  and  are  connected  by  the 
medicommissura. 

Most  of  the  important  features  of  the  thalami  are  described  in  the  sections  referred  to  ; 
there  is  one,  however,  which  may  properly  be  insisted  upon  here,  inasmuch  as  it  is  not 
commonly  recognized  ;  viz.,  its  complete  exclusion  from  the  procmlia  in  the  cat. 

In  most  works  upon  Descriptive  Anatomy,  the  thalami  are  mentioned  as  appearing  in 
the  "  lateral  ventricles,"  and  in  Gray  (A,  Fig.  364)  and  Quain  (A,  II,  Fig.  383),  the  surfaces 
of  the  striata  and  thalami  are  apparently  similar  and  continuous.  Now  the  fornix  (including 
the  hypocampae  and  fimbriae)  of  man  is  relatively  narrower  than  that  of  the  cat,  and  it  is 
quite  possible  that  in  the  adult,  even  without  the  ruptare  of  the  membranes  at  the  rima, 
a  part  of  the  dorsal  aspect  of  the  thalamus  may  appear  in  the  proccelia  ;  if  so,  however, 
that  part  of  the  surface  must  be  covered  by  the  procoelian  endyma,  and  the  line  of  reflec- 
tion (ripa)  upon  the  proplexus  should  be  represented.  Upon  these  points  our  materials 
for  observation  do  not  enable  us  to  speak  more  fully. 

But  in  the  cat  and  dog,  we  are  prepared  to  state  emphatically  (§  1083),  that  the  mar- 
gins of  the  rima  are  in  close  apposition,  excepting  for  the  intruded  dements  of  the  proplexus, 
and  that  in  these  animals  and  in  other  mammals  examined  by  us,  no  portion  of  the  thala- 
mus appears  in  the  proccelia  or  enters  into  the  formation  of  its  floor ;  any  statements  to 
tbe  contrary  should  not  be  accepted  without  detailed  descriptions  and  figures. 

§  1326.  Tractus  opticus,  Tr.  op.—F\g.  116,  118;  PI.  II,  Fig.  3;  PI.  Ill,  Fig.  9,  11  ; 
§  1144.     Gray,  A,  638  ;  Quain,  A,  II,  533. 

The  subcylindrical  fibrous  band  which  arises  from  the  diencephalon,  and  perhaps  from 
the  mesencephalon,  and  meets  its  platetrope  cephalad  of  the  Tuber  cinereum  to  form  the 
chiasma.  The  larger  part  of  the  tract  seems  to  be  a  direct  continuation  of  the  praegenicu- 
latum,  but  we  have  not  traced  the  fibers  in  detail.     See  Cliap.  XI. 

§  1327.   Tractus  postrhinalis,  Tr.  prh.—F]g.  116  ;  PI.  I,  Fig.  2  ;  PI.  II,  Fig.  3. 

This  and  the  following  name  were  proposed  by  the  senior  author  for  the  caudal  and 
cephalic  portions  of  the  ventral  aspect  of  the  prosencephalon  and  rhinencephalon,  bounded 
latero-dorsad  by  the  F.  postrhinalis  and  F.  rhinalis  respectively.  They  are  of  course  con- 
tinuous with  each  other. 

In  the  adult  human  brain  these  tracts  are  relatively  so  small  and  so  obscured  by  the 
overhanging  convolutions  of  the  hemisphere  proper  that  they  appear  not  to  have  been 
defined. 

Tractus  rhinalis,  Tr.  rh.—See  §  1327. 

§  1328.  Trapezium,  tz.-Fig.  116  ;  PI.  I,  Fig.  2  ;  PI.  II,  Fig.  3  ;  §§  1140,  1161,  1276. 
Quain,  A,  II,  511. 

Syn. — Corpus  trapezoides — Meynert  (Strieker,  A,  726) ;  Huxley,  A,  64. 

The  quadrangular,  slightly  convex  portion  of  the  Area  postpontilis  in  the  angle  formed 
by  the  caudal  margin  of  the  pons  and  the  lateral  margin  of  the  pyramis.  It  is  sometimes 
crossed  by  a  faint  cephalo-caudal  band,  as  indicated  on  the  right  (left  of  the  figure)  side  of 
PI.  II,  Fig.  2.  This  band  seems  to  be  continuous  with  the  Area  oralis,  and  there  is  some- 
times (as  in  Prep.  407,  M.  C.  U.)  an  equally  distinct  band  close  to  the  pyramis  and  appar- 
ently continuous  with  the  Area  elliptica. 

Laterad,  the  trapezium  is  continuous  with  the  Eminentia  auditoria ;  the  N.  abducens 
arises  between  it  and  the  pyramis,  and  the  N.  facialis  between  the  pons  and  its  latero- 
cephalic  angle. 

In  man  this  area  is  covered  by  the  greater  caudal  extension  of  the  pons. 


Sr.YONYJIS    AND    REFERENCES.  491 

§  1329.  Tuber  cinereum  {az.\  T.  dn.—F\g.  Ill,  112,  116-118,  122  ;  PI.  II,  Fig.  3,  4; 
PL  III,  Fig.  5,  9, 11 ;  §  1074  (E).     Gray,  A,  621  ;  Quain,  A,  II,  535. 

The  gray  eminence  at  the  cephalic  part  of  the  Area  cruralis  just  caudad  of  the  chiasma. 
To  it  is  attached  the  hypophysis  by  the  infundibulum  which  covers  the  mesal  Foramen 
infundibuli.  The  Tuber  cinereum  is  really  continuous  with  the  terma,  but  the  chiasma 
forms  an  ectal  interruption. 

§  1330.   Tuberculum  Rolando,  nd.  Bol.—%  1190.     Gray,  A,  613;  Quain,  A,  II,  510. 
According  to  the  American  Jour,  of  Neurology,  etc.  (1, 102),  the  elevation  herein  named 
Area  ovalis  is  homologous  with  the  Tuberculum  Rolando  or  Tubercolo  cinereo. 

§  1331.  Valvula  {nz.),  m— Fig.  111-114, 117:  PI.  II,  Fig.  4;  PI.  Ill,  Fig.  7  ;  §§  1141, 
1165.     Gray,  A,  631 ;  Quain,  A,  II,  552. 

Syn. — Valvula  Vieussenii,  vv.  cerebelli,  vv.  Willisiana,  vv.  magna  cerebri,  velum 
interjectum  cerebelli,  velum  medullare  anticum. 

The  delicate  and  transparent  roof  of  the  longer  and  cephalic  portion  of  the  epicoelia. 
Cephalad  it  is  continuous  with  the  postoptici,  and  caudad  with  the  cerebellum  just  cepha- 
lad  of  the  highest  part  of  the  epicoelia.     Near  its  cephalic  end  arise  the  NN.  trochleares. 

We  have  not  ascertained  whether  the  valvula  is  covered  by  a  fold  of  pia  ;  apparently 
there  is  between  it  and  the  overhanging  cerebellum  only  a  little  connective  tissue.  Neither 
do  we  know  the  precise  constitution  of  the  delicate  substance  of  the  valvula ;  it  is  so  thin 
that  it  might  well  be  included  with  the  other  telae  as  the  epitela. 

%  1332.  Velum  (interpositum),  {az.\  tl.—F'ig.  122  ;  g§  1142,  1144, 1156.  Gray,  A,  628  ; 
Quain,  A,  II,  545. 

As  has  been  admitted  elsewhere,  our  knowledge  of  the  velum  is  incomplete,  especially 
in  respect  to  its  relation  with  the  diatela.  As  commonly  described,  and  as  appears  to  be 
the  case  in  the  cat,  it  is  the  fold  of  pia  between  the  dorsal  aspect  of  the  mesencephalon 
and  diencephalon  and  the  ventral  aspect  of  the  superincumbent  fornix,  a  part  of  the  pros- 
encephalon. Theoretically,  and  doubtless  actually  in  the  embryo  mammal,  the  two  layers 
of  this  fold  are  simply  continuous  at  the  line  of  junction  of  the  prosencephalon  with  the 
diencephalon  ;  but  the  growth  of  the  former  and  its  recumbency  upon  the  latter  brings 
them  into  contact,  and  perhaps  their  distinction  is  altogether  lost. 

Primarily,  too,  the  diencephalic  layer  must  have  been  in  contact  with  the  primitive 
roof  of  the  diacoelia  and  entered  into  the  formation  of  the  diatela  ;  but  the  close  approxi- 
mation and,  perhaps,  fusion  of  the  two  layers  in  the  adult  renders  it  possible  to  remove 
them  together,  and  the  diatela  which  remains  must  consist,  therefore,  of  merely  the 
endyma  with  the  atrophied  nervous  substance  of  the  roof. 

The  relations  of  the  velum  to  the  proplexus  are  referred  to  in  §  1295. 

§  1333.  Vermis  (cerebelli),  («s.),  -ym.— Fig.  114 ;  PI.  I,  Fig.  1,  2  ;  PL  IV,  Fig.  15  ;  §  1200. 
Huxley,  A,  64. 

Syn. — Lobus  medius  cerebelli. 

The  name  vermis  seems  to  be  used  in  anthropotomy  in  a  restricted  sense  for  a  portion 
of  the  median  lobe  of  the  cerebellum,  but  Huxley  designates  by  it  the  entire  lobe. 

In  the  adult  cat  the  vermis  is  markedly  contorted,  although  regular  and  symmetrical 
in  the  new-born  kitten  (Wilder,  1 1 ,  PL  I,  Fig.  2). 

§  1334.  Other  Figures  of  the  Brain  of  the  Cat  or  other  Felidae. — The  following 
list,  arranged  alphabetically  according  to  the  names  of  the  authors,  includes  all  the  works 
and  papers  known  to  us  to  contain  figures  of  feline  brains.  Additions  and  corrections 
will  be  thankfully  received.  The  figures  represent  the  cat's  brain  unless  otherwise 
specified. 


492  ANA  TOMICAL     TECHNO  LOGY. 

(I)  Bell,  T.  :  A,  Fig.  201  ;  tlie  dorsal  and  dextral  aspects  of  the  brain  of  "  the  lion." 
The  lateral  aspect  represents  a  brain  so  distorted  as  to  be  unrecognizable  ;  the  dorsal 
aspect  is  evidently  of  a  cat's  brain,  and,  although  very  imperfect,  is  copied  by  Owen,  A,  III, 
Fig.  83. 

(3)  Bourgery  et  Jacob  :  A,  VIII,  PI.  16 ;  Fig.  1,  ventral  aspect  of  myelon  and  its 
nerves  and  of  the  caudal  portion  of  the  brain  ;  Fig.  2,  dorsal  aspect  of  the  myelencephalon. 
In  Fig.  1,  some  features  are  obviously  incorrect.     Both  are  apparently  original. 

(3)  Cuvier  (Audouin,  etc.) :  B,  II,  PI.  Ill,  Fig.  6  ;  dorsal  aspect  of  the  brain  of  the  lion, 
reduced.     "  Tiree  de  I'atlas  de  M.  Leuret  "  [Leuret  et  Gratiolet,  A]. 

(4)  Dareste  :  13,  PI.  2;  Fig.  3,  lateral  aspect  of  right  hemisphere;  Fig.  4,  dorsal 
aspect  of  hemispheres.  Diagrams,  not  wholly  correct,  of  the  fissures.  Apparently 
original. 

(5)  Ferrier  :  A,  Fig,  34,  35  ;  dorsal  and  lateral  aspects,  with  the  "  motor  areas  " 
marked  upon  the  latter.  The  figures  are  original  and  correct ;  respecting  the  enumera- 
tion of  the  external  convolutions,  see  §  1364. 

(6)  Flower  :  6,  PI.  27  ;  Fig.  12,  the  mesal  aspect  of  the  right  hemisphere.  Correctly 
represents  the  mesal  fissures  excepting  part  of  the  hypocampal  ;  original. 

(7)  Gall  and  Spurzheim  :  A  ;  according  to  Owen  (35,  135),  the  cat's  brain  is  figured 
in  this  work. 

(8)  Gegenbaur  (Lankester) :  A ;  Fig.  286,  C,  represents  a  partially  dissected  cat's 
brain  ;  the  figure  is  evidently  original,  but  vague  in  some  respects. 

(9)  Gervais,  P.  :  14(5  ;  there  are  several  figures  of  feline  brains,  but  the  work  is  not 
at  present  accessible  to  us,  and  they  cannot  be  specified. 

(10)  Hammond,  G.  M.  :  1,  Fig.  1  ;  a  transection  of  the  left  hemisphere  through  the 
striatum.     This  original  figure  is  intended  to  display  certain  histological  features. 

(II)  Hitzig  :  A,  Fig.  7;  the  lateral  aspect ;  a  fissural  diagram. 

(12)  Jones,  T.  R. :  A,  Fig.  411 ;  the  ventral  aspect  of  the  lion's  brain.  Reduced 
nearly  one  balf,  and  rev^ersed,  from  Tiedemann,  A,  PI.  Ill,  Fig.  4  ;  unacknowledged. 

(13)  Leuret  (Leuret  et  Gratiolet,  A,  PI.  V) :  dorsal  and  lateral  aspects  of  the  brain  of  a 
lion  and  lateral  aspect  of  that  of  a  panther.  Fig.  1-3,  dorsal,  mesal  and  lateral  aspects  of 
the  cat's  brain.  All  are  obviously  original  and  very  correct,  excepting  some  of  the  struc- 
tural features  of  Fig.  2,  especially  the  relations  of  the  fornix  and  callosum. 

(14)  Lussana  e  Lemoigne  :  A  ;  Fig.  123-125,  the  mesal  aspect  of  the  left  hemi- 
sphere, with  two  schematic  diagrams  ;  Fig.  126-131,  tho  dorsal,  ventral  and  lateral  aspects 
of  the  hemispheres,  actual  and  schematic  ;  Fig,  132-135,  the  ventral,  mesal,  dorsal  and 
lateral  aspects  of  the  hemispheres  of  a  leopard. 

(15)  Marshall,  J.  :  A,  Fig.  2 ;  dorsal  aspect ;  poor. 

(16)  Meynert,  T.  :  ^  :  Fig.  8,  17,  dorsal  and  lateral  aspects  of  the  hemispheres  of  a 
lion  ;  Fig.  16,  lateral  aspect  of  the  hemisphere  of  a  wild-cat  ;  Fig.  23,  the  lateral  aspect  of 
a  lion's  hemisphere.     The  figures  are  original,  clear  and  correct. 

(17)  Mivart:  B,  Fig.  125,  126,  129:  the  lateral,  dorsal  and  mesal  aspects.  These 
figures  are  unacknowledged,  but  evidently  copied  from  Leuret,  PI.  V.  Fig.  1-3  ;  the  inac- 
curate representation  of  the  pseudoccelia  is  exaggerated. 

Fig.  127  is  an  apparently  original  representation  of  a  preparation  made  by  tilting  the 
cerebellum  caudad  and  the  hemispheres  cephalad.  as  in  Fig.  114  of  this  work,  so  as  to 
expose  the  optici,  thalami,  etc.  A  very  erroneous  impression  is  given  by  the  exposure  of 
the  striata  and  the  introduction  of  a  tubular  and  wholly  imaginary  pseudoccelia. 

Fig.  128,  the  ventral  aspect  of  what  purports  to  be  the  brain  of  a  cat ;  aside,  however, 
from  the  general  outline  and  the  exposure  of  the  trapezium,  it  might  be  the  brain  of  a 
monkey,  and  some  of  its  features  have  never  been  observed  in  the  cat. 


OTHER    FIGURES    OF    THE    BRAIN.  493 

(18)  Owen  :  25,  PI.  20 ;  Fig.  1-3,  dorsal,  lateral  and  mesal  aspect  of  the  brain  of  the 
Clieetah  Felis  jubata,  shaded  ;  Fig.  4-6,  the  same  of  the  cat,  outline.  The  former  are 
somewhat  vague,  especially  as  to  the  Sylvian  fissure  ;  the  latter  are  clear,  and  correct 
excepting  the  non-extension  of  the  F.  postrhinalis  in  Fig.  5,  and  the  indication  upon  Fig,  6 
of  an  improbable  fissure  near  the  caudal  end  of  the  hemisphere. 

(19)  Owen  :  A,  III  ;  Fig.  83,  dorsal  aspect  of  cat's  brain.  Unacknowledged,  but  evi- 
dently copied  from  the  very  poor  figure  of  Bell  (A). 

(20)  Owen  :  A,  III  ;  Fig.  86,  the  mesal  aspect  of  the  right  hemisphere ;  apparently 
original.  A  good  outline  diagram,  excepting  the  presence  of  the  line  marked  (13),  pur- 
porting to  represent  the  F.  lamhdoidalis,  and  apparently  tlie  same  as  shown  in  Fig.  3  and  6. 
Whether  or  not  such  a  fissure  exists  in  the  Cheetah,  or  whether,  if  present  in  any  feline 
brain,  it  is  the  homologue  of  the  "  lambdoidal  "  or  "  occipi to-parietal  "  fissure,  need  not  be 
discussed  here ;  but  among  the  many  (over  200)  cat's  brains  examined  by  us,  none  have 
presented  any  fissure  in  that  region.  Probably  the  line  was  accidentally  introduced  or 
may  represent  a  vascular  furrow  (§  1341). 

(21)  Owen:  A,  III;  Fig.  91,  the  lateral  aspect;  an  outline  diagram,  apparently 
reduced  and  slightly  changed  from  the  same  author's  Fig.  5  (25,  PI.  20').  The  superorbi- 
talis,  however.  Las  disappeared,  and  the  diagmalU  is  made,  incorrectly,,  to  join  the  rhinalis. 

(22)  Pansch  :  J,  Taf.  XIV,  XV  ;  Fig.  23-38,  dorsal,  lateral  and  mesal  aspects  of  the 
hemispheres  of  adult,  new-born  and  fcetal  cats.  These  are  excellent  original  diagrams  of 
the  fissures. 

(23)  Serres  :  A,  PI.  XIV  ;  Fig.  264,  265,  the  lateral  and  dorsal  aspects  of  what  pur- 
ports to  be  the  brain  of  a  lion,  but,  as  remarked  by  Leuret  (Leuret  et  Qratiolet,  A,  PI.  5, 
p.  10),  is  really  that  of  a  cat. 

(24)  Spurzheim  :  A,  PI.  IV  ;  Fig.  5,  dorsal  aspect  of  a  somewhat  distorted  brain. 

(25)  Stowell,  T.  B.  :  1  \  Fig.  1,  2,  ventral  and  lateral  aspects  of  the  cat's  brain,  with 
special  reference  to  the  ectal  origins  of  the  cranial  nerves  ;  the  fissures  and  ether  parts 
are  shown  diagrammatically  ;  Fig.  3-12,  ectal  nerve  origins  and  distribution  of  the  vagus. 

(26)  Tiedemann,  F.  :  A,  Tab.  Ill  ;  Fig.  3-5,  doreal^  ventral  and  mesal  aspects  of  a 
lion's  brain  ;  original  and  mainly  accurate  ;  Fig.  6,  the  brain  "  Felis  nondum  adulti,  quod 
cerebro  Laonis  persimlle  est."  Unless  the  author  had  positive  knowledge  as  to  the  imma- 
turity of  this  brain,  it  must  be  regarded  as  that  of  an  adult  domestic  cat. 

(27)  Wilder  :  11  ;  PI.  I,  Fig.  1,  2,  portions  of  the  cerebellum,  showing  the  xermis 
and  the  Lobulus  appendicular  is ;  PI.  Ill,  Fig.  15,  17,  dorsal  and  lateral  aspects  of  the 
hemispheres,  diagrams  of  the  fissures ;  PI.  IV,  Fig.  18,  19,  lateral  aspect,  young  Asiatic 
and  African  lions,  fissural  diagrams. 

(28)  Wilder  :  8  ;  Fig.  1,  2,  fissural  diagrams  of  the  lateral  and  mesal  aspects. 

(29)  Wilder:  Jf4;  PI.  1-3,  Fig.  1-5,  the  dorsal,  lateral,  ventral,  mesal,  cephalic  and 
caudal  aspects  of  the  entire  brain  or  of  the  hemispheres  ;  PI.  3,  4»  Fig.  7-20,  sections  and 
dissections  illustrating  the  gross  anatomy. 

THE  CEREBRUM  AND   ITS  FISSURES. 

§  1335.  Form  of  the  Cerebrum.— As  compared  with  that  of 
most  dogs,  the  cat's  cerebrum  is  remarkable  for  its  width.  The 
average  width  is  34-37  mm.  With  four  well  preserved  adult  brains, 
taking  the  width  at  100  as  the  standard,  the  lengths  were  respect- 
ively 93,  97,  100  and  103,  while  the  heights  were  75,  67,  71  and  72. 
In  round  numbers,  then,  the  lateral  and  longitudinal  dimensions  of 


494 


ANATOMICAL    TECHNOLOGY, 


the  combined  hemispheres  are  approximately  equal,  and  the  height 
is  about  three  fourths  as  much. 

As  compared  with  most  dogs,  also,  the  region  cephalad  of  the 
cruciate  fissure  is  very  short. 

THE  CEREBRAL  FISSURES. 

§  1336.  Beferences. — The  principal  works  and  papers  in  which  the  cerebral  fissures  are 
treated  of  are  named  in  connection  with  the  synonymy  of  the  F.  cruciata  (§  1361). 

§  1337.  As  was  remarked  in  §  1131  (17,  18),  the  brain  of  the  cat  differs  from  that  of 
the  Amphibia  in  that  the  hemispheres  and  cerebellum  are  not  only  larger  in  proportion, 
but  convoluted — the  surface  presenting  depressions  {fissurcB)  and  intervening  folds  igyri). 

The  cerebellar  fissures  are  numerous  and  apparently  irregular  ;  and  we  are  not  aware 
that  their  arrangement  has  been  studied  in  detail. 

The  cerebral  fissures  are  comparatively  few  (about  30)  and  simple,  so  that  it  is  not 
diflBcult  to  delineate  or  describe  them  as  they  appear  upon  a  given  brain. 

§  1338.  The  fissures  should  be  studied  before  the  gyri. — Notwithstanding  the  prob- 
ability that  the  fissures  are  only  the  resxilts  of  the  outgrowth  constituting  the  gyri,  and 
the  fact  that  experiments  are  made  upon  the  exposed  surfaces  of  the  latter,  the  study  of 
cerebral  topography  should  begin  with  the  fissures,  and  they  should  be  identified  and 
named  before  the  gyri  are  described  and  designated.  As  remarked  by  the  senior  author 
(11,  219),  the  "  sides  of  a  fissure  are  usually  near  together  and  parallel,  so  that  the  fissure 
may  be  described  as  a  single  line  of  certain  direction  ;  but  the  opposite  borders  of  any  one 
gyrus  are  rarely  parallel  throughout  their  whole  extent.  Indeed,  it  would  be  as  hard  to 
designate  gyri  without  first  identifying  fissures  as  to  describe  the  countries  of  Europe 
without  mentioning  its  rivers." 


Fig.  124,  125. — Diagrams  op  the  Lateral  and  Mesal  Aspects  of  the  Hemi- 
spheres,  SHOWING  THE  FiSSURES  ;    X  1.5. 


Fig.  124. — Diagram  of  the  lateral  aspect  of  the  left  hemisphere,  showing  the  fissures; 
xl.5. 

Fig.  125. — Diagram  of  the  mesal  aspect  of  the  right  hemisphere,  showing  the  fissures. 
The  diencephalon  and  the  segments  caudad  of  it  have  been  removed  as  in  PI.  IV,  Fig.  17, 
so  as  to  expose  the  F.  hypocampce  and  the  adjacent  parts  ;    x  1.5. 

On  both  the  figures  too  little  distinction  is  indicated  between  the  constant  and  the 
inconstant  fissures.  Upon  the  Table  (p.  496)  the  former  are  printed  in  heavier  faced  type, 
and  they  are  enumerated  in  §  1366. 


STUDY    OF    THE    FISSURES.  '  495 

§  1339.  Study  of  the  Fissures. — The  student  should  make  outline  drawings  of  one 
or  more  hemispheres,  especially  of  the  lateral  aspect.  If  possible,  both  hemispheres  of 
the  same  brain  should  be  drawn  and  compared  with  respect  to  the  amount  and  character 
of  lateral  variation  and  compensation  (Wilder,  11,  232).  The  sex  should  always  be 
noted,  and  the  age,  known  or  estimated,  stated  upon  the  drawing. 

The  drawiopfs  of  fissures  should  be  in  outline  only,  and  most  attention  should  be  given 
to  the  union  or  independence  of  fissures  which  approach  each  other. 

fcji  1840.  Sometimes  it  is  diificult  to  distinguish  between  a  true  fissure  and  a  depression 
in  which  was  lodged  a  superficial  vessel.  Such  vascular  trenches,  however,  have  usually 
more  abrupt  and  sharply  denned  edges  than  the  fissures  (Wilder,  11,  221). 

The  mesal  aspect  of  the  hemisphere  is  largely  a  plane  surface  ;  but  the  lateral  and 
other  aspects  present  difficulties  in  respect  to  perspective  which  are  common  to  convex 
surfaces.  Where  a  hemisphere  is  very  peculiar,  the  drawings  should  be  based  upon  pho- 
tographs. The  method  of  drawing  fissures  described  by  the  senior  author  in  1873  (11, 
219),  in  which  the  perspective  was  iprnored,  is  no  longer  recommended  by  him. 

§  1341.  Indicating  the  Relative  Depth  of  Fissures. — As  appears  in  Fig.  122,  and  in  PI. 
Ill,  Fig.  13,  and  PL  IV,  Fig.  15,  the  fissures  vary  considerably  in  depth.  They  also  vary 
in  different  parts  of  their  course,  being  usually  deepest  near  the  middle  of  their  length. 
Wh'^re  a  fissure  is  wholly  superficial,  it  may  be  represented  by  a  shading  ;  but  otherwise 
a  liu3  must  be  employed,  the  width  of  which  may  indicate  the  depth  of  the  fissure  in  dif- 
ferent parts  of  its  extent  and  as  compared  with  other  fissures.  The  depth  may  be  apcer 
tained  by  carefully  "  sounding"  with  a  graduated,  thin,  smooth  and  rounded  rule,  or  by 
sections  of  the  brain  after  the  location,  extent  and  connection  of  the  fissures  have  been 
indicated  by  lines  of  uniform  width. 

§  1342.  Table  of  the  Cerebral  Fissures.— The  accompanying  Table  (p.  496)  includes 
an  alphabetical  list  of  the  feline  cerebral  fissures,  with  the  abbreviations  employed  in 
this  work,  and  the  principal  synonyms. 

The  constant  fissures  are  printed  in  black  letter. 

The  synonymy  is  limited  to  writers  who  have  made  special  additions  to  the  technical 
nomenclature,  and  excludes  those  who  have  employed  phrases  or  vernacular  names,  or 
who  have  used  the  names  of  other  writers  in  purely  physiological  papers. 

§  1343.  Sources  of  the  Names. — The  following  brief  statement  respecting  the  names  is 
quoted  from  the  senior  author's  paper  {8,  50) : — 

•'Owen's  ' postsylvian' ^la.o\\\A  not  be  displaced  by  Krueg's '«i/pr«s2^?m  j90S^m(9r,' nor 
his  '  marginal '  hy  '  supra splenialis.'  Likewise,  Flower's  '  sujwaorhitaV  has  priority  ever 
my  ' presylman'  which  Krueg  has  adopted  [and  is  free  from  the  implication  of  a  doubt- 
ful homology]. 

"  On  the  other  hand,  Krueg's  *  anterior '  and  '  postica '  are  so  much  more  usable  than 
previous  names  as  to  be  worthy  of  acceptance,  especially  as  they  may  be  regarded  as 
abbreviations  of  the  phrases  by  which  the  fissures  in  question  were  designated  by  Owen 
and  myself.  *  Splenialis  '  is  to  be  preferred  to  supercallosal  or  calloso-marginalis,  so  long 
as  the  human  homologue  of  the  fissure  is  uncertain.  If  marginalis  is  to  be  retained,  post- 
marglnalis  will  be  better  than  *  postspleniaHs.' 

"  I  am  particularly  gratified  to  find  that  Krueg  admits  as  fissural  integers  the  ansata 
and  the  diagonalis  ;  the  former  I  had  intended  to  call  transversa  and  the  latter  intermedia, 
but  Krueg's  names  must  be  retained.  We  agree  also  in  regarding  Owen's  *  medilateral' 
as  composed  of  two  fissures,  which  Krueg  terms  medilateral  and  eonfinis.  I  had  intended 
to  leave  Owen's  name  attached  to  the  fissure  which  is  really  mesad  of  the  lateralis  and  to 
call  the  [caudal]  curved  division  lunata ;  the  name  lunata  has  now  been  given  to  what 
otherwise  would  have  been  sublunatn.  I  have  applied  the  name  intermedia  to  a  fissure 
which  Krueg  mentions  but  does  not  name." 


496 


ANA  TOMICAL    TECHNO L  OGT. 


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-     g 

S 

FORMATION    OF   FISSURES.  497 

§  1344.    Problems  Connected  with  the  Cerebral  Fissures. — 

The  study  of  the  fissures  of  a  single  brain  is  comparatively  uninter- 
esting and  unprofitable  unless  three  general  questions  are  consid- 
ered : — 

! 

(1)  What  relations  do  tlie  fissures  bear  to  the  ental  structures? 

(2)  What  is  the  fissural  pattern  in  the  cat  ? 

(3)  How  do  the  fissures  of  the  cat  compare  with  those  of  man  and  other  mammals  ? 

§  1345.  Formation  of  Fissures. — At  birth  the  cat's  hemispheres  present  fewer  and 
shallower  fissures  than  in  the  adult.  Presumably  they  were  entirely  smooth  at  an  earlier 
period,  as  is  the  case  in  all  other  mammals  which  have  been  examined. 

The  hypocampal  fissure  represents  an  involution  of  the  entire  thickness  of  the  parietes, 
the  hypocampa  (§  1243)  being  the  reverse  elevation.  The  callosal  fissure,  and  perhaps 
some  of  the  others  already  enumerated  (§  1343),  are  formed  in  some  peculiar  way. 

So  far  as  the  other  and  ordinary  fissures  are  concerned,  although,  sometimes  described 
as  depressions,  it  is  probable  that  they  are  to  be  regarded  as  lines  of  less  elevation  as  com- 
pared with  the  intervening  folds.  More  extended  and  accurate  observations  are  needed 
upon  this  matter.     For  the  formation  of  the  cruciate  fissure,  see  §  1359. 

§  1346.  Structural  Relations  of  Certain  Fissures. — So  far  as  appears  from  sections 
of  the  cat's  brain  at  any  period  after  birth,  only  eight  of  the  cerebral  fissures  have  any 
intimate  or  constant  relation  to  structural  features,  viz. ,  the  callosal,  fimhrial,  hypocampal, 
olfactoria,  postradical,  prceradical,  rhinalis  and  postrhinalls.  These  have  all  been  men- 
tioned in  connection  with  the  parts  with  which  they  appear  to  be  correlated. 

§  1347.  In  man  two  other  fissures,  which  do  not  exist  in  the  cat,  are  related  to  ental 
structures  :  the  calcarine  to  the  calcar  (§  1194)  and  the  collateral  to  the  Eminentia  collat- 
eralis  at  the  place  of  dej^arture  of  the  postcornu  from  the  medicornu. 

A  few  of  the  fissures  will  now  be  mentioned  separately. 

§  1348.  F.  callosalis,  F.  cl,  the  callosal  fissure.— Pig.  117,  122,125;  PI.  II,  Fig.  8; 
PI.  Ill,  Fig.  18 ;  PL  IV,  Fig.  17,  20. 

This  coincides  with  the  dorsal  border  of  the  callosum,  curves  about  the  splenium  to 
join  the  hypocampal  (Fig.  125)  and  about  the  genu  to  be  continuous  with  the  F.  prceradi- 
calis  when  the  latter  is  distinct. 

§  1349.  F.  fimbriae,  F.  fmh.,  the  fimbrial  fissure.— Fig.  121,  125;  PI.  IV,  Fig.  14,  17; 
§  1172. 

A  distinct  and  apparently  constant  depressed  line  between  the  fasciola  and  the  fimbria, 
thus  coinciding  with  the  margin  of  the  cinerea.  It  is  not  a  true  cortical  fissure,  and 
perhaps  should  not  be  enumerated  with  the  rest. 

§  1350.  F.  hypocampae,  F.  hmp.,  hvpocampal  fissure.— Fig.  121, 125  ;  PI.  IV,  Fig.  14, 
17 ;  §  1172. 

Syn. — F.  hippocampi,  hippocampal  fissure. 

This  is  not  the  deepest  of  the  cerebral  fissures,  but  it  is  one  of  the  longest,  and  is  per- 
haps the  most  corfstant  of  all  among  the  Mammalia,  being  present  when  the  hemispheres 
are  otherwise  smooth  or  indented  only  by  the  rhinalis  and  postrhinalls. 

It  extends  from  near  the  tip  of  the  Ldbulus  hypocampm  to  the  Hplenium,  where  it  is 

continuous  with  the  F.  callosalis.     In  the  larger  part  of  its  course  it  presents  a  decided 

caudal  convexity,  forming  nearly  the  half  of  a  circle  and  coinciding  in  general  with  the 

medicornu  and  with  the  hypocampa,  of  which  it  is  the  depression  in  reverse.     Near  the 

32 


498  ANATOMICAL    TECHNOLOGY, 

splenium,  however,  it  presents  a  short  and  quite  sharp  cephalic  convexity.     The  cinerea 
cephalad  of  the  F.  hypocampm  constitutes  i\xQ  fasciola. 

§  1351.  F.  Sylviana,  F.  8.,  the  Sylvian  fissure.— Fig.  124  ;  PI.  I,  Fig.  2 ;  PI.  II, 
Fig.  3  ;  PI.  Ill,  Fig.  5  ;  §  1163. 

8yn. — Fissura  Sylvii  ;  the  "  posterior  "  or  longer  branch  of  the  human  F.  Sylvii. 

By  common  consent,  this  short  and  distinct  fissure  of  the  cat  and  dog  is  called  by  the 
name  originally  applied  to  the  much  more  extensive  and  complex  human  fissure.  To  dis- 
cuss the  homology  would  occupy  undue  space.  The  chief  questions  are  (1)  as  to  the  rep- 
resentation of  the  insula  (§  1247),  which  in  man  is  concealed  between  the  dorso-cephalic 
and  the  ventro-caudal  lips  of  the  fissure  ;  and  (2)  as  to  the  correspondence  of  the  relatively 
extensive  region  between  the  F.  Sylviana  and  the  F.  superorbitalis  with  the  human  oper- 
culum ;  Meynert,  1,  Fig.  16;  Wilder,  11,  225,  and  14,  551. 

§  1352.  The  statement  (11,  223)  of  the  senior  author  as  to  the  presence  of  the  Sylvian 
fissure  in  all  brains  which  are  fissured  at  all  (quoted  in  the  last  two  editions  of  Dalton's 
Physiology,  A,  413)  referred  originally  only  to  the  lateral  fissures,  and  may  not  be  correct 
with  even  that  qualification,  for  the  rhinalis  and  postrhinalis  seem  to  occur  in  some  mam- 
mals when  the  Sylvian  is  either  absent  or  very  indistinct. 

§  1353.   Fissura  ansata,  F.  an.—F\g.  24 :  PI.  I,  Fig.  1,  2. 

This  fissure  is  peculiar  and  presents  some  diflBculties.  Most  commonly  it  seems  to 
form  simply  a  conjunction  between  the  lateralis  and  the  coronalis,  with  a  branch  pointing 
meso  cephalad.  Less  frequently  is  it  independent  of  the  coronal,  as  in  PI.  I,  Fig.  2,  and 
the  left  side  of  Fig.  1 ;  most  rarely  is  it  wholly  isolated  as  a  simple  diagonal  fissure,  as  in 
Fig.  21  and  the  right  of  PI.  I,  Fig  1.  Nevertheless,  Krueg  and  the  senior  author  came 
independently  to  the  conclusion  that  this  is  the  primitive  condition  of  the  fissure  and  the 
one  to  be  represented  upon  a  diagram. 

§  1354.   Fissura  anterior,  F.  a.— Fig.  24  ;  PI.  I,  Fig.  1,  2 ;  PI.  Ill,  Fig.  5. 

The  disconnection  of  the  dorsal  end  of  this  fissure  from  that  of  the  postica,  so  that  the 
keystone  of  the  first  arch  is  absent,  constitutes  a  constant  distinction  between  all  the 
Felidse  and  the  feral  Canidse  and  most  domestic  dogs.  The  two  fissures  sometimes 
approach  quite  closely  and  even  overlap,  but  we  have  never  observed  a  junction.  On  the 
other  hand,  while  the  two  form  a  continuous  fissure  in  all  feral  Canidae  and  most  domesti- 
cated dogs,  in  the  latter  the  arch  is  sometimes  broken,  giving  this  region  of  the  brain  a 
feline  aspect  (Wilder,  1 1,  229,  and  Fig.  13,  16).  In  this  as  in  other  respects,  the  dog  dis- 
plays more  variability  than  the  cat. 

§  1355.  Fissura  cruciata,  F.  cr.— Fig.  117,  124,  125  ;  PI.  I,  Fig.  1,  2  ;  PI.  II,  Fig.  4; 
PI.  Ill,  Fig.  5 ;  PI.  IV,  Fig.  16-19. 

^  1356.  Constant  and  Peculiar  Characters. — Indents  the  dorso-mesal  margin  of  the 
hemisphere  near  its  cephalic  end,  so  as  to  appear  upon  both  the  dorsal  and  mesal  aspects. 
Length  of  the  dorsal  and  mesal  portions  approximately  equal.  Dorsal  portion  at  a  right 
angle  with  the  meson.  Line  formed  by  the  dorsal  portions  of  the  two  fissures  about  one 
half  the  length  of  the  line  representing  the  F.  inierliemispheralis,  with  which  it  forms  a 
Roman  cross.     Lateral  end  simple  and  independent. 

§  1357.  Variable  Characters.— Qo^n^^^.  end  of  mesal  part  of  fissure  usually  dorsad  of 
the  junction  of  the  cephalic  and  middle  thirds  of  the  callosum,  and  about  two  fifths  of  the 
distance  from  the  callosum  to  the  dorsal  margin  of  the  hemisphere,  thus  about  midway 
between  the  callosum  and  the  cephalic  end  of  the  F.  splenialis.  Rarely  are  these  two 
fissures  continuous. 

§  1358.  The  dorsal  part  of  this  fissure  is  a  marked  feature  of  the  dorsal  and  cephalic 
aspects  of  the  hemisphere,  on  account  of  its  straightness,  simplicity  and  independence,  and 


THE    CRUCIATE    FISSURE.  499 

its  relation  to  the  F.  interhemispheralis.  Its  symmetry  is  also  remarkable  ;  very  rarely  is 
tlie  mesal  end  on  one  side  farther  caudad  than  on  the  other. 

The  mesal  portion  is  less  uniform.  The  caudal  half  often  tends  slightly  dorsad  and 
the  end  is  sometimes  forked.  Rarely  does  the  caudal  end  join  the  F.  spleuialis.  Accord- 
ing to  Krueg  {'4,  620j,  the  union  was  observed  once  by  Guillot  (A,  Fig.  172) ;  Krueg  him- 
self has  sjen  it  only  twice. (;^,  630),  and  Pansch  (/,  21,  Fig.  27)  three  times  out  of  fourteen. 
Out  of  about  400  hemispheres  of  adult  cats  dissected  by  us  or  our  students  or  preserved 
in  the  Museum  of  Cornell  University  and  in  the  Museum  of  Comparative  Zoology,  it 
was  noticed  in  only  4. 

In  view  of  Broca's  idea  (jf)  that  the  cruciata  and  splenialis  are  morphologically  parts  of 
a  single  fissural  integer,  their  relations  should  be  carefully  examined ;  note  should  be 
taken  as  to  whether  a  j  unction  is  effected  by  means  of  branches  or  by  a  deflection  of  one 
or  bjtii  of  the  fissures  themselves  ;  whether  the  combined  fissure  is  shallower  at  the  place 
of  junction,  and  whether  the  junction  exists  upon  both  hemispheres. 

This  fissure  is  also  interesting  on  account  of  the  various  opinions  which  have  been 
expressed  as  to  its  human  homologue  (see  §  1370),  and  because  several  well-marked 
"  motor  centers  "  have  been  found  about  its  dorsal  portion  ;  apparently  none  have  been 
discovered  upon  the  mesal  surface  of  the  hemisphere. 

§  1359.  Formation. — As  intimated  by  the  senior  author  (11,  226),  and  more  distinctly 
shown  by  Pansch  (i,  Fig.  32)  and  Krueg  {2,  Taf.  XXXIV),  the  F.  cruciata  really  begins 
upon  the  mesal  aspect  of  the  hemisphere,  as  a  shallow  depression  which  gradually  ap- 
proaches the  margin,  indents  it,  and  finally  extends  laterad  for  a  distance  equal  to  or 
greater  than  its  mesal  part.  Upon  a  series  of  kitten's  brains,  from  a  week  before  birth 
to  a  week  after,  the  formation  of  this  fissure  is  beautifully  illustrated. 

§  1360.  The  Name. — Owen's  "frontal "  is  descriptively  significant,  but  it  imjJies  a  not 
yet  proven  homology  with  one  of  the  human  frontal  fissures,  and  is  antedated  by  Leuret's 
"  crucial."  As  to  the  technical  form,  there  seems  little  to  choose  between  crucialis  and 
cruciata.  Personally  we  prefer  the  former,  but  Krueg  has  employed  the  latter,  and  his 
name  is  here  adopted. 

§  1361.  Synonymy. — The  following  synonymy  is  chronological,  and  intended  to  include 
all  the  works  and  papers  in  which  the  cruciate  fissure  is  mentioned.  It  forms  part  of  an 
unpublished  paper  by  the  senior  author  which  is  mentioned  in  8,  49,  and  14,  524. 

Cuvier  (1805) ;  ""en  avant,  un  sillon  court  qui  la  traverse  en  croix  ;  "  Carnivora  ;  C, 
II,  157. 

Owen  (1833) ;  "  a  transverse  anfractuosity—the  transverse  anfractuosity — the  first  trans- 
verse fissure  ;  "  cat,  cheetah  ;  35,  133,  134  ;  PI.  XX,  "  1." 

Owen  (1835) ;  "  the  anterior  transverse  anfractuosity  ;  "  Cercoleptes  (kinkajou)  j  53, 
122. 

Leuret  (1839) ;  "sillon  crucial ;"  cat  and  the  Carnivora  generally  ;  Leuret  et  Gratio- 
let,  A.  I,  379,  etc.,  PI.  V,  Fig.  3,  opposite  "  a." 

Cuvier,  Dumeril,  etc.  (1845);  "sillon  crucial;"  Felidae  and  most  other  Carnivora; 
Cuvier,  B,  III,  93. 

Dareste  (1855);  ''sillon  crucial;"  cat  and  several  other  Carnivora;  13,  110,  PI.  II, 
Fig.  1,  2,  4,  8,  "/•" 

Owen  (1868) ;  "  the  frontal  fissure  ;  "  cat  and  the  "  Gyrencephala  "  generally  ;  A,  III, 
116-136,  Fig.  91,  etc.,  "  I4," 

Flower  (1869) ;  "  crucial  sulcus,  crucial  fissure  ;  "  Proteles  cristata  and  the  Carnivora 
generally  ;  2S,  479,  482,  Fig.  1,  2,  4,  "  c." 


500  ANATOMICAL    TECHNOLOGY. 

Flower  (1870)  ;  "crucial  sulcus  ;  "  Ailurus  fulgens ;  35,  755,  Fig.  1,  2,  8,  "  c." 

Lussana  e  Lemoigne  (1871);  '' scissura  crociata;"  cat  and  many  other  mammals* 
A,  I,  142,  Fig.  127,  191. 

Fritsch  und  Hitzig  (1870) ;  '' frontal  fissure  ;  "  dog  ;  1,  312. 

Gervais  (1870) ;  cephalic  part  of  "  sUlon  crucial ;  "  most  Carnivora  ;  146, 105. 

Huxley  (1870)  ;  "  crucial  sulcus— anterior  end  of  the  calloso-marginalis  ;  "  dog;  A,  420. 
.    Hitzig  (1873)  ;  '' frontal  fissure  ;  "  dog  ;  4,  434,  Fig.  1,  2,  3,  "  14." 

Wilder  (1873) ;  "  frontal  fissure  ;  "  cat  and  the  Carnivora  generally ;  1 1,  225,  Fig.  15 
17,  etc.,  -/•" 

Hitzig  (1874)  ;  ''sulcus  cruciatus— frontal  fissure— fissura  frontalis;  "  cat  and  dog  ; 
A,  13,  46,  96,  129,  Fig.  1,  7,  "  U  "  or  *'  s.  c." 

Garner  (1876) ;  "  transverse  or  crucial  sulcus  ;  "  1,  153. 
.    Ferrier  (1870) ;  "crucial  sulcus;  "  cat,  dog  ;  A,  145-154,  Fig.  32-35,  '* b." 

Meynert  (1877) ;  "  der  Leuret'schen  querfurche — der  nordere  aufsteigende  ast  der  rand- 
furche  ;"  wild-cat,  etc. ;  i,  12,  Fig.  17,  etc.,  "  cm.-caU.  m." 

Huguenin  (Duval  et  Keller),  (1878) ;  "sulcus  cruciatus;"  dog,  fox,  etc.  ;  A,  55,  56, 
Fig.  40,  41,  "  sc." 

Broca  (1878) ;  1 ;  (this  reference  has  been  mislaid,  and  the  paper  is  not  now  accessible 
to  us). 

Foster  and  Langley  (1878) ;  "  crucial  fissure  ;  "  dog  ;  A,  219. 

Krueg  (1878);  "sulcus  cruciatus;"  dog  aud  Carnivora  generally;  1,  335,  345,  Taf. 
XXI,  "  cr." 

Horsley  (1879) ;  "  fissura  cruciata  ;  "  Carnivora;  1,217. 
•    Clevenger  (1879) ;  "  carnivoral  crucial  sulcus  ;  "  Carnivora  ;   1,  7. 

Pansch  (1879);  "  das  vordere  ende  der  medlale  hauptfurche  ;  "  cat  and  Carnivora  gen- 
erally ;  1,  21,  etc..  Fig.  26,  32,  43,  etc.,  "  m.  hf" 

Krueg  (1880);  "fissura  cruciata;"  most  Carnivora,  2,  610,  Taf.  XXXIV,  XXXVII, 
*'  cr." 

Wilder  (iSSO) ;  "fissura  cruciaia  ;  "  8,  50,  Fig.  1,  2. 

Mivart  (1881) ;  "  crucud  sulcus;  "  B,  259  and  261,  Fig.  125  and  126,  "  c." 

Wilder  (1881);  ''fissura  cruciata;"  cat;  14,  534;  PI.  I,  Fig.  1,  2;  PI.  II,  Fig.  4; 
PI.  II,  Fig.  5 ;  PI.  IV,  Fig.  16-19,  "  F.  cr." 

§  1362.  Designation  of  the  Gyri. — The  Sigmoid  Gyrus. — This 
name  has  been  used,  especially  by  English  writers,  to  designate 
the  approximately  s-shaped  fold  which  curves  about  the  lateral  end 
of  the  cruciate  fissure  (PI.  I,  Fig.  1).  Its  surface  includes  several 
quite  constant  and  well-marked  ''  motor  areas  "  (Ferrier,  A,  Fig.  32 ; 
Dalton,  A,  Fig.  113,  114). 

§  1363.  T?ie  External  or  Arched  Gyri. — The  four  arched  gyri  which  are  so  regularly 
arranged  in  the  fox  and  wolf  were  enumerated  by  Leuret  (Leuret  et  Gratiolet,  A,  I,  374; 
Atlas,  9),  beginning  with  that  which  immediately  borders  the  Sylvian  fissure,  and  endiag 
with  that  which  forms  the  margin  of  the  hemisphere. 

Since  the  fissure  is  constant  and  the  margin  variable,  this  would  seem  to  be  a  natural 
arrangement,  and  it  has  been  adopted  by  Huguenin  and  some  others.  As  appears,  how- 
ever, from  the  accompanying  Table,  several  writers  have  modified  it  or  reversed  the  order 
altogether.  Such  transpositions  are  troublesome  enough  for  skilled  anatomists,  and  can 
hardly  fail  to  perplex  the  beginner. 


THE    FISSURAL    PATTERN, 


501 


Table  showing  Fouh  Methods  of  Enumerating  the  "  Arched  Gyri." 


Location. 


Next  the  mesal  border  of  tlie  hemisphere. . . . 

Between  the  F,  lateralis  and  the  supersyld 
ana  and  postsykiiana 

Between  the  F.  supersylciana  and  the  an-  } 
terior  and  postica f 

Between  the  F.  anterior  and  postica  and  the  [ 
F.  Sylviana ) 


Leuret 
(Leuret  et 
Gratiolet), 

A,  380. 


Fourth . . 
Third.. . . 

Second. . 

First  .. 


Ferrier,  A, 
145. 


First.... 
Second.. . 

Third.... 

Fourth . . 


Flower, ;?«, 
479. 


Third.... 
Second.. . 

1^  First... 


Mivart,  B, 
259. 


Superior. 
Middle. 

Inferior. 


§  1364.  The  Angular  Gyrus. — This  name  is  applied  to  a  fold  of  the  hemisphere  in 
man  and  monkeys.  By  a  few  writers  it  has  been  given  also  to  the  caudal  portion  of  what 
Leuret  called  the  third  arched  convolution.  As  indicated  below  (§  1369),  we  do  not  think 
the  homologies  of  the  fissures  or  folds  are  sufficiently  well  determined  to  warrant  the 
application  of  this  name  to  the  Carnivora. 

§  1365.  The  Fissural  Pattern. — The  fissures  of  the  cat,  dog  and  fox  can  be  homolo- 
gized  in  most  respects,  yet  they  diflfer  to  such  an  extent  as  to  be  readily  distinguishable. 
If  we  could  accurately  determine  the  arrangement  of  fissures  which  is  common  to  all 
domestic  cats  and  peculiar  to  them,  we  might  be  able  to  define  the  fissural  pattern  of  the 
species. 

In  view  of  Ihe  inadequacy  of  our  knowledge,  we  have  thought  best  to  confine  the  dis- 
cussion of  the  fissural  pattern  to  a  brief  statement  of  what  appear  to  be  the  constant  and 
the  inconstant  fissural  characters  of  Fells  domestica. 

§  1366.  Constant  Characters. — (1)  Presence  of  the  following  nineteen  fissures  :  anterior, 
ansata,  cxillosal's,  coronalis,  cruciata,  diagonalis,  fimbrim,  hypocarnpm,  lateralis,  marginalis, 
olfactoria,  postica,  postrhinalis,  postsyMana,  rhinalis,  SyUiana,  splenialis,  super orhitalis, 
super  sylviana. 

(2)  Fissura  Sylviana  rather  short,  forming  not  more  than  one  third  nor  less  than  one 
eighth  of  an  imaginary  line  coinciding  therewith  and  extending  from  its  ventral  end  to 
the  dorsal  margin  of  the  hemisphere. 

(3)  Nine  fissures  are  so  placed  with  reference  to  the  Sylvian  as  to  form  three  irregular 
arches  dorsad  of  the  Sylvian,  corresponding  with  the  more  regular  arched  fissures  of  the 
fox  and  wolf ;  the  first  consists  of  the  postica  and  the  anterior,  the  diagonalis  often  being 
continuous  with  tlie  latter  ;  the  second,  of  the  postsylviana  and  supersylviana  ;  the  third, 
of  the  lateralis,  with  the  medilnteralis  when  present,  the  ansata  and  coronalis. 

(4)  Absence  of  a  fissure  {F.  cctolatcralis  of  Canidae)  between  the  caudal  portions  of  the 
lateralis  and  the  supersyhian. 

(5)  Disconnection  of  the  dorsal  ends  of  the  anterior  n^ndi  postica, 

(6)  Independence  of  the  F.  olfactoria. 

(7)  Independence  of  the  dorsal  ends  of  the  anterior,  postica,  superorUtalis  and  Sylviana  ; 
of  the  ventral  ends  of  the  hypocampcB,  coronalis  and  medilateralis  ;  of  the  caudal  ends  of 
the  splenialis  and  postradicalis  (when  present) ;  of  the  lateral  end  of  the  cruciata  ;  of  the 
mesal  end  of  the  ansata. 


502  ANATOMICAL     TECHNOLOGY. 

(8)  Continuity  of  the  rhinalis  with  the  postrhinalis  ;  of  the  Sylvian  with  the  point  of 
their  junction  ;  of  the  superorbital  with  the  rhinalis  ;  of  the  callosal  with  the  hypocampal, 
and  with  the  prcBradiccdis  when  present. 

§  1367.  Variable  Characters. — (1)  More  or  less  frequent  presence  of  the  following  ten 
inconstant  fissures  :  confinis,  falcialis,  intermedia,  lunata,  medilateralis,  postcruciata,  post- 
marginalis,  postradicalis,  prceradicalis,  svhfalcialis. 

(2)  Frequent  union  of  the  ansata  with  the  coronalis  and  lateralis;  of  the  lateralis  with 
the  ansata  und.  medilateralis ;  of  the  diagonalis  with  the  anterior;  of  the  supersykian 
and  postica  ;  of  the  marginalis  with  the  postmarginalis. 

(3)  Occasional  unions  of  the  medilateralis  End  confinis ;  of  the  cruciata  smd  the  sple- 
nialis. 

(4)  Very  rare  unions  of  the  postica  and  the  rhinalis  ;  of  the  anterior  with  the  super- 
sylvian. 

§  1368.  Homology  of  the  Human  and  Feline  Fissures. — The  determination  of  the 
identity  of  the  human  fissures  with  those  of  the  other  Mammalia  has  long  been  desired  from 
the  standpoint  of  Comparative  Morpliology  and  Systematic  Zoology.  Referring  in  1868  to- 
his  Lectures  on  the  Brain  in  1842,  Owen  says  (A,  III,  116):  'The  main  object  which  I 
had  in  view  was  the  determination  of  the  homologous  and  superadded  convolutions  in  the 
more  complex  prosencephalon  of  man." 

Since  the  discovery  in  1870  by  Fritsch  and  Hitzig  (1)  of  the  electrical  excitability  of 
certain  areas  of  the  cerebral  cortex  in  the  dog  and  cat,  and  the  confirmation  of  this  upon 
monkeys  by  Ferrier  (A,  138),  there  have  been  likewise  physiological  and  psychological 
reasons  for  the  determination  of  these  fissural  homologies,  and  at  this  time  probably  few 
biological  events  would  be  more  generally  welcomed  than  the  presentation  of  incontro- 
vertible evidence  as  to  the  human  homologue  of  the  carnivoral  Fissura  cruciata,  or  the 
representative  of  the  human  centralis  {Ftssure  of  Rolando)  in  the  cat  and  dog. 

§  1369.  The  following  are  sufficient  general  examples  of  the  difiiculties  which  sur- 
round the  subject  and  of  the  differences  of  opinion  among  high  authorities : — 

Gratiolet  wrote  (A,  10) : — 

"  We  need  only  compare  the  brain  of  an  ape  with  that  of  a  carnivore  or  a  ruminant  to 
see  that  the  convolutions  present  very  dissimilar  general  arrangements  in  the  several 
orders  of  Mammalia.  These  differences  are  so  great  that  it  would  be  imprudent  to  estab- 
lish corresponding  subdivisions  and  to  investigate  their  homologies.  In  fact,  this  ques- 
tion has  as  yet  no  basis  of  certainty,  and  we  think  that  for  the  present  it  should  not  be 
undertaken." 

Owen  says  (25)  that  the  same  names  apply  to  the  fissures  of  the  Aye-aye  and  the  cat, 
while  the  very  next  paper  in  the  volume  of  the  Zoological  Transactions  contains  the 
admission  of  Flower  (6)  that,  as  between  the  Lemurs  and  the  Carnivora,  the  "  nomencla- 
ture utterly  fails  " 

§  1370.  Special  examples  of  the  diversity  of  opinion  are  furnished  by  the  two  fissures 
already  named,  the  cruciata  or  "  frontal  "  of  the  cat  and  dog  and  the  centralis  of  man. 

The  centralis  is  homologized  with  the  super orbitnlis  bv  Duval  and  Keller  (A,  57,  note)^ 
and  apparently  by  Broca  ;  Hitzig  (A,  136,  137,  Fig.  10,  11)  makes  it  equivalent  to  the 
ansata  together  with  a  part  of  the  supersylciana,  a  view  which  derives  some  support  from 
the  occasional  interruption  of  the  human  centralis  ;  it  is  the  homologue  of  the  coronalis 
in  the  opinion  of  Owen  (A,  III,  130),  Meynert  {1),  and  Pansch  (i,  47).  In  an  earlier 
paper,  however,  Pansch  regarded  the  centralis  as  homologous  with  the  cruciata,  and 
this  is  the  opinion  of  Ferrier  and  Clevenger. 

The  cruciate  fissure  of  the  Carnivora  is  said  by  Ferrier  (A,  199)  to  be  experimentally 
the  equivalent  of  the  centralis,  and  Clevenger  {2, 14)  states  that  the  two  fissures  are  "  his- 


HOMOLOGY    OF   HUMAN   AND    FELINE    FISSURES.  503 

tologically  as  well  as  physiologically  analogous,"  although  in  a  previous  paper  (i,  24)  he 
had  declared  that  "  anatomically,  the  crucial  and  Rolandic  are  not  capable  of  comparison ;" 
Lussaua  and  Lemoigne  (A,  Fig.  75)  make  the  cruciata  equivalent  to  the  calloso-marginalis 
of  man,  while  Duval  and  Keller  (Huguenin,  A,  57,  note)  consider  it  as  *'  I'analogue  du  sil- 
lon  perpendiculaire  externe  ou  sillon  occipital  de  I'liomme;"  Broca  (1,  407)  is  sure  that 
the  cruciata  is  not  the  representative  of  the  centralis,  and  its  existence  with  the  Primates 
is  denied  altogether  by  Hitzig  (A,  430)  and  Meynert  (J,  659,  note). 

After  having  followed  up  all  the  clues  at  our  disposal,  and  spent  upon  this  single  mat- 
ter more  time  than  we  supposed  would  be  required  for  the  elucidation  of  the  gross  anat- 
omy of  the  entire  brain,  we  are  forced  to  admit  our  inability  to  satisfy  ourselves  completely 
with  respect  to  the  homology  of  the  carnivoral  fissures  with  those  of  man,  excepting  of 
course  the  hypocampal  and  callosal,  which  have  never  presented  any  difficulty  on  account 
of  their  relation  to  structural  features  ;  as  to  the  existence  of  a  "  lambdoidal"  or  "occipi- 
to-parietal  "  fissure  in  the  cat,  see  §  1834  (20). 

So  long,  indeed,  as  any  doubt  exists  with  regard  to  the  correspondence  of  the  fissures 
of  the  cat,  seal  and  raccoon,  and  of  man,  Macacus  and  Lemur,  it  is  hardly  to  be  expected 
that  the  homology  between  the  members  of  the  two  groups  should  be  altogether  clear, 

§  1371.   The  following  lines  of  inquiry  seem  likely  to  be  most  productive  of  results  : — 

(1)  Numerous  and  careful  preparations  and  drawings  should  be  made  of  the  brains  of 
all  Carnivora  and  monkeys,  especially  of  the  young.  The  same  should  be  done  for  pecu- 
liar foetal  and  adult  human  brains. 

(2)  Between  the  ordinary  Carnivora  and  the  monkeys  are  two  groups  whose  brains 
should  be  studied  with  especial  care  :  the  seals  have  a  rudimentary  postcornu  and  occipital 
lobe,  and  these  parts  are  said  to  be  well  developed  in  the  Lemurs,  which  have  aflBnities 
with  both  the  Carnivora  and  the  Primates. 

Respecting  the  brains  of  the  lower  Vertebrates,  see  Appendix,  §  1455. 


CHAPTER    XI. 

THE  CRANIAL  NERVES  AND  ORGANS  OP   SENSE. 

GENERAL  CONSIDERATIONS — CLASSIFICATION  OF  THE  CRANIAL  NERVES — TABLE  OF  TfiB 
CRANIAL  NERVES— SKIN — TONGUE— NOSE— EYE  AND  ITS   APPENDAGES —EAR. 

§  1372.  The  Cranial  Nerves — General  Considerations. — As 
briefly  described  in  §§  996,  1007,  and  shown  in  Fig.  104,  109,  most 
of  the  nerves  of  the  trunk  and  limbs  are  connected  with  the  myelon 
by  two  sets  of  roots  which  respectively  emerge  from  its  dorso-lateral 
and  ventro-lateral  aspects  opposite  the  dorsal  and  ventral  cornua  of 
the  cinerea.  The  dorsal  roots  bear  each  a  ganglion,  and  they  are 
sensory^  while  the  ventral  have  no  ganglion  (Fig.  109)  and  are 
motor. 

Each  dorsal  root  is  joined  by  a  corresponding  ventral  root,  and 
the  trunk  so  formed  has  both  motor  and  sensory  functions. 

The  roots  and  trunks  vary  in  size  and  in  the  number  c^f  their 
rootlets  and  branches  ;  they  vary  also  to  some  extent  in  their  rela- 
tions with  the  sympathic  nerves  and  the  viscera.  Upon  the  whole, 
however,  they  form  a  series  all  the  members  of  which  are  readily 
and  quite  closely  comparable. 

§  1373.  But  the  cranial  nerves  (which  either  arise  from  the 
encephalon  or  eventually  escape  through  cranial  foramina)  present 
no  such  simplicity  in  any  animals,  and  in  man  and  most  mammals 
their  irregularities  in  origin  and  distribution  are  so  great  that  the 
older  anatomists  seem  not  to  have  attempted  any  comparison  with 
the  myelonal  type.  Their  functions  likewise  were  imperfectly 
known,  and  they  were  therefore  numbered  in  order,  beginning  at 
the  cephalic  end  of  the  brain,  and  their  names  referred  mainly  to 
their  anatomical  connections. 


THE    CRANIAL    NERVES^ 


505 


§  1374    TABLE  OF  THE  SFNONYMS  OF  THE  CRANIAL  NERVES. 


SOmmering. 


I 

n 

m 

IV  

V 

VI 

VII 

VIII 

IX 

X 

XI 

XII 


Technical  names  herein  adopted. 


Olfactorii , 

Opticus 

Oculomotorius. . . . 

Trochlearis , 

Trigeminus 

Abducens , 

Facialis 

Auditorius 

Glossopharyngeus. 

Vagus 

Accessorius 

Hypoglossus 


Synonyms. 


Rhinencephalici. 


Motor  oculi  communis. 

Patheticus. 

Trifacialis 


Portio  dura 

Portio  mollis,  Acusticus. 


Par  vagum,  pneumogastricus . . 
Accessorius  spinalis 


WUlis. 


I. 

11. 

IIL 

IV, 

V. 

VL 

VII. 


VIII. 
IX 


§  1375.  Designation  of  the  Cranial  Nerves  by  Numbers.— 

Among  the  older  anatomists  (as  may  be  seen  from  Yicq  d' Azyr,  A, 
'*  Explication,"  48-50),  the  cranial  nerves  were  variously  enume- 
rated. At  the  present  day  only  two  methods  are  commonly  em- 
ployed, those  of  Sommering  and  Willis.  As  indicated  upon  the 
accompanying  Table,  the  difference  between  these  two  concerns  only 
half  of  the  twelve.  The  7th  and  8th  of  Sommering  constitute  the 
Portio  dura  and  the  Portio  mollis  of  Willis's  7th;  the  9th,  10th 
and  11th  of  Sommering  are  included  in  the  8th  of  Willis,  and  the 
12th  of  the  former  represents  the  9th  of  the  latter. 

Fortunately,  the  nerve  most  often  concerned  in  medicine  and 
surgery  is  the  5th,  the  seat  of  toothache  and  most  other  forms  of 
facial  neuralgia.  Upon  the  whole,  it  would  be  better  to  abandon 
the  use  of  the  numbers  altogether  and  employ  only  the  technical 
names  here  given,  with,  perhaps,  the  substitution  of  the  shorter 
word  acusticus  for  auditorius,  Nevertheless,  in  the  Descriptions 
(§§  1380-1391)  and  in  the  Table  (p.  520),  the  numerical  order  is  fol- 
lowed for  convenience  of  reference. 

§  1376.  Arrangement  of  the  Cranial  Nerves. — These  nerves 
have  been  variously  classified  in  accordance  with  physiological  or 
morphological  facts  and  theories. 

The  following  Table  exhibits  the  provisional  physiological 
arrangement  which  was  outlined  by  Wyman  (34,  40)  and  has  been 
elaborated  by  Dalton  (A,  447). 


5oa 


ANA TOMICAL    TECHNOL OGY, 


%  1377.    PROVISIONAL  PHYSIOLOGICAL  ARRANGEMENT  OF   THE   CRANIAL 
NERVES.     (Slightly  altered  from  Dalton,  A,  447.) 

A.    Nerves  op  Special  Sense,  lacking  General  Sensibility. 
i.    Olfactorii.  2.     Opticus.  3.     Auditorius. 

B.    Motor  and  Sensory  Nerves  comparable  with  Myelonal  Nerves. 


Sensory  Nerves  (with  Gan- 
glia.) =  Dorsal  Roots  of 
Myelonal  Nerves. 


Trigeminus  (Radix  sensoria). 
Gng.  Gasseri. 

Glossopharyngeus. 

Gng.  petrosum. 
Vagus. 

Gng.  jugulare. 


Motor  Nerves  =  Ventral 
Roots  of  Myelonal 
Nerves. 


r  Oculomotorius. 

Troclilearis. 
\  Abducens. 

I  Radix  motoria  (trigemini). 
l^  Facialis. 

Hypoglossus. 

Accessorius. 


General  Distribution. 


Skin,  mucosa  and  muscles  of 
face. 


Tongue  and  pharynx. 

Passages  of  respiration  and 
deglutition,  etc. 


§  1378.  Dalton  recognizes  two  great  divisions,  the  nerves  of  spe- 
cial sense  and  ordinary  motor  and  sensory  nerves.  Since  some  of 
the  latter  also  possess  special  sensibility,  the  former  may  perhaps 
"be  characterized  as  nerves  of  special  sense  which  lack  general 
sensibility  and  have  no  ganglia. 

The  other  and  larger  division  includes  nerves  which  are  anatom- 
ically and  physiologically  distinguishable  into  two  groups,  cor- 
responding respectively  to  the  dorsal  and  ventral  roots  of 
myelonal  nerves.  Three  of  these  bear  each  a  ganglion,  like  that 
upon  the  dorsal  root  of  a  myelonal  nerve,  and  are,  at  their  origin, 
exclusively  sensitive.  The  others  apparently  lack  ganglia  and  are 
functionally  motor. 

But  while  the  foregoing  Arrangement  is  at  least  convenient  and 
serves  to  impress  upon  the  mind  of  the  student  the  probability 
that,  as  the  "  medulla  "  is  a  modification  of  the  myelon,  so  some  at 
least  of  the  cranial  nerves  are  modifications  of  the  myelonal  type,  yet 
sight  should  not  be  lost  of  certain  ascertained  or  probable  facts  of 
Embryology  and  Comparative  Anatomy  which  are  not  in  full  accord 
therewith. 

These  facts  and  considerations  are  admitted  by  Wyman  and  Dal- 
ton, and  others  are  presented  in  the  compendiums  of  Huxley,  A,  6G-71, 


THE    CRANIAL    NERVES.  507 

Gegenbaur  (Lankester),  A,  515-522,  and  Balfour,  A,  II,  374-383, 
and  in  the  papers  there  cited.     See  also  A.  M.  Marshall  (4). 

§  1379.  In  the  following  brief  descriptions  of  the  cranial  nerves, 
only  the  ectal  or  superficial  or  apparent  origins  are  given.  Their 
ental  (real  or  deep)  origins  in  man  are  presented  briefly  in  Gray  and 
Quain,  and  more  fully  in  Meynert  (Strieker,  A,  727-751),  and  in 
special  papers. 

§  1380.  (I)  Nervi  olfactorii,  N.  ol,  the  olfactory  nerves.— Fig.  110  ;  §  1160.  Gray, 
A,  620 ;  Quain,  A,  I,  526. 

The  true  olfactory  nerves  of  the  cat  and  man  are  soft  fibrous  fasciculi  which  pass  from 
the  surface  of  the  2^ero  through  the  olfactory  foramina  of  the  cribriform  plate  of  the  eth- 
moid bone  (Fig.  60,  88),  to  be  distributed  to  the  nasal  mucosa  (§  1398,  membrana  Sclinei- 
deriana). 

On  account  of  the  small  size  of  the  Lobus  olfactorius  in  man,  it  was  formerly  regarded 
as  a  nerve,  and  is  still  often  so  called.  As  shown  both  by  development  and  by  comparison 
with  the  lower  animals,  it  is  really  a  protrusion  or  lobe  of  the  brain. 

§  1381.  (II)  Nervus  opticus,  N.  op.,  the  optic  nerve.— Fig.  110,  116,  117  ;  PI.  I, 
Fig.  3  ;  PI.  II,  Fig.  3,  4  ;  PI.  Ill,  Fig.  5  ;  PI.  IV,  Fig.  16, 18, 19.  Gray,  A,  628  ;  Quain, 
A,  I,  527. 

Each  optic  nerve  is  a  cylindrical  white  cord  springing  from  the  side  of  the  chiasma 
(§  1202)  and  passing  through  the  optic  foramen  (Fig.  57,  Fm.  op.)  to  the  eyeball. 

The  optic  nerves  are  formed  by  protrusions  of  the  primitive  diencephalon,  and  are 
hence,  like  the  olfactory  lobes,  regarded  by  Gegenbaur  (Lankester),  A,  515,  as  prolonga- 
tions of  the  brain. 

The  cavity  is  obliterated,  and  in  man  the  fibers  constituting  the  nerve  have  been 
traced  not  only  to  the  thalami  and  geniculata,  but  also  to  the  optici.  We  have  not  traced 
them  carefully  in  the  cat. 

§  1383.  (Ill)  Nervus  oculomotorius,  W.  ocm.,  the  oculomotor  nerve. — Fig.  116 ;  PI. 
11,  Fig.  3.     Gray,  A,  640  ;  Quain,  A,  I.  528. 

The  trunk  of  this  nerve  is  cylindrical  and  about  1  mm.  in  diameter.  It  arises,  slightly 
flattened,  from  the  Area  intercruralis,  about  3  mm.  from  the  meson  and  just  caudad  of  the 
cimbia  (§  1203),  is  closely  associated  with  the  ophthalmic  division  of  the  N.  trigeminus, 
and  emerges  therewith  by  the  Fm.  lacerum  anterius  to  be  distributed  to  all  the  muscles 
of  the  eyeball  which  are  not  supplied  by  the  trochlearis  and  abducens  ;  it  goes  also  to  the 
levator  palpebrse  dorsal  is  muscle. 

§  1383.  (IV)  Nervus  trochlearis,  N.  tr.  the  trochlear  or  patheticus  nerve.— Fig.  116  ; 
PI.  I,  Fig.  3  ;  PI.  II,  Fig.  3  ;  PI.  Ill,  Fig.  9.     Gray,  A,  641  ;  Quain,  A,  I,  519. 

This,  the  smallest  of  the  cranial  nerves,  arises  from  the  valvula  by  three  fasciculi. 
The  trunk  is  involved  in  the  pia  and  easily  torn  away  therewith. 

It  passes  laterad  and  then  ventro-cephalad  between  the  cerebellum  and  the  hemi- 
sphere, associates  itself  with  the  ophthalmic  division  of  the  trigeminus,  and  emerges 
therewith  by  the  Fm.  lacerum  anterius  to  supply  the  M.  trochlearis  ("  obliquus  superior  "). 
According  to  the  Thesis  of  C.  E.  Manierre,  this  nerve  enters  the  ocular  aspect  of  the  mus- 
cle in  the  cat,  while  in  man  it  enters  the  orbital  or  ectal  aspect. 

§  1384.  (V)  Nervus  trigeminus,  i\r.  trg.,  the  trigeminal  or  trifacial  nerve,— Pig.  116  ; 
PI.  II,  Fig.  3.    Gray,  A,  647  ;  Quain,  A,  I,  533. 

This  is  the  largest  of  the  cranial  nerves  and  peculiar  in  several  respects.     Although 


508  ANA  TOMICAL    TECHNOL  OGY. 

commonly  described  as  a  single  nerve,  it  really  consists  of  two,  the  larger  being  sensory 
(Radix  sensoria)  and  tlie  smaller  motor  (Radix  motoria).  It  tlms  conforms  to  a  myelonal 
nerve,  excepting  that  the  ectal  origins  of  the  two  roots  are  closely  associated. 

The  sensory  root  is  a  large,  slightly  flattened  band  which  lies  across  the  pons  just 
where  it  is  contracted  to  form  the  medipedunculus.  When  lifted  from  the  pons,  it  is 
found  to  have  its  ectal  origin  either  just  caudad  of  it  or  from  its  surface  close  to  the  caudal 
border. 

In  the  senior  author's  paper  {14,  548),  the  nerve  is  simply  said  to  arise  caudad  of  the 
jwns.  This  statement  was  questioned  in  the  Am.  Jour,  of  Neurology,  etc.  (I,  103) ;  a 
reexamination  of  several  preparations  shows  the  existence  of  the  variation  above  indi- 
cated, and  a  qualification  has  been  published  (Wilder,  24). 

In  man  the  ectal  origin  is  through  the  pons  nearer  the  cephalic  than  the  caudal  mar- 
gin. In  part,  at  least,  the  difference  is  due  to  the  greater  caudal  extension  of  the  human 
pons  (§  1161). 

At  the  cephalic  border  of  the  pons  the  root  presents  a  large  flattened  ganglion  (Qng. 
Gasseri)  and  then  separates  into  three  divisions — the  ophthalmic,  maxillary  and  mandibu- 
lar. Of  these,  the  first  is  the  most  mesal  in  position  and  the  smallest,  but  with  it  are  asso- 
ciated the  oculomotorius,  trochlearis  and  abducens,  all  emerging  together  from  the  Fm. 
lacerum  anterius. 

The  maxillary  division  is  intermediate  and  escapes  by  the  Fm.  rotund  um.  The  man- 
dibular division  is  lateral,  is  joined  by  the  Radix  motoria  and  emerges  by  the  Fm.  ovale. 

The  distribution  is  stated  upon  the  Table  (§  13D2),  and  corresponds  in  the  main  with 
the  three  regions  of  the  face ;  some  filaments  also  supply  the  dura. 

The  motor  root  (Radix  motoria)  is  much  smaller  than  the  sensory  and  not  easily  recog- 
nized. Upon  a  fresh  brain  it  may  be  seen  as  a  narrow,  light  band  crossing  the  S3nsory 
root  and  the  ganglion  from  the  mesal  side  of  the  former,  to  attach  itself  to  the  mandibular  ' 
division.  Upon  an  alcoholic  brain,  a  dull  tracer  may  be  used  to  isolate  it  in  the  middle  of 
its  course  and  follow  it  to  its  origin  mesad  and  slightly  cephalad  of  that  of  the  sensory 
root.  We  have  not  ascertained  whether,  as  in  man,  it  is  separated  therefrom  by  a  few 
fibers  of  the  pons  or  of  the  trapezium. 

In  man  the  motor  root  is  distributed  to  the  muscles  concerned  in  mastication  (Dalton, 
A,  464).  I 

§  1385.  Nervus  abducens,  N.  abd.,  the  abducens  nerve.— Fig.  116  ;  PI.  II,  Fig.  3. 
Gray,  A,  641 ;  Quain,  A,  I,  519. 

A  ribbon-shaped  nerve,  arising  by  three  or  four  funiculi  from  the  trapezium  just  laterad 
of  the  pyramis.  The  attachment  is  very  feeble  and  the  nerve  is  apt  to  be  torn  off  with 
the  pia.  It  associates  itself  with  the  ophthalmic  division  of  the  trigeminus  and  emerges 
therewith  by  the  Fm.  lacerum  anterius  to  be  distributed  to  the  MM.  choanoidei  and  the 
rectus  lateralis  ("  externus  "). 

§  1386.  (VIT)  Nervus  facialis,  N.  /.,  the  facial  nerve  or  "  portio  dura."— Fig.  116  : 
PI.  II,  Fig.  3.     Gray,  A,  642  ;  Quain,  A,  I,  548. 

In  some  respects  this  is  the  motor  counterpart  of  the  trigeminus,  being  distributed  to 
most  of  the  muscles  of  the  face  and  head,  excepting  the  muscles  of  mastication.  It  is 
small  as  compared  with  the  trigeminus,  just  caudad  of  which  it  arises  from  the  latero- 
cephalic  angle  of  the  trapezium.  It  traverses  the  eutal  auditory  foramen,  the  Aquseductus 
Fallopii  and  the  stylo-mastoid  foramen  (§  506). 

§  1387.  (VIII)  Nervus  auditorius,  -Z\^.  an.,  the  auditory  or  acoustic  nerve  or  portio 
mollis.— Fig.  110,  116  ;  PI.  II,  Fig.  3.     Gray.  A,  639  ;  Quain,  A,  I.  548. 

This  is  commonly  grouped  with  the  olfactory  and  optic  nerves  as  a  nerve  of  special 


THE    CRANIAL    NERVES.  509 

sense ;  but  according  to  Gegenbaur  (Lankester),  A,  515,  it  is  developed  like  an  ordinary- 
cranial  nerve. 

It  springs  from  the  cephalic  part  of  the  Eminentia  auditoria,  traverses  the  ental  audi- 
tory meatus,  and  is  distributed  to  the  sensory  organs  of  the  labyrinth  or  "  internal  "  ear. 

§  1388.  (IX)  Nervus  glossopharyngeus,  iV^.  ^^^A. ,  the  glossopharyngeal  nerve.— Fig. 
116  ;  PI.  II,  Fig.  3.     Gray,  A,  C58 ;  Quain,  A,  I,  554  ;  Stovvell,  1. 

The  origins  of  this  nerve  and  of  the  vagus  and  accessorius  are  associated  so  as  to  form 
a  series  extending  caudad  from  the  Eminentia  auditoria  for  a  considerable  distance  along 
the  lateral  aspect  of  the  cervical  myelon.  We  have  not  examined  these  origins  in  detail, 
and  the  reader  is  referred  to  the  figures  and  descriptions  of  Stowell.  As  has  been  stated 
elsewhere,  the  points  of  origin  cannot  be  defined  accurately  until  the  ectal  features  of  the 
"  medulla  "  are  more  satisfactorily  understood. 

The  nerve  has  a  ganglion  (Gng.  petrosum),  emerges  through  the  Fm.  jugulare,  and  is 
distributed,  in  man,  to  the  base  of  the  tongue,  the  soft  palate  and  the  pharynx. 

§  1389.  (X)  Nervus  vagus,  N.  v.,  the  vagus  or  pneumogastric  nerve. — Fig.  116  ;  PI. 
II,  Fig.  3.     Gray,  A,  660 ;  Quain,  A,  I.  556  ;  Stowell,  1. 

This  nerve,  remarkable  alike  for  its  distribution,  its  accessions  from  other  (motor) 
sources,  and  its  numerous  and  peculiar  functions,  arises  just  caudad  of  the  glossopha- 
ryngeus  by  several  funiculi,  which,  according  to  Stowell,  form  two  series,  dorsal  and 
ventral.  As  stated  under  the  glossopharyngeal,  we  have  not  fully  examined  the  origin, 
and  the  student  is  referred  to  the  figures  and  descriptions  of  Stowell. 

The  nerve  presents  a  ganglion  (Gng.  jugulare,  ganglion  of  the  root),  in  the  proximal 
end  of  the  foramen  of  exit,  and  about  15  mm.  peripherad  of  the  foramen  another,  the  Gug. 
inferius  or  the  ganglion  of  the  trunk  (Fig.  107  ;  Stowell,  J). 

Relations  of  the  Ganglia. — The  Gng.  jugularis  is  connected  by  anastomotic  filaments 
with  the  N.  facialis  (VII),  glossopharyngeus  (IX),  accessorius  (XI)  and  sympathicus. 
The  ganglion  of  the  root  is  connected  with  the  N.  glossopharyngeus  (IX),  accessorius 
(XI),  hypoglossus  (XII),  and  sympathicus ;  (Stowell,  1). 

Besides  the  connections  just  named,  the  vagus  furnishes  the  following  branches  :  NN. 
pharyngeus,  laryngeus  superior,  laryngeus  recurrens,  rami  cardiac!,  rami  pulmonares, 
gastricus  dorsalis  and  gastricus  ventral  is  (Fig.  103,  107 ;  §§  1040,  1041).  It  also  gives 
many  anastomotic  filaments  to  the  sympathicus  (§  1041  ;  Stowell,  1). 

%  1390.  (XI)  Nervus  accessorius,  N.  ac,  the  accessory  or  "  spinal  accessory  "  nerve. — 
Fig.  116  ;  PI.  II,  Fig.  3.     Gray,  A,  686  ;  Quain,  A,  I,  564;  Stowell,  1. 

This  nerve  has  a  peculiar  and  extensive  origin  by  funiculi  scattered  along  the  lateral 
aspect  of  the  metencephalon  and  cervical  myelon,  from  just  caudad  of  the  origin  of  the 
vagus  to  a  point  opposite  the  6tli  or  7th  cervical  nerve. 

The  trunk  enters  the  cranium  by  the  Fm.  magnum,  and  then  associates  itself  with  the 
vagus  and  glossopharyngeus  to  emerge  through  the  Fm.  jugulare.  In  man  it  is  distrib- 
uted to  the  trapezius  and  sterno-mastoid  muscles,  and  also,  by  the  fibers  which  join  the 
vagus,  to  the  heart. 

§  1391.  (XII)  Nervus  hypoglossus,  N.  hpg.,  the  hypoglossal  nerve. — Fig.  116  ;  PI.  II, 
Fig.  3.     Gray,  A,  646  ;  Quain,  A,  I,  565. 

Arises  by  several  (10-15)  funiculi  from  the  ventral  aspect  of  the  metencephalon  just 
laterad  of  the  caudal  half  of  the  Area  elliptica  (oliva  ?),  (The  difficulty  in  the  homology 
of  this  area  is  referred  to  in  §§  1161,  1188.) 

The  funiculi  are  very  slightly  attached  and  apt  to  be  torn  off  with  the  pia.  The  trunk 
escapes  through  the  Fm.  condylare,  and  is  distributed,  in  man,  chiefly  to  the  muscles  of 
the  tongue. 

This  nerve  has  much  the  aspect  of  the  ventral  root  of  a  myelonal  nerve. 


510 


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THE    ORGANS    OF   SENSE,  511 

§  1393o  The  demonstration  of  the  cranial  nerves  requires 
much  care  and  skill  on  account  of  the  great  number  crowded  into 
small  space,  and  also  because  they  pass  through  various  bony 
canals  d,nd  foramina  or  are  concealed  by  bony  processes.  The 
beginner  can  hardly  hope  to  demonstrate  all  satisfactorily  on  one 
specimen.  It  is  especially  necessary  to  employ  a  young  lean  ani- 
mal, in  order  that  fat  may  not  obscure  the  nerves  and  that  the  con- 
nective tissue  may  not  be  so  tough  as  to  render  the  tracing  of  fine 
nerves  impossible.  The  general  directions  for  dissecting  nerves 
given  in  §§  1008,  1037,  should  be  faithfully  followed.  Some  of  the 
nerves  may  be  traced  on  one  side  and  some  on  the  other.  When- 
ever a  saw  is  employed,  it  is  best  to  protect  underlying  parts  if 
possible  by  a  cloth.  In  case  a  vessel  or  nerve  is  inadvertently  sev- 
ered, the  two  ends  may  be  slightly  lapped  and  tied  with  a  thread. 
The  nippers  employed  should  be  sharp  and  narrow  pointed  (§  146). 
In  using  the  nippers,  remove  very  small  pieces,  and  use  the  tracer 
often  to  make  sure  that  all  branches  are  pushed  aside.  Have  at 
hand  for  constant  reference  a  prepared  skull,  the  figures  of  the  skull 
(Fig.  56-62),  and  the  Tables  of  foramina  (§  562)  and  nerves  (§  1392). 

THE  ORGANS  OP  SEISTSE. 

§  1394.  The  organs  of  sense  are  the  specialized  parts  of  animals- 
which,  being  acted  upon  by  objects  in  the  external  world,  are  capa- 
ble of  transmitting  the  impressions  so  received  to  the  central  ner- 
vous system  by  means  of  nervous  connections.    Huxley,  5. 

The  organs  are  fi^YQ^  corresponding  to  the  five  senses. 

(A)  Cutis  and  mucosa. — The  skin,  and  mucous  membranes  near 
the  exterior  (Dalton,  A,  510).  These  are  the  organs  of  Touch  (tac- 
tion, tactile  sensibility). 

(B)  Lingua  (tongue).  Soft  Palate  and  Fauces. — These  are  the 
organs  of  Taste  (gustation,  gustatory  sensibility). 

(C)  Nasus,  nose. — Its  mucous  membrane,  especially  that  of  the 
maxillo-turbinals,  forms  the  organ  of  Smell  (olfaction,  olfactory 
sensibility). 

(D)  Oculus,  eye. — The  organ  of  Vision  (sight  or  visual  sensi- 
bility). 

(E)  Auris,  ear. — The  organ  of  Hearing  (audition  or  auditory 
sensibility). 

(F)  General  Sensibility.— In  addition  to  the  special  sensibilities 


512  ANATOJIICAL    TECHNOLOGY. 

just  named,  requiring  a  special  apparatus,  there  is  the  so  called 
general  sensibility  of  the  body.  This  is  manifested  whenever  an 
ordinary  sensory  nerve  is  stimulated  in  any  part  of  its  course  ; 
when  slight,  it  is  called  feeling  ;  when  more  intense,  pain, 

CUTIS— THE  SKIN. 

References. — Gray,  A,  83  ;  Quain,  A,  II,  211  ;  Dalton,  A,  510 ;  Foster  and  Langley, 
A,  165  ;  Foster,  A,  589;  Leyh,  A,  350;  Strieker,  A,  792  ;  Chauveau,  A,  841  ;  Chauveau 
(Fleming),  A,  792  ;  Owen,  A,  III,  186,  610  ;  Gurlt,  A,  815  ;  Milne-Edwards,  A,  XI,  411 ; 
Bernstein,  A,  10  ;  Flint,  A,  381,  751. 

§  1395.  Cutis,  skin. — The  skin  or  integument  forms  the  covering 
of  the  entire  body.  It  is  elastic  and  flexible,  tough  and  dense, 
hence  well  adapted  as  a  protecting  envelope.  It  is  continuous 
with  the  mucous  membranes  at  the  various  natural  orifices. 

§  1396.    The  skin  is  composed  of  two  layers,  ectal  and  ental. 

Ectal  Layer,  Epidermis,  Gutide. — Composed  of  nucleated  cells,  those  nearest  the  sur- 
face are  flat ;  the  deeper  ones  are  spherical  or  columnar  and  form  the  Rete  mucosum, 
which  contains  the  coloring  matter  of  the  skin. 

The  function  of  the  epidermis  is  almost  wholly  protective,  and  it  is  devoid  of  sensi- 
bility. 

Ental  Layer,  Derma,  Corium,  Cutis  vera  (true  skin). — The  true  skin  is  composed  of 
elastic  and  white  connective  tissue,  plain  muscles,  blood  vessels,  lymphatics  and  nerves. 
The  principal  function  of  the  Cutis  vera  is  tactile  sensibility  or  the  determination  of  the 
presence  and  character  of  objects  which  come  in  contact  with  the  epidermis. 

Into  it  are  implanted  the  appendages  of  the  skin — hair  and  claws,  sweat  and  sebaceous 
glands. 

The  sweat  glands  serve  to  get  rid  of  some  of  the  waste  products  of  the  body,  while  the 
sebaceous  glands  pour  out  upon  the  surface  an  oily  substance  which  keeps  it  soft  and 
pliable. 

The  hair  and  claws  serve  as  protectors  of  the  body.  The  hair  covers  the  entire  surface 
of  the  body  except  at  the  tip  of  the  snout,  the  pads  of  the  hands  and  feet  and  the  hypoth- 
enar  eminences.  It  protects  the  surface  and  assists  more  or  less  in  touch,  since  a  nervous 
filament  is  connected  with  the  implanted  end  of  each  hair.  In  addition  to  the  ordinary 
hairs  forming  the  protective  covering  of  the  body,  there  are  specialized  hairs  Avhich,  from 
their  connections,  are  undoubtedly  tactile  organs.  These  are  situated,  in  the  cat,  in  the 
dorsal  lip  (Vibrissae,  Fig.  87,  88),  in  the  eyebrows  (Fig.  87,  88),  on  the  side  of  the  face,  in 
the  ventral  lip  and  on  the  antebrachium  (Fig.  76,  105.  pili  tactiles).  They  differ  from 
common  hairs  in  being  longer  and  stiffer,  but  especially  in  being  implanted  very  deeply 
and  in  having  a  larger  nervous  and  vascular  supply. 

For  the  structure  and  presence  of  tactile  hairs  in  various  animals,  see  Owen,  A,  III, 
187 ;  Curtis,  L.,  1, 166;  Schoebl,  lO  ;  Ranvier,  A,  913  ;  Milne-Edwards,  A,  XI,  424.  For 
the  structure  of  the  skin  of  the  dog,  see  Stirling,  1,  465. 

LINGUA— THE  TONGUE. 

References.— Gray,  A,  707 ;  Quain,  A,  II,  325  ;  Dalton,  A,  463,  513 ;  Foster  and 
Langley,  A,  176  ;  Foster,  A,  586 ;  Leyh,  A,  349  ;   Strieker,  A,  353  ;   Chauveau,  A,  355. 


THE    TONGUE    AND    NOSE.  513 

859  ;   Chauvean  (Fleming),  A,  344,  813  ;   Owen,  A,  III,  190  ;   Gurlt,  A,  344,  814;   Milne- 
Edwards,  A,  XI,  437  ;  Bernstein,  A,  295  ;  Flint,  A,  759. 

§  1397.  Lingua,  tongue. — The  tongue  is  the  principal  organ  of 
taste  or  gustation.  It  is  a  very  movable  muscular  organ  covered 
with  mucosa  and  situated  in  the  mouth.  It  is  also  possessed  of  a 
high  degree  of  tactile  sensibility. 

By  its  muscular  structure  it  takes  part  in  the  processes  of  mastication  and  deglutition 
and  in  speech.  To  it  are  distributed  three  nerves,  the  trigeminus  to  the  tip,  the  glosso- 
pharyngeus  to  the  base  and  the  hypoglossus  to  the  muscles.  The  glossopharyngeus  is 
also  distributed  to  the  mucosa  of  the  soft  palate  and  the  pillars  of  the  fauces  ;  hence  their 
mucosa  possesses  a  certain  amount  of  gustatory  sensibility.  The  parts  upon  the  tongue 
supposed  to  be  the  special  seats  of  gustatory  sensibility  are  the  fungiform  and  circumval- 
late  papillcB.     These  are  briefly  described  in  connection  with  Fig.  88,  p.  305. 

For  supposed  gustatory  structures  in  the  epiglottis  of  the  dog  and  cat,  see  Schofield, 
J,  475. 

Demonstration. — The  muscular  structure  of  the  tongue  may  be  made  out  by  such  a 
section  as  that  shown  in  Fig.  88.  The  papillae  may  be  seen  on  such  a  section,  but  better 
on  a  tongue  which  has  been  removed  with  the  mandible.  The  nervous  supply  of  the 
tongue  may  be  determined  by  following  the  general  directions  for  the  dissection  of  nerves ; 
see  also  Fig.  107,  §  1008,  and  for  the  vagus  and  sympathic  (§  1037). 

NASUS— THE  NOSE. 

References. — Gray,  A,  710  ;  Quain,  A,  II,  664  ;  Dalton,  A,  517  ;  Foster  and  Langley, 
A,  176  ;  Foster,  A,  584  ;  HyrtI,  A,  385  ;  Leyh,  A,  349  ;  Strieker,  A,  793  ;  Chauveau,  A, 
466.  863  ;  Chauveau  (Fleming),  A,  439,  815  ;  Owen,  A,  III,  204  ;  Gurlt,  A,  814  ;  Milne- 
Edwards,  A,  XI,  453  ;  Bernstein,  A,  385  ;  Flint,  A,  754. 

§  1398.  Nasus,  nose. — In  Fig.  59  and  88  are  shown  longitudinal  sections  of  the  nasal 
passages.  It  will  be  seen,  especially  in  Fig.  88,  that  there  is  a  tolerably  direct  passage 
from  the  prcenaris  to  the  postnaris  through  the  so  called  meatus  ventralis  (inferior). 
Dorsad  of  the  meatus  ventralis  are  the  turbinated  bones  which  are  most  intricately  con- 
voluted. 

The  membrana  Schneideriana  is  the  mucosa  of  the  nasal  fossae.  Through  the  com- 
paratively minute  spaces  formed  by  the  scrolls  of  the  turbinated  bones,  the  air  may  pass 
from  the  prsB-  to  the  postnaris,  but  its  movement  is  much  slower  than  when  passing 
through  the  meatus  ventralis.  The  forms  of  the  turbinated,  bones  and  the  passages 
through  them  may  be  well  seen  by  transecting  a  cat's  head  just  cephalad  of  the  mesal 
canthi  of  the  eyes  (§  1400).  Through  the  lamina  cribrosa  (Fig.  60)  pass  the  olfactory 
nerves  to  be  distributed  to  the  mucosa  upon  the  ethmo-turbinals  ;  this  mucosa  is  the  seat 
of  the  olfactory  sensibility  proper,  that  is,  of  the  appreciation  and  distinction  of  perfumes 
and  odors.  The  mucosa  of  the  maxillo-turbinals  and  meatus  ventralis  is  supplied  by  ner- 
vous filaments  of  the  nasal  branch  of  the  1st  or  opththalmic  division  of  the  trigeminus 
and  possesses  sensibility  more  like  that  of  the  skin..  It  takes  cognizance  of  the  pungent 
vapors  of  such  substances  as  ammonia. 

The  nervous  supply  of  the  nose  may  be  determined  by  following  the  general  directions 
for  the  dissection  of  nerves  (§  1008). 

33 


514  ANATOMICAL    TECHNOLOGY, 


OCULUS— THE  EYE  AND  ITS   APPENDAGES. 

General  References.— Gray,  A,  713  ;  Quain,  A,  II,  583  ;  Dalton,  A,  519;  Foster  and 
Langley,  A,  178,  244  ;  Hyrtl,  A,  391  ;  Leyh,  A,  323  ;  Straus-Durckheim,  A,  201  ;  Strieker, 
A,  802  ;  Morrell,  A,  260  :  Chauveau,  A,  862  ;  Chanveau  (Fleming),  A,  817  ;  Owen,  A,  III, 
246 ;  Foster,  A,  510  ;  Gurlt,  A,  775  ;  Milne-Edwards,  A,  XII,  94  ;  Bernstein,  A,  48 ;  Flint, 
A  ;  Le  Conte,  A. 

Instruments  and  Material. — Scalpel ;  artlirotome  ;  fine  and  coarse  scissors  ;  fine  and 
coarse  forceps  ;  tracer  ;  flexible  blow- pipe ;  nippers  ;  tripod  lens  ;  beaded  bristles  ;  skull 
prepared  as  in  Fig.  56. 

§  1399.  The  eye  is  the  organ  of  the  sense  of  sight  (§  1394,  D). 
It  is  situated  in  the  orbital  fossa  (Fig.  56),  which  in  the  cat  is  in- 
complete. 

In  connection  with  the  eye  proper  are  certain  appendages  which 
protect,  lubricate  and  move  the  eyeball. 

APPENDAGES  OF  THE  EYE. 

§  1400.  Palpebrse,  eyelids. — The  eyelids  are  modified  folds  of 
skin  which  protect  the  cephalic  surface  of  the  eye.  There  are  two 
for  each  eye,  which  from  their  position  are  called  respectively  the 
dorsal  (upper)  and  ventral  (lower)  lid.  Their  ectal  surface  is  cov- 
ered with  hair,  but  there  are  no  eyelashes  ;  their  ental  surface,  that 
next  the  eyeball,  is  lined  with  a  smooth  mucous  membrane,  the 
conjunctiva  (Fig.  126,  cnjct.). 

The  two  points  where  the  eyelids  meet  are  called  the  canthi  or 
angles  of  the  lids  ;  a  mesal  (inner)  or  nq^sal  and  a  lateral  (outer)  or 
temporal  canthus. 

Dissection  of  the  Lids, — Make  an  incision  through  the  skin 
from  the  angle  of  the  mouth  to  a  point  opposite  the  base  of  the  ear, 
and  th'm  transversely  to  the  dorsimeson.  Then  make  an  incision 
from  the  lateral  canthus  directly  caudad  to  the  transverse  incision. 
Keflect  the  ventral  eyelid  and  the  skin  nearly  to  the  mesal  canthus, 
noting  that  the  smooth  mucous  membrane  (conjunctiva)  lining  the 
lid  is  continuous  with  the  covering  of  the  eyeball  (Fig.  126). 

§  1401.  Meibomian  Glands. — Grasp  the  free  edges  of  the  lids 
and  evert  them.  On  the  mucous  membrane  there  will  be  seen 
many  parallel,  broad,  yellowish  lines,  extending  from  the  edge  of 
the  eyelid  for  about  2  mm.  (Fig.  126).  These  are  the  Meibomian 
glands.  They  secrete  a  sebaceous  substance  which  is  poured  out 
upon  the  edges  of  the  lids  through  minute  orifices  ;  these  may  be 
seen  at  the  top  of  slight  elevations  by  employing  a  tripod  magnifier. 


APPENDAGES     OF    TUE    EVE.  515 

§  1402.  Membrana  nictitans,  third  eyelid  (Fig.  126). —The 
third  eyelid  is  a  fibrous,  crescent-shaped  organ  situated  at  the  mesal 
canthus  between  the  eyelids  proper  and  the  eyeball.  Both  of  its 
surfaces  are  covered  by  a  continuation  of  tlie  conjunctiva.  Its 
cephalic  edge  is  free  and  dark  bordered,  its  caudal  edge  is  flexibly 
attached  to  the  eyeball  (Fig.  126). 

The  oflice  of  the  membrana  is  to  keep  the  eye  free  from  dust. 
The  generalization  made  by  Chauveau.  A,  is,  "That  it  is  most 
developed  in  animals  that  are  unable  to  use  their  cephalic  limbs 
for  removing  foreign  particles  from  the  eye." 

Demonstration. — The  movement  of  the  membrana  depends  upon 
that  of  the  eyeball,  not  upon  the  action  of  special  muscles.  There 
are,  however,  a  few  striated  muscular  fibers  in  the  band  of  connec- 
tive tissue  passing  from  the  rectus  ventralis  to  the  membrana  as 
shown  in  Fig.  126.  If  the  membrana  is  not  visible,  press  upon  the 
cornea  so  as  to  force  the  eyeball  farther  into  the  orbital  fossa,  and 
it  will  appear.  It  may  be  made  to  entirely  cover  the  cornea.  To 
cause  it  to  disappear,  cut  the  masseter  muscle  and  force  a  scalpel 
handle  into  the  orbital  fossa  so  as  to  push  the  eyeball  cephalad. 

§  1403.  Lachrymal  Apparatus. — This  consists  of  the  lachrymal 
or  tear  glands  and  their  ducts.  The  glands  are,  in  general  struc- 
ture, like  the  salivary  glands  (§§  788,  789).  They  are  situated  near 
the  lateral  canthi  of  the  lids. 

Demonstration, — (A)  Glandula  lachry mails,  lachrymal  gland 
proper. — Nip  the  orbital  process  of  the  frontal  and  malar  bones,  cut 
the  soft  parts  connecting  the  malar  process,  and  turn  the  end  dor- 
sad. The  lachrymal  gland  will  cling  to  the  reflected  part.  It  ap- 
pears like  the  molar  gland  (§  785),  and  is  so  formed  as  to  mold 
itself  to  the  eyeball  upon  which  it  naturally  rests. 

(B)  Glandula  Harder i. — Harder' s  gland,  situated  on  the  convex 
or  ectal  surface  of  the  membrana  nictitans,  extends  from  near  its 
attached  border  over  about  one  third  its  width  (Fig.  126).  It  is 
very  apparent  after  the  removal  of  the  eyeball  (§  1415). 

It  is  found  only  in  animals  possessing  the  third  eyelid  (MLlne- 
Edwards,  A,  XII,  121). 

Lachrymal  Canal. — On  the  free  edge  of  each  eyelid,  about  3 
mm.  from  the  nasal  canthus,  is  the  opening  of  a  lachrymal  canal. 
These  canals  collect  the  tears  and  convey  them  to  the  lachrymal 
duct. 

Demonstration. — The  openings  of  the  lachrymal  canals  may 


516  A^'AT03^CAL    TECHNOLOGY, 

be  seen  easily  by  drawing  the  eyelids  well  apart  and  looking  witb  a 
magnifier  at  their  free  edges  near  the  mesal  canthus.  Insert  a 
beaded  bristle  into  each  canal. 

Laclirymal  Duct. — This  is  formed  by  the  nnion  of  the  two  canals 
and  extends  to  the  nasal  cavity.  Its  beginning  is  somewhat  dilated 
and  is  called  the  lachrymal  sac. 

Demonstration. — Slightly  expand  the  prsenaris  and  pnsh  the 
beaded  bristles  mentioned  above  until  they  appear  at  the  nasal 
opening  of  the  lachrymal  dnct.  This  opening  is  jnst  ventrad  of  the 
cartilaginous  prolongation  of  the  maxillo-turbinal  bone  (at  a  point 
ventrad  of  the  M  of  the  abbreviation  "  Mxtrb."  in  Fig.  88).  The 
opening  is  quite  large  and  will  readily  receive  the  probe  of  the  tracer. 
If  it  is  desirable  to  trace  the  lachrymal  duct  throughout  its  course, 
a  bristle  should  be  put  into  it.  Then  the  head  should  be  hemi- 
sected.  and  the  duct  traced  with  nippers  and  arthrotome,  com- 
mencing at  its  nasal  termination. 

MUSCLES  OF  THE  EYE. 

The  cat's  eye  possesses  12  muscles,  ten  belonging  to  the  eyeball 
(4  recti^  4  cJioanoid,  the  trochlearis  and  the  ohliquus  centralis),  and 
2  to  the  lids — orMcularis  palpebrarum  (§  1404)  and  levator  palpe- 
hrce  dorsalis  (§  1409).  Besides  the  special  muscles  of  the  eyelids, 
the  muscles  of  the  face  assist  and  modify  their  movements. 

§  1404.  M.  orbicularis  palpebrarum  (Fig.  126,  M.  orb.  plpbr). 
— This  is  the  circular  muscle  surroundipg  both  lids  and  serving  to 
close  them.  To  demonstrate  it,  cut  either  of  the  lids  transversely. 
Just  entad  of  the  skin  will  be  seen  the  cut  ends  of  a  thin  layer  of 
pale,  striated  muscular  fibers.  The  fibers  are  plentifully  mixed 
with  elastic  and  white  connective  tissue. 

For  the  M.  levator  palpebrse  dorsalis,  see  §  1409. 

§  1405.  Exposure  of  the  Muscles  of  the  Eyeball. — These  as 
well  as  the  levator  palpehrce  are  within  the  orbital  fossa.  To  expose 
them,  cut  with  nippers  the  two  ends  of  the  zygoma  (Fig.  ^Q).  Grasp 
the  orbital  process  with  the  forceps  and  lateriduct  it.  At  the  same 
time  sever  the  soft  parts  close  to  the  bone  with  an  arthrotome,  so 
that  the  zygoma  can  be  removed.  Remove  the  temporal  and  mas- 
seter  muscles  by  grasping  their  cephalic  edge  and  severing  the 
attachments.  In  doing  this,  be  very  careful  not  to  include  any  of 
the  fibrous  capsule  of  the  eye.  After  these  muscles  are  removed, 
nip  away  half  of  the  mandible  ;  then  remove  the  part  of  the  maxilla 


MUSCLES    OF    THE    EYE.  517 

containing  the  molar  and  the  last  or  largest  prsemolar  tooth.  This 
will  expose  the  lateral  aspect  of  the  eyeball  and  a  muscle  (ptery- 
goid) extending  obliquely  from  the  mandible  to  the  floor  of  the 
orbit.  There  is  also  brought  clearly  into  view  the  superior  max- 
illary artery  and  the  superior  maxillary  division  of  the  5th  nerve. 
Both  extend  along  the  floor  of  the  orbit  laterad  of  the  eyeball  to  the 
infraorbital  foramen  (Fig.  60,  Fm.  inf.  or.),  from  which  point  they 
are  called  infraorbital  artery  and  nerve.  They  should  be  carefully 
removed.  Two  of  the  muscles  of  the  eyeball  will  appear,  M.  rectus 
ventralis,  M.  rectus  lateralis.  Raise  the  eyeball  somewhat  with 
a  scalpel  handle  and  cut  the  pterygoid  muscle  at  its  origin  in  the 
floor  of  the  orbit.  Note  that  the  edges  of  the  recti  muscles  slightly 
overlap  near  their  origin,  but  separate  like  the  sepals  of  a  flower  as 
they  extend  cephalad  toward  the  eyeball.  Separate  them,  and 
trace  first  the  M.  rectus  lateralis  to  its  attachment  on  the  eyeball, 
removing  the  loose  fibrous  substance  with  scissors.  Do  not  injure 
the  tendon  of  the  ventral  oblique  (see  §  1406). 

Pass  a  scalpel  handle  entad  of  the  free  edge  of  the  muscle,  raise 
it  and  free  it  from  the  underlying  tissue  with  a  tracer.  When  free, 
raise  the  muscle  by  the  scalpel  handle  and  make  it  tense.  It  will 
be  seen  to  terminate  in  a  broad  ribbon-like  tendon  which  is  inserted 
into  the  sclerotic  at  the  caudal  margin  of  the  white  zone  of  the  eye- 
ball (Fig.  126,  Z.  a.). 

§  1406.  M.  obliquus  ventralis  (inferior),  the  ventral  or  inferior 
oblique  muscle. — In  clearing  away  the  fibrous  tissue  from  the  ball 
to  expose  the  lateral  rectus,  this  muscle  also  will  be  exposed.  It 
appears  as  a  circular  band  overlapping  the  ventral  rectus.  Sepa- 
rate the  body  of  the  muscle  from  the  other  tissues,  and  lift  it  up 
with  the  scalpel  handle  as  for  the  lateral  rectus,  and  it  will  be  seen 
to  insert  itself  by  a  broad  tendon  along  the  edge  and  cephalad  of 
the  tendon  of  the  lateral  rectus.  The  tendons  of  these  two  muscles 
form  a  right  angle.  Raise  the  eyeball  with  a  scalpel  handle  and 
trace  the  ventral  oblique  to  its  origin  from  the  orbital  surface  of  the 
maxilla  just  laterad  of  the  Os  lachrymale  (just  laterad  of  the  "h" 
of  the  abbreviation  "  O.  Ich."  in  Fig.  5Q>). 

%  1407.  M.  rectus  ventralis  (inferior),  (Fig.  126,  M.  r.  vntr.).— 
This  appears  on  the  ventral  side  of  the  eyeball.  Draw  it  out  so  as 
to  show  the  attachment ;  then  dissect  the  body  of  this  muscle  as 
directed  for  the  lateral  rectus,  and  raise  it  in  order  to  note  its  inser- 


518  ANATOMICAL    TECHNOLOGY. 

tion  at  the  caudal  margin  of  the  white  zone  as  with  the  lateral  rec- 
tus (Fig.  126). 

§  1408.  M.  rectus  dorsalis  (superior),  (Fig.  126,  M.  r.  drsl.).— 
Cut  for  about  1  cm.,  close  to  the  bone,  the  fibrous  band  holding 
the  eyeball  to  the  postorbital  process  of  the  frontal.  Draw  the  eye- 
ball cephalad,  and  the  dorsal  rectus  will  appear  on  the  dorsal  side 
of  the  eyeball.  Dissect  it  as  described  for  the  others  (§  1405),  and 
note  that  its  insertion  is  at  the  same  level  on  the  eyeball,  as  shown 
in  Fig.  126. 

A  considerable  band  passes  from  the  ventral  rectus  to  the  Mem- 
brana  nictitans.  This  is  composed  mostly  of  connective  tissue,  but 
with  the  microscope  a  small  number  of  muscular  fibers  may  be 
found  in  it.     It  is  thus  a  retractor  of  the  Membrana  nictitans. 

§  1409.  M.  levator  palpebrse  dorsalis  (superioris). — This  very 
thin,  slender  muscle  may  be  seen  by  grasping  some  of  the  fibrous 
substance  near  the  cornea  and  drawing  the  ball  cephalo-ventrad. 
It  is  on  the  ectal  surface  of  the  dorsal  rectus  for  the  first  fourth  of 
its  length,  then  it  inclines  mesad.  Isolate  it  with  the  greatest  care. 
About  opposite  the  point  of  insertion  it  spreads  out  into  a  broad 
tendon,  which  is  attached  to  the  dorsal  lid  (Fig.  126).  Grasp  the 
edge  of  the  dorsal  lid  and  raise  it  from  the  ball ;  then  pull  upon  the 
muscle,  and  the  traction  can  be  seen  on  the  ental  surface  of  the  lid. 

§  1410.  M.  rectus  mesalis  (internus).  —  Divide  the  ventral 
oblique  and  sever  the  fibrous  connection  of  the  eyeball  with  the 
orbital  fossa  on  the  ventral  side  to  a  point  about  opposite  the  open- 
ing of  the  lachrymal  canal  on  the  dorsal  lid  ;  then  evert  the  Mem- 
brana nictitans  and  draw  the  eyeball  laterad.  This  will  expose  the 
mesal  rectus.  Its  attachment  to  the  eyeball  should  be  determined 
as  described  in  §  1405. 

§  1411.  M.  trochlearis  s,  obliquus  dorsalis  (superior). — This 
muscle  will  appear  mesad  of  the  rectus  mesalis.  Draw  the  eyeball 
caudad  and  laterad  and  isolate  the  muscle  from  its  origin  toward  its 
insertion.  When  about  opposite  the  middle  of  the  eyeball,  it 
merges  into  a  slender  tendon  which  extends  to  a  point  a  little  cau- 
dad and  entad  of  the  mesal  canthus,  where  it  passes  through  a 
fibro-cartilaginous  ring.  This  ring  is  held  somewhat  loosely  to  the 
bony  orbit,  nearly  directly  opposite  the  origin  of  the  ventral 
oblique,  by  a  strong  fibrous  band  about  4  mm.  long  extending 
directly  dorsad,  and  a  slender  one  about  25  mm.  long  attached  to 


MUSCLES     OF    TUE    EYE.  519 

the  postorbital  process  of  the  frontal  (Fig.  6Q^  Pre.  po.).  To  demon- 
strate these  bands,  draw  the  eyeball  laterad  and  pull  upon  the 
fibro-cartilaginous  pulley.  The  tense  lines  show  the  direction  of 
the  bands  and  serve  as  guides  in  isolating  them.  Continue  to  draw 
the  ball  laterad  and  isolate  the  tendon  of  the  M.  troclilearis  after  it 
passes  the  pulley.  Draw  it  taut  and  it  will  be  seen  to  pass  directly 
laterad  toward  the  eyeball.  It  passes  entad  of  the  M.  levator  pal- 
pebrse  and  then  expands  into  a  thin  sheet  which  is  inserted  into  the 
eyeball  at  right  angles  to  the  insertion  of  the  dorsal  rectus,  as  the 
ventral  oblique  is  inserted  into  the  ball  at  right  angles  to  the  lateral 
rectus  (§  1406). 

§  1412.  MM.  choanoidei,  s.  M.  choanoideus,  s.  MM.  recti 
minores,  s.  MM.  recti  posteriores,  s.  M.  suspensor  oculi. — These 
are  four  straight  muscles  like  the  recti  proper,  but.  smaller.  They 
may  be  demonstrated  by  separating  the  recti  muscles.  They  will 
be  seen  to  alternate  with  the  recti  as  they  extend  along  the  eyeball 
to  their  insertion,  which  is  by  a  broad,  thin  tendon  near  the  middle 
of  the  eyeball.  This  is  true  of  all  but  the  ventral  (inferior)  one, 
whose  tendon,  like  those  of  the  recti,  is  inserted  into  the  edge  of  the 
white  zone  of  the  sclerotic  (Fig.  126). 

§  1413.  Origin  of  the  Muscles  of  the  Eye. — All  of  the  muscles 
of  the  eye  described  above,  except  the  orbicularis  palpebrarum 
(§  1404)  and  the  obliquus  centralis  (§  1406),  arise  in  a  circle  sur- 
rounding the  optic  nerve  at  its  exit  from  the  skull,  thus  forming  for 
it  a  muscular  sheath. 

The  levator  palpebrce  dorsalis  arises  near  the  sutura  fronto- 
orbito-sphenoidea,  dorsad  of  the  origin  of  the  dorsal  rectus,  which 
arises  very  near  the  foramen  opticum. 

The  trocJilearis  is  in  like  manner  ectad  of  the  mesal  rectus. 

The  lateral  rectus  passes  between  the  tendon  of  the  ventral  rec- 
tus and  the  combined  tendon  of  the  choanoid  muscles  to  be  inserted 
into  the  septum  between  the  optic  and  anterior  lacerated  foramina. 

The  ventral  rectus  arises  from  the  lateral  and  ventral  aspects  of 
the  foramen  lacerum  anterius,  and  just  ectad  of  its  origin  is  the 
common  tendon  of  the  four  clioanoid  muscles  (Fig.  126). 

In  determining  the  origin  of  the  muscles,  the  connections  of  the 
eyeball  should  be  so  far  separated  from  the  socket  that  one  may 
work  in  any  part  of  the  orbital  fossa  without  difficulty. 

§  1414.   Action  of  the  Muscles  of  the  Eye. — With  the  recti  this  is  probably  as  in 
man,  viz. ,  that  they  move  the  eye  in  the  direction  of  the  four  cardinal  points  according  to 


520  ANATOMICAL    TECHNOLOGY, 

their  attachment.  The  oblique  muscles  are  so  differently  attached  from  those  in  man  that 
the  action  could  hardly  be  the  same  (Quain,  A,  I,  277).  It  would  seem  from  the  anatomi- 
cal arrangement  that  the  ventral  oblique  would  simply  rotate  the  eyeball  laterad  and  the 
trochlearis  would  rotate  it  mesad. 

§  1415.  The  nervous  supply  is  given  in  the  Table  of  cranial  nerves  (§  1392),  distri- 
bution of  the  3d,  4th,  6th  and  7th  nerves.  The  nerves  may  be  made  out  on  a  fresh  or  alco- 
holic specimen  by  following  the  general  directions  for  dissecting  nerves  in  §§  1008,  1087. 

GLOBUS  OCULI— EYEBALL. 

§  1416.  How  to  Obtain  the  Eyeball. — The  one  exposed  in  dis- 
secting the  muscles  may  be  severed  from  the  head  by  cutting  the 
muscles  near  their  middle  and  the  optic  nerve  about  1  cm.  from  the 
ball ;  or  a  fresh  eye  may  be  exposed  as  described  for  studying  the 
muscles  (§  1405)  and  then  severed  as  just  described.  In  case  it  is 
undesirable  to  injure  the  skull,  or  the  eye  of  an  ox  or  sheep  is  to 
be  obtained,  grasp  the  lids  successively,  and  turning  the  concavity 
of  the  curved  scissors  toward  the  eyeball,  sever  the  connection  with 
the  lids.  G-rasp  the  membrana  nictitans  and  draw  the  eyeball 
cephalad.  Keeping  the  concavity  of  the  scissors  toward  the  ball, 
cut  its  fibrous  and  muscular  connections  with  the  orbit ;  cut  also 
the  optic  nerve  about  1  cm.  from  the  ball. 

After  the  eyeball  is  removed,  carefully  free  it  from  all  tissue 
except  the  membrana  nictitans  and  the  lateral  and  dorsal  recti 
muscles.  These  should  be  left  to  enable  one  to  determine  the 
aspect  of  the  eye. 

§  1417.  Note  the  following :— (A)  In  form,  the  eyeball  of  the  cat 
is  spheroidal  and  somewhat  pointed  cephalad  (Fig.  126).  (B)  The 
cephalic  third  {cornea,  %  1421)  is  transparent  and  continuous  with  (C) 
the  sclerotica  (§  1421),  which  forms  the  rest  of  the  ectal  wall  of  the 
eyeball.  (D)  iK  opticus,  at  the  caudal  part  of  the  eyeball  enters 
the  large  cylindrical  optic  nerve. 

§  1418.  Iris  et  Pupilla  (Fig.  126). — Upon  looking  into  the  cor- 
nea there  will  be  seen  a  golden-yellow  circular  curtain,  the  iris. 
This  curtain  is  not  complete,  but  in  the  middle  is  an  opening,  the 
pupil.  The  form  of  the  pupil  in  the  cat  is  circular  when  fully 
dilated,  as  in  a  cat  killed  with  chloroform.  When  partly  contracted 
it  is  elliptical,  but  when  fully  contracted  it  is  a  dorso- ventral  slit. 
These  various  forms  are  readily  seen  in  a  living  cat's  eye  by  trans- 
ferring the  cat  from  a  dim  into  a  brilliant  light. 

§  1419.  Images  Formed  by  the  Eye. — If  the  eye  is  perfectly 
fresh,  so  that  the  cornea  is  transparent,  rub  some  strong  glycerin  on 


COATS    OF    THE    EYEBALL.  521 

the  caudal  part  of  the  sclerotic  to  make  it  transparent ;  hold  the 
eye  with  the  cornea  toward  a  well-lighted  window  or  a  lamp  flame. 
The  image  of  the  window  or  flame  will  be  seen  on  the  caudal  aspect 
of  the  eyeball ;  the  image  is  real,  and  hence  inverted  like  that 
formed  by  a  photographer's  camera.  Raise  or  lower  the  eyeball, 
and  the  image  will  be  seen  to  move  in  the  opposite  direction.  If  the 
eye  of  a  large  animal  is  used  for  this  experiment,  a  piece  must  be 
removed  from  the  caudal  part  of  the  sclerotic  on  account  of  its 
opacity. 

§  1420.  TunicsB  oculi— Coats  of  the  eye  (Fig.  126).— For  the 
study  of  the  remaining  parts  of  the  eye,  a  fresh  one  may  be  used, 
but  one  hardened  in  alcohol  is  desirable,  as  such  a  one  retains  its 
form  and  the  various  parts  are  less  easily  torn  and  displaced.  To 
harden  an  eye,  cut  a  slit  in  the  sclerotic  at  one  side  and  place  the 
eye  on  absorbent  cotton  in  62  per  cent,  alcohol  for  a  day ;  theu 
remove  to  95  per  cent,  for  two  days  or  more. 

Dissection. — With  forceps  and  scissors  make  an  incision  from 
about  the  middle  of  the  cornea  to  near  the  optic  nerve,  taking  care 
to  cut  only  through  the  wall.  Connect  the  same  two  points  by 
another  incision  in  such  a  way  as  to  remove  a  segment  containing 
one  fourth  or  one  fifth  of  the  entire  wall  of  the  globe.  In  this  seg- 
ment the  different  tunics  may  be  studied. 

§  1421.  Sclerotica  et  Cornea  (Fig.  126).— Together  these  form 
the  ectal  covering  or  framework  of  the  eyeball. 

The  sclerotic  covers  the  caudal  three  fourths  of  the  eyeball  and 
becomes  thickened  before  merging  into  the  cornea.  This  thicken- 
ing has  the  appearance  of  a  white  band  around  the  eyeball,  and 
for  convenience  may  be  called  the  Zona  alba  (Fig.  126,  Z.  a.)  or 
white  zone.  At  the  caudal  margin  of  this  zone  are  inserted  the  recti 
muscles.     Its  width  indicates  the  length  of  the  plicce  ciliares  (§  1422). 

In  the  ental  wall  of  the  sclerotic  are  many  pigment  cells  {lamina 
fused),  giving  it  a  dark  appearance  ;  and  on  the  line  where  it 
merges  into  the  cornea  these  pigment  cells  extend  through  to  the 
ectal  wall  of  the  sclerotic.  The  cornea  completes  the  framework  of 
the  eyeball  cephalad.  It  is  transparent  and  intermediate  in  thick- 
ness between  that  of  the  white  zone  and  the  rest  of  the  sclerotic. 

§  1422.   Ohoroidea  (Fig.  126).— The  choroid  coat  of  the  eye  is 
just  entad  of  the  sclerotic.     It  is  a  vascular  coat,  but  contains  also)( 
much  pigment,  hence  its  dark  appearance.     AVith  a  tracer  separate 
the  choroid  and  sclerotic  as  shown  in  Fig.  126.     The  choroid  does 


V. 


522  ANATOMICAL    TECHNOLOGY. 

not  extend  cephalad  of  the  iris.  Opposite  the  white  zone  it  is  folded 
into  plaits  (Plicae  ciliares,  Fig.  126).  There  are  about  seventy  of 
these  plaits  or  folds. 

§  1423.  Iris. — The  iris,  as  stated  above,  is  the  circular  perforated 
curtain  caudad  of  the  cornea.  Its  caudal  surface  is  black,  its 
cephalic  a  golden  yellow,  which  gives  color  to  the  eye.  It  is  at- 
tached at  its  circumference  to  the  choroid ea,  the  cornea  and  the 
sclerotic. 

§  1424.  Retina  (Fig.  126). — The  retina  is  the  ental  coat  or  tunic 
of  the  eye.  It  is  an  expansion  of  the  optic  nerve  to  which  are  added 
nerve  cells  and  various  other  parts  (see  Quain,  A,  II,  605).  It  is  the 
sensitive  part  of  the  organ  of  sight.  It  may  be  separated  from  the 
choroid  as  shown  in  Fig.  126  by  using  a  scalpel  handle.  Note  tliat 
it  is  of  nearly  uniform  thickness  until  it  reaches  the  margin  of  the 
ciliary  folds,  Or  a  serrata  (Fig.  126).  Its  extension  upon  the  folds 
becomes  thin  and  is  called  the  Pars  ciliaris  retince.  The  entrance 
of  the  optic  nerve  appears  as  a  round  white  spot,  discus  opticus 
(blind  spot). 

§  1425.  Tapetum  (Fig.  126). — In  the  eye  of  the  cat,  as  in  many 
other  animals,  the  retina  does  not  contain  pigment  over  its  whole 
extent,  but  is  devoid  of  it  in  its  dorso-mesal  part.  Here  the  cho- 
roid is  brilliantly  colored,  forming  the  so  called  Tapetum,  The 
color  is  metallic  golden-blue  green.  In  this  part  of  the  choroid  is  a 
deposit  of  mineral  salts  of  calcium  which  assists  in  giving  the  lumi- 
nous appearance  to  the  cat' s  eye  in  a  dim  light  (Milne-Edwards,  XII). 

§  1426.  Humor  aqueus. — The  aqueous  humor  is  a  clear  watery 
fluid  which  fills  the  space  between  the  corne#and  the  iris  and  lens 
and  also  the  small  space  between  the  iris  and  the  plicae  ciliares  (Fig. 
126).  These  spaces  are  called,  from  their  position,  Camera  aquosa 
cepJialica  (anterior),  cephalic  or  anterior  aqueous  chamber  (Fig.  126, 
C.  aq.),  and  Camera  aquosa  caudalis  (posterior),  caudal  or  post^or 
aqueous  chamber  (Fig.  126,  C.  a.). 

§  1427.  The  corpus  vitreum  or  vitreous  humor  is  a  transparent 
jelly-like  substance  occupying  the  greater  space  of  the  eyeball.  It 
is  bounded  cephalad  by  the  lens  and  ciliary  processes  and  at  all 
other  points  by  the  walls  of  the  eyeball.  ^ 

§  1428.  Lens  (lens  crystallina)— Crystalline  lens  (Fig.  126).— 
The  lens  is  the  double  convex  transparent  body  situated  between  the 
aqueous  chambers  and  the  vitreous  body.     Its  cephalic  convexity 


DOESO- VENTRAL    SECTION    OF    THE    EYE.  523 

is  greater  than  its  caudal.  In  the  fresh  eye  it  is  perfectly  transpar- 
ent, and  its  ectal  part  is  soft,  while  its  ental  part  is  firmer.  In  an 
alcoholic  eye  it  is  hard  and  mostly  opaque. 

§  1429.  Capsula  lentis  (Fig.  126,  Cpsl.). — This  is  the  sac  surround- 
ing the  lens.  Grasp  the  cut  edges  of  the  white  zone,  and  attemj3t 
to  spread  the  eyeball  out  flat.  There  will  be  seen  a  tense  line  pass- 
ing from  the  plicae  ciliares  to  the  edge  of  the  lens.  At  the  same 
time  look  at  the  lens,  and  there  will  be  seen  enveloping  it  a  thin 
transparent  membrane,  which  is  the  capsule.  Blow  with  a  blow- 
pipe (Fig.  19)  against  the  lens  where  the  tense  line  is  attached,  and 
the  air  will  get  between  the  lens  and  its  capsule,  thus  making  the 
latter  very  evident. 

§  1430.  Zonula  Zinnii,  s.  Ligamentum  suspensorium  (Fig.  126, 
Z.  Z.). — This  is  the  fibrous  connection  of  the  lens  capsule  with  the 
plicae  ciliares.  By  pulling  upon  the  lens  capsule  and  the  sclerotic, 
this  suspensory  ligament  will  be  seen  attaching  itself  to  the  Ciliary 
plicce  (Fig.  126). 

Preparation  of  Fig.  126. — A  cat's  head  was  removed  and  frozen  solid.  The  skin  was 
cut  with  a  scalpel  along  the  dorsal  surface  of  the  head  to  indicate  the  direction  of  the  sec- 
tion. Then  the  section  was  made  with  a  fine  tooth  back-saw  (Fig.  21).  The  debris  was 
removed  by  carefully  scraping  with  a  scalpel,  and  the  outlines  were  obtained  immediately 
by  means  of  a  photographer's  camera.  The  relative  position,  size,  insertion  and  origin  of 
the  muscles  were  obtained  by  subsequent  careful  dissection  on  several  specimens.  The 
form  of  the  eyeball  and  the  relations  of  the  parts  were  verified  on  six  eyes  by  carefully 
removing  and  freezing  them  and  then  making  sections  with  a  watch-spring  saw. 

The  plicoR  ciliares  (P.  c.)  are  about  70  in  number,  but  in  order  that  they  might  be  shown 
distinctly  only  a  few  of  them  were  drawn.  The  ciliary  musde  in  the  cat  has  not  been  sat- 
isfactorily worked  out,  hence  .jy;s  limits  and  size  have  not  been  clearly  indicated  in  the  figure. 
On  the  ventral  side  the  retina  and  choroidea  are  shown  as  separated  from  the  sclerotica 
and  from  each  other.  Finally,  the  muscles  of  the  head  closely  related  to  the  M.  orbicu- 
laris palpebrarum  have  not  been  indicated. 

Description  of  Fig.  126. — Camera  aquosa  posterior  (C.  a.). — The  posterior  (caudal) 
aqu^us  chamber.     It  is  situated  between  the  Zonula  Zinnii  and  the  iris. 

Camera  aquosa  anterior  (C.  aq.). — The  anterior  (cephalic)  aqueous  chamber.  It  is 
bounded  by  the  lens,  iris  and  cornea. 

Canalis  Schlemmii  (Cn.  Shim.). — The  canal  of  Scblemm  in  the  cat  is  double  and  often 
triple.     It  is  a  venous  sinus. 

Capsula  (Cpsl.).— Capsule  of  the  lens.  This  is  an  elastic  sac  completely  inclosing  the 
lens.     To  it  is  attached  the  suspensory  ligament  or  zone  of  Zinn. 

Choroidea,  s.  Tunica  vasculosa. — This  is  the  dark  brown  membrane  composed  chiefly 
of  blood  vessels  and  lying  between  the  sclerotica  and  retina.  It  extends  cephalad  to  the 
iris.  Opposite  the  zona  alba  of  t]?e  sclerotica  the  choroidea  is  plaited  or  folded,  forming 
the  jylicm  ciliares  or  ciliarj  processes. 

Conjunctiva  (Cnjct.). — The  conjunctiva  is  the  mucosa  lining  the  lids,  covering  both 


524 


ANATOMICAL    TECHNOLOGY. 


Fig.  126.— -DoRSO-VENTRAii  (Vertical)  Section  op  the  Cat's  Left  Eye,  in  situ. 

X  about  2.5. 


surfaces  of  the  membrana  nictitans  and  the  cephalic  surface  of  the  eyeball.  It  is  indicated 
by  oblique  cross  lines. 

Cornea. — The  transparent  cephalic  part  of  the  eyeball.  It  is  a  continuation  of  the 
sclerotica.     Their  junction  is  indicated  by  a  dark  band. 

Foramen  opticum  (Fm.  op.). — Foramen  for  the  optic  nerve  (Fig,  57,  §  562). 

Foramen  lacerum  anterius  (Fm.  1.  a.)  s.  Fissura  sphenoidalis.— A  great  many 
structures  traverse  this  foramen  (§  562),  and  from  its  lateral  wall  arise  the  ventral  rectus 
and  the  choanoid  muscles. 

Foramen  rotundum  (Fm.  rt.),  (§  562). 

Glandula  Meibomiana  (Gl.  M.).— The  Meibomian  glands  (§  1401)  pour  out  a  seba- 
ceous substance  on  the  edge  of  the  lids. 


DORSO-VENTRAL    SECTION    OF    THE    EYE.  525 

Glandiila  Harden  (GI.  Harder). — A  small  laclirymal  gland  pouring  out  a  lubricator 
on  the  ental  or  concave  surface  of  the  Mb.  nictitans  {%  140o,  B). 

Iris. — This  is  the  contractile  diaphragm  justcephalad  of  the  lens.  Its  cut  edges  are 
shown  in  the  fijfure,  and  it  is  represented  as  dilated  to  a  circle  (§  1418).  Its  muscles  are 
of  the  unstriped  variety,  yet  they  act  rapidly  and  appear  as  if  almost  voluntary  in  the  cat. 

Lens. — The  lens  in  the  cat  is  double  convex  as  in  man,  but  unlike  the  human  lens, 
that  of  the  cat  is  the  more  convex  cephalad  (§  1428). 

Discus  opticus  (Mel.). — The  white  or  blind  spot  of  the  eye.  It  is  the  end  of  the 
optic  nerve  as  it  enters  the  eyeball. 

Membrana  (Mb.)  nictitans.— This  is  the  internal  or  third  eyelid.  It  has  a  black  free 
border  (§  1402). 

Mucosa. — Mucous  membrane  of  the  roof  of  the  mouth. 

M.  ciliaris  (M.  c). — The  ciliary  muscle.  This  is  attached  to  the  sclerotica  and  cho- 
roidea.  By  its  contraction  and  relaxation  the  lens  is  made  more  or  less  convex,  and  hence 
accommodates  the  eye  for  near  or  distant  objects.  The  limits  of  this  muscle  have  not 
been  satisfactorily  determined  in  the  cat. 

M.  levator  palpebrae  dorsalis  (M.  Iv.  plpbr.). — The  elevator  of  the  dorsal  (superior, 
upper)  lid  is  a  slender  muscle.     It  must  be  greatly  aided  by  the  ectal  muscles  of  the  head. 

M.  rectus  dorsalis  (superior),  (M.  r.  drsl.). — The  dorsal  straight  muscle  of  the  eye. 
It  is  cut  longitudinally,  hence  its  tendon  is  seen  on  edge. 

M.  rectus  lateralis  (externus),  (M.  r.  Itrl.). — The  muscle  is  cut  and  reflected  ventrad 
to  show  its  origin  from  the  bony  septum  between  the  Fm.  op.  and  Fm.  1.  a.,  and  also  that 
it  is  between  the  tendon  of  the  ventral  rectus  and  the  common  tendon  of  the  choanoid 
muscles  (§  1405). 

M.  rectus  ventralis  (inferior),  (M.  r.  vntr.). — The  ventral  rectus  has  been  divided 
longitudinally  and  is  seen  on  edge.     Its  origin  is  from  the  lateral  wall  of  the  Fm.  1.  a. 

M.  choanoideus  mesalis  (M.  ch.  ra.). — The  tendon  of  this  muscle  crosses  the  optic 
nerve  as  shown. 

M.  choanoideus  dorsalis  (M.  ch.  drsl.). — This  muscle  and  its  tendon  are  seen  on  edge. 

M.  choanoideus  lateralis  (M.  ch,  1.). — The  tendon  of  this  muscle  is  seen  in  its  width. 

M.  choanoideus  ventralis  (M.  ch.  vntr.). — The  ventral  of  the  choanoid  muscles. 
The  common  tendon  of  the  choanoids  seems  to  be  a  continuation  of  this  as  it  goes  to  it? 
origin  from  the  Fm.  1.  a.  (§  1413). 

M.  obliquus  ventralis  (inferior),  (M.  oblq.  vntr.). — The  cut  end  of  the  ventral  oblique 
muscle  (§  1406). 

M.  orbicularis  palpebrarum  (M.  orb.  plpbr.). — The  cut  ends  of  this  circular  muscle 
are  shown  in  each  lid.  The  ectal  muscles  of  the  head  mingle  with  this,  but  they  are 
omitted  from  the  figure. 

M.  pterygoideus. — This  corresponds  to  the  external  pterygoid  of  man.  It  passes  from 
the  O.  palatinum  to  the  mesal  side  of  the  mandible  (Straus-Durckheim,  A,  II,  217). 

N.  maxillaris  superior  (N.  mx.  spr.). — The  second  division  of  the  trigeminus  nerve. 
Its  distribution  is  given  in  the  Table  (§  1392). 

N.  opticus  (N.  op.).— The  optic  nerve  is  seen  traversing  the  optic  foramen  on  its  way 
to  the  eyeball.     It  is  surrounded  by  dura  which  is  continuous  with  the  sclerotica. 

Ora  serrata  (Ora  sr.). — The  retina  at  the  beginning  of  the  ciliary  plicae  becomes  thin, 
and,  as  in  man  it  is  somewhat  indented,  it  is  called  ora  serrata.  The  serrated  appearance 
is  not  marked  in  the  cat.  The  retina  is  very  thin  from  the  ora  to  the  tips  of  the  ciliary 
processes,  where  it  ceases.    This  part  of  the  retina  is  called  the  pars  ciliaris  retinae  (§  1424). 

O.  frontis.— The  frontal  bone  (§  516). 

O.  orbito-sphenoideum  (O   orsph.),  (§  515). 


526  .  ANATOMICAL    TECBNOhOGT. 

Palpebra  dorsalis. — The  dorsal  (superior  or  upper)  eyelid.  The  dorsal  lid  does  not 
contain  a  tarsal  cartilage  as  in  man  (Quain,  A,  11,  584),  and  there  are  no  eyelashes  (cilia) 
(§  1400). 

Palpebra  ventralis  (Plpbr.  vntr.). — The  ventral  (inferior)  or  lower  lid,  like  the  dorsal, 
possesses  no  lashes  (§  1400). 

Pili  tactiles. — Tactile  hairs.  The  bulb  of  one  is  shown  to  indicate  its  great  size  and 
deep  implantation  (§  1396). 

Plicae  ciliares  (P.  c.)  s.  processus  ciliares,  ciliary  plicae  or  processes, — They  are  foldings 
of  the  choroidea.  The  abbreviation  is  written  on  one  shown  in  its  full  extent.  It  is  approx- 
imately triangular  in  outline,  and  to  its  tip  is  attached  the  zonula  of  Zinn,  and  into  it  pass 
many  strong  bands  forming  part  of  the  suspensory  ligament.  The  folds  bifurcate  caudad 
and  gradually  merge  into  the  general  surface  of  the  choroid  (§  1422). 

Retina. — The  nervous  tunic  of  the  eye.  It  is  the  ental  of  the  three  coats.  In  the 
figure  its  cut  edge  is  crossed  by  lines,  and  on  the  ventral  side  it  is  drawn  away  from  the 
choroid  and  toward  the  center  of  the  eye  (§  1424). 

Sclerotica. — This  with  the  cornea  forms  the  ectal  coat  of  the  eye.  In  the  cat  it  is 
very  thin  except  opposite  the  iris  and  ciliary  piic8B.  Here  it  is  thickened  and  has  been 
termed,  provisionally,  Zona  alba  (§  1421). 

Tapetum. — The  brilliantly  colored  part  of  the  ental  surface  of  the  choroidea  (§  1425). 

Vitreum. — The  vitreous  body  or  vitreous  humor.  It  fills  the  entire  space  caudad  of 
the  lens  and  zonula  of  Zinn.  It  is  clear  and  somewhat  jelly-like.  The  canal  of  Petit  is 
merely  an  interval  between  the  vitreum  and  the  zonula.  As  it  is  not  supposed  to  exist 
during  life,  and  certainly  did  not  appear  in  the  sections  of  the  frozen  eye,  it  has  been 
omitted. 

Zona  alba  (Z.  a.). — This  is  a  thickening  of  the  sclerotica  giving  firmness  to  the  eye- 
ball.    Into  its  caudal  edge  are  attached  the  recti  muscles  (§§  1407,  1408). 

Zonula  Zinnii  (Z.  Z.)  s.  Ligamentum  suspensorium  lentis. — The  suspensory  ligament 
in  the  cat  is  attached  to  the  lens  capsule  at  the  edge  of  the  lens  and  passes  not  only  to  the 
summits  of  the  ciliary  processes,  but  into  their  substance  as  shown  in  the  figure.  More- 
over, there  is  an  especially  strong  part  of  the  ligament  opposite  the  summit  of  each  ciliary 
process. 

AURIS— ORGANUM  AUDITUS— EAR.    (Fig.  127,  128.) 

General  References.— Gray,  A,  729  ;  Quain,  A,  II,  626  ;  Dalton,  A,  554 ;  Flint,  A  ; 
Foster  and  Langley,  A,  201  ;  Foster,  A,  574  ;  Hyrtl,  A,  413  ;  Leyh,  A,  338 ;  Strieker,  A, 
950  ;  Chauveau,  A,  880  ;  Chauveau  (Fleming),  A,  846  ;  Owen,  A,  III,  235  ;  Gurlt,  A,  79, 
799 ;  Milne-Edwards,  A,  XII,  1 ;  Bernstein,  A,  164. 

Instruments  and  Material.  —  Watch  spring  saw  ;  nippers  ;  dissecting  instruments 
(g  181)  ;  tripod  magnifier  ;  15  per  cent,  glycerin  ;  cat's  head  ;  macerated  skull  prepared  as 
in  Fig.  57. 

§  1431.  Auris,  ear.— This,  the  organ  of  hearing  in  the  cat  as  in 
the  higher  animals  generally,  is  composed  of  three  parts,  two  of 
which  (labyrinth  and  tympannm)  are  completely  encased  in  bone. 

(A)  Auris  ectalis  (externa),  ectal  or  external  ear.— This  includes 
the  external  ear,  commonly  so  called,  which  is  partly  cartilaginous, 
and  the  meatus  auditorius  ectalis  (externus),  a  partly  bony  canal 


THE    EXTERNAL    EAR.  527 

leading  to  the  membrana  tympani.  Both  are  lined  witli  skin,  whicli 
extends  also  over  the  membrana  tympani. 

(B)  Tympanum  s.  Auris  media  (Fig.  127). — The  middle  ear  is  an 
elliptical  cavity  in  the  bone,  lined  with  mncous  membrane  and  con- 
taining the  bones  of  the  ear  and  their  muscles  and  the  chorda  tym- 
pani nerve.  Into  it  opens  the  Eustachian  canal  (Fig.  58,  88),  which 
puts  it  into  communication  with  the  pharynx. 

(C)  Labyrinthus  s,  Auris  entalis  (interna),  (Fig.  127). — The 
ental  (internal)  ear  or  labyrinth  is  the  sentient  portion  of  the  ear. 
It  consists  of  three  parts,  a  common  cavity  (vestibulum\  from  which 
extend  the  other  two— in  one  direction  the  canales  semicircular es^ 
in  the  other  the  cochlea.  In  the  living  body  the  cavity  of  the  inter- 
nal ear  is  closed  and  lined  with  a  thin  periosteal  membrane,  but  in 
the  macerated  skull  the  fenestra  rotunda  and  fenestra  ovalis  put  it 
into  communication  with  the  tympanum. 

Dissection. — Remove  the  head  of  a  3^oung  cat  and  wash  away 
the  blood. 

§  1432.  Auris  ectalis. — The  external  ear.  The  outer  prominent 
part  turns  its  concave  surface  latero-cephalad.  Note  its  flexibility 
and  elasticity,  also  the  little  pocket  on  its  lateral  border  (Fig.  87). 
Spread  the  edges  apart.  Note  the  numerous  ridges  and  winding 
ways,  and  that  it  is  only  partially  covered  by  conspicuous  hairs. 
At  its  latero-ectal  aspect  is  the  opening  into  the  Meatus  auditorius 
ectalis^  the  walls  of  which  are  firm  and,  near  its  termination,  bony. 

Remove  the  mandible,  os  hyoides,  tongue  and  larynx,  also  the 
skin  from  one  side,  including  the  external  ear.  Then  isolate  the 
facial  (7th)  nerve  as  it  emerges  from  the  Fm.  stylo-mastoideum  (Fig. 

57,  Fm.  stm.).  Partially  isolate  also  the  Eustachian  canal.  The 
opening  of  the  canal  will  be  exposed  as  shown  in  Fig.  88,  by  slitting  the 
soft  palate  lengthwise  and  turning  the  flaps  aside.  From  this  point 
the  canal  extends  cando-laterad  to  the  bony  Eustachian  tube  (Fig. 

58,  Cn.  Eu.).  Remove  from  around  the  bulla  (Fig.  57)  everything 
except  the  Eustachian  canal  and  the  facial  nerve.  Cut  the  carti- 
laginous part  of  the  meatus  where  it  joins  the  bony  part,  but  do 
not  allow  the  instrument  to  enter  the  latter. 

§  1433.  Membrana  tympani  (Fig.  127).— Place  the  head  in  a 
good  light  and  look  into  the  bony  ectal  meatus.  A  nearly  trans- 
parent membrane  will  be  seen,  the  Membrana  tympani.  It  sep- 
arates the  ectal  ear  from  the  tympanum.  Note  the  white  rod  (handle 
of  the  malleus)  extending  across  its  dorsal  third. 


528  AJVATOJIICAL    TECHNOLOGY. 

%  1434.  Tympanum  s.  Amis  media. — With  nippers  remove  tlio 
wall  of  the  mesal  chamber  of  the  tympanic  bulla  (Fig.  58),  and 
note  the  delicate  membrane  lining  it,  also  the  bony  septum  (Fig.  58, 
Spt.  tym.)  separating  this  chamber  from  the  tympanum  proper 
except  at  a  point  directly  ventrad  of  the  fenestra  rotunda,  where  it 
is  notched,  thus  forming  a  free  communication  between  the  two 
chambers  of  the  bulla  (Fig.  58).  Carefully  remove  the  septum  with 
nippers  and  use  the  scissors  for  cutting  its  lining  membrane,  so  that 
nothing  may  be  removed  by  inadvertence.  Holding  the  head  in 
the  hand,  allow  the  light  to  fall  upon  the  tympanum  from  various 
directions.  Note  the  attachment  of  the  membrana  tympani  to  a 
ring  of  bone  terminating  the  ectal  bony  meatus,  and  that  the  mem- 
brane is  conical  in  form,  the  apex  projecting  into  the  tympanum. 

§  1435.  Canalis  Eustachiana  (Fig.  5S,  88).  — This,  as  stated 
above  (Fig.  88),  is  the  canal  connecting  the  pharynx  and  tympa- 
num. Insert  a  beaded  bristle  into  the  pharyngeal  opening  (Fig.  88) 
and  it  will  appear  at  the  tympanic  opening  in  the  cephalic  part  of 
the  tympanum,  just  dorsad  of  a  projecting  shelf  of  bone. 

Ossicula  auditus,  Bones  of  the  Ear  (Fig.  127). — There  are  three 
of  these,  malleus,  incus  and  stapes,  extending  in  a  chain  from  the 
membrana  tympani  to  the  fenestra  ovalis. 

§  1436.  Malleus,  hammer  (Fig.  127).— The  malleus  is  the  first 
of  the  chain  of  ear  bones.  Its  handle  stretches  partly  across  the 
membrana  tympani.  With  the  tracer  move  the  handle  ;  it  will 
sway  but  little.  Note  that  the  neck  and  head  of  the  malleus  form 
an  angle  with  the  handle,  and  that  attached  to  a  small  cylindrical 
process  of  bone  arising  from  the  mesal  aspect  of  the  neck,  is  the 
short  tendon  of  the  tensor  tympani  muscle  (the  M.  EustacManus 
of  Straus-Durckheim,  A,  II,  200).  This  muscle  is  nearly  spherical 
and  occupies  a  concavity  slightly  cephalad  of  the  fenestra  ovalis. 
The  fossa  may  be  seen  on  a  prepared  skull.  With  scissors  cut  the 
tendon  of  the  muscle  and  then  the  dorsal  part  of  the  bony  ring  sup- 
porting the  membrana  tympani,  and  carefully  remove  the  malleus 
adhering  to  the  membrana.  Note  the  rounded  head  of  the  malleus 
and  also  the  long  flat  process  (processus  gracilis)  arising  from  the 
lateral  aspect  of  the  neck. 

§  1437.  Incus,  anvil  (Fig.  127). — This,  the  second  of  the  chain 
of  bones,  resembles  a  molar  tooth  with  two  divergent  fangs  rather 
than  an  anvil  (Quain,  A,  II,  631).  To  expose  it,  remove  the  cephalic 
part  of  the  tympanum  and  the  tensor  tympani  muscle.     Examine 


STAPES.  529 

under  a  strong  light  with  a  magnifier.  Note  the  larger  part  with  its 
concavity  for  articulation  with  the  malleus  and,  extending  ventro- 
mesad,  a  slender  process  which  articulates  with  the  stapes.  Con- 
tinue to  use  the  magnifier,  and  with  a  tracer  sever  the  connection 
with  the  stapes ;  then,  by  moving  the  incus  slightly,  it  will  be  seen 
to  occupy  the  caudal  part  of  an  elongated  fossa  caudo-laterad  of  the 
one  occupied  by  the  tensor  tympani  muscle.  The  shorter  j^rocess 
(fang)  is  held  in  position  by  a  ligament.  The  cephalic  part  of  the 
fossa  is  occupied  by  the  head  of  the  malleus.  Carefully  nip  away 
the  lateral  wall  of  the  tympanum  and  fully  expose  the  longer  pro- 
cess of  the  incus  and  its  ligament. 

§  1438.  Stapes,  stirrup  (Fig.  127).— This  is  the  third  and  last  of 
the  chain  of  bones.  (The  so  called  Os  lenticular e  between  the 
stapes  and  incus  belongs  properly  to  the  incus.)  The  narrow  part 
of  the  stapes,  termed  the  head,  articulates  with  the  longer  process 
of  the  incus,  and  its  broader  part  or  base  is  inserted  into  the  foramen 
ovale.  With  the  tracer  or  forceps  move  the  bone  slightly  from  side 
to  side,  and  there  will  be  seen  passing  caudo-laterad  the  tendon  of 
the  M.  stapedius.  Remove  the  lateral  wall  of  the  tympanum,  the 
mastoid  process,  etc.,  around  the  Fm.  stm.  (Fig.  57),  and  the  muscle 
will  be  seen  to  originate  near  the  aquseductus  Fallopii  (§  506)  entad 
of  the  7th  nerve.  On  the  prepared  skull  the  space  occupied  by  the 
stapedius  may  be  seen  to  be  separated  from  the  fossa  occupied  by 
the  incus  by  a  septum  of  bone.  After  the  muscle  is  well  made  out, 
grasp  its  tendon  and  pull  gently.  The  stapes  will  be  drawn  out  of 
the  fenestra  ovalis.  Note  the  small  bony  process  on  the  caudal  side 
to  which  is  attached  the  stapedius  muscle. 

LABYRINTHUS  s.  AURIS  ENTALIS  (INTERNA).    (Fig.  127.) 

§  1439.  Fenestra  rotunda  s.  Fenestra  cocMece  ;  Fenestra  ova- 
lis s.  Fenestra  testibuli. — These  two  gateways  to  the  labyrinth  have 
already  been  exposed.  Note  the  membrane  covering  the  fenestra 
cochlese.  The  fenestra  vestibuli  was  closed  by  the  base  of  the 
stapes  and  its  connecting  soft  parts.  These  foramina  open  respect- 
ively on  the  summit  and  side  of  the  cylindrical  cochlear  eminence. 

§  1440.  Cochlea. — The  cochlea  is  situated  mainly  in  the  cylin- 
drical elevation  at  the  caudo-lateral  aspect  of  w^hich  is  found  the 
Fenestra  rotunda  s.  cochleae.  It  consists  obviously  of  the  tapering 
canals  (soalae)  separated  by  a  lamina  of  bone  (lamina  spiralis,  Fig. 
128).  These  scalse  are  coiled  about  a  central  piece  (modiolus),  some- 
34 


530  ANATOMICAL     TECHNOLOGY. 

thing  like  the  shell  of  a  snail.  The  large  end  of  the  canal  is  visible 
through  the  membrane  covering  the  Fenestra  rotunda,  and,  since  it 
faces  into  the  tympanic  cavity,  is  called  Scala  tympani.  The  other 
canal  opens  into  the  vestibule  and  is  called  the  Scala  vestihidi. 

To  demonstrate  the  parts  of  the  cochlea,  rest  the  head  on  the 
occiput,  and  with  a  watch-spring  saw  make  a  section  across  the 
cochlear  eminence  so  that  the  Fenestra  vestibuli  is  divided  in  half. 
If  a  watch-spring  saw  is  not  at  hand,  one  may  employ  the  nippers. 
Remove  the  fragments  made  by  the  saw  or  the  nippers  by  blowing 
with  the  blowpipe.  This  will  expose  the  vestibule,  a  cross  section 
of  the  cochlea  and  the  opening  of  the  scala  vestibuli.  The  appear- 
ance shown  in  Fig.  127  will  be  seen,  except  that  the  membranous 
part  of  the  septum  may  be  torn.  The  direction  of  the  cochlea 
beyond  the  vestibule  is  nearly  in  a  line,  connecting  the  centers  of 
the  foramen  jugulare  et  ovale  (Fig  57),  and  if  the  ventral  wall  of 
the  cochlear  eminence  be  removed  along  such  a  line,  the  cochlea 
will  be  exposed  and  a  clear  view  obtained  both  of  the  Lamina  spi- 
ralis and  the  Modiolus  or  center  piece  around  which  the  coils  are 
made. 

To  remove  the  ventral  wall  of  the  cochlear  eminence,  press  a 
blunt-pointed  scalpel  or  arthrotome  against  the  wall  of  tlie  scala 
tympani  and  x)ry  carefully.  Usually  it  will  come  off  without  the 
least  difficulty.  The  exposed  cochlea  will  look  like  a  cork-screw. 
It  should  be  remembered  that  in  addition  to  the  lamina  spiralis 
which  forms  a  partition  between  the  two  scalse,  there  will  appear  a 
complete  wall  of  bone  separating  the  different  whorls. 

In  the  center  of  the  modiolus  is  a  cavity  or  canal,  and  the  lamina 
spiralis  is  perforated  by  many  small  holes,  giving  the  appearance 
of  a  sieve,  and  under  the  tripod  it  is  seen  that  through  these  the 
branches  of  the  auditory  nerve  pass,  to  be  distributed  to  the  sentient 
part  of  the  cochlea. 

§  1441.  Canales  semicirculares  (Fig.  127).— There  are  three  of 
these,  each  forming  about  two  thirds  of  a  circle,  in  the  periotic  bone. 
They  are  related  somewhat  as  are  related  the  three  dimensions  of  a 
cube,  and  open  into  the  vestibule  in  pairs.  From  their  position, 
they  are  named  as  follows  in  man,  and  the  terminology  has  been 
retained  for  the  cat :  external^  superior  and  posterior.  The  exter- 
nal one  (horizontal)  is  nearly  in  a  dextro-sinistral  plane  and  sur- 
rounds a  small  fossa  nearly  caudad  of  the  fenestra  ovalis.  The 
superior  one  is  in  a  dorso-ventral  (vertical)  transverse  plane.     It  is 


CAN  ALES    SEMICIRCULARES.  531 

in  the  ridge  forming  tlie  caudal  boundary  of  the  Fossa  appendicu- 
laris  (Fig.  59,  Fs.  ap.). 

The  posterior  semicircular  canal  is  in  a  dorso-ventral  (vertical) 
longitudinal  plane,  just  laterad  of  the  Fm.  jgl.  (Fig.  6Q).  As  stated 
above,  tlie  canals  open  into  the  vestibule  in  pairs.  The  opening  of 
one  end  of  the  posterior  and  superior  canals  may  be  seen  by  look- 
ing into  the  vestibule.  The  two  other  openings  are  situated  near 
the  edge  of  the  fenestra  ovalis,  one  laterad  and  one  mesad  of  the 
opening  just  described.  The  mesal  one  is  the  common  opening  for 
the  posterior  and  external  canals,  while  the  lateral  one  is  for  the 
superior  and  external  canals.  These  three  openings  are  situated  in 
a  line  connecting  the  middle  of  the  Fm.  jugulare  and  of  the  fenestra 
ovalis  (Fig.  57,  Fm.  j..  Ft.  ov.). 

To  trace  these  canals,  remove  the  perioticum  from  the  rest  of 
the  skull,  and,  commencing  at  the  central  or  common  opening  of 
the  posterior  and  superior  canals,  with  the  nippers  and  arthrotome 
carefully  remove  the  bony  walls  of  the  canal.  To  demonstrate  all 
the  canals  and  their  openings,  one  should  take  a  skull,  cleaned  pref- 
erably by  maceration  (§  250),  and  after  separating  the  perioticum 
from  the  rest  of  the  skull,  remove  the  wall  from  the  middle  of  the 
length  of  the  various  canals  (§  1441),  to  expose  them ;  then  insert 
fine  bristles  in  both  directions.  In  this  way  the  three  openings  of 
the  canals  may  be  found,  and  the  ends  of  two  bristles  will  be  found 
projecting  from  each  opening. 

§  1442.  Aquaeductus  cochleae. — This  is  a  canal  through  the  perioticum  which  trans- 
mits a  vein  from  the  scala  tympani.  One  opening  of  the  canal  is  near  the  fenestra  rotunda 
and  the  other  is  just  caudad  of  the  Meatus  auditor ius  internus  (entalis).  It  may  be  readily 
demonstrated  by  inserting  a  bristle  into  the  scala  vestibular  opening.  It  is  mentioned  so 
that  it  may  not  be  mistaken  for  the  opening  of  a  semicircular  canal. 

For  a  sketch  of  the  development  of  the  eye  and  ear  in  the  pig,  see  Hunt,  D.,  1  ;  for 
the  external  ear  passages,  2  ;  and  for  the  development  of  the  middle  ear,  3. 

Figure  127  was  suggested  by  the  diagram  of  the  human  ear  given  in  Huxley  and  You- 
mans,  A,  195,  Fig.  82.  It  is  meant  to  represent  the  three  parts  of  the  ear  in  their  relative 
order.  The  first  division  or  auris  ectalis  is  removed,  except  the  bony  and  a  small  part  of 
the  cartilaginous  meatus. 

The  bones  of  the  ear  were  placed  as  nearly  as  possible  in  their  proper  position  and 
outlined  with  a  camera  lucida. 

Explanation  of  Fig.  127. — Aquaeductus  cochleae  (Aq.  chl.). — A  passage  through  the 
petrosum  for  a  vein  from  the  scala  tympani  (§  1442). 

Canalis  Eustachiana  (Cn.  Eu.). — The  Eustachian  canal  opening  into  the  cavity  of 
the  tympanum  or  middle  ear  (§  1435). 

Canalis  semicircularis  posterior  (P.). — This  canal  is  represented  in  its  whole  length 
and  its  opening  at  one  end  with  the  external  and  at  the  other  with  the  superior  canal. 


532 


ANA  TOMICA  L     TE  CHNOL  OGT, 


Fig.  127.— Diagram  of  the  Cat's  Right  Ea.r,  Ventral  View  ;   x  about  5. 


Canalis  semicircularis  superior  (S.). — Only  the  be^nning's  of  this  are  shown.  One 
of  them  commences  in  common  with  the  posterior  and  one  with  the  external  canal  (§  1441). 

Canalis  semicircularis  externa  (E.).  Only  the  beginnings  of  this  canal  are  shown, 
one  of  them  opening  with  the  superior  and  one  with  the  posterior  canal  (§  1441). 

Cochlea.— This  is  represented  as  unrolled  and  the  ventral  surface  removed  so  as  to 
expose  the  scalse  and  the  lamina  spiralis  (§  1440). 

Cutis,  the  skin. — It  is  continuous  over  the  meatus  and  becomes  very  thin  as  it  extends 
over  the  membrana  tympani  to  form  its  ectal  layer. 

Fenestra  rotunda  (Ft.  rt.)  s.  Fenestra  cochlea. — In  life  this  is  inclosed  by  a  mem- 
brane.    It  leads  into  the  scala  tympani  of  the  cochlea. 

Fenestra  ovalis  (Ft.  ov.)  s.  Fenestra  vestibuU. — This  is  the  passage  from  the  tympa- 
num to  the  vestibule.  In  life  it  is  covered  by  the  base  of  the  stapes  with  its  connecting 
soft  parts. 

Incus. — The  middle  bone  of  the  ear.     It  is  also  called  anvil  and  dens  molaris  (§  1437). 

Labyrinthus. — This  is  the  third  and  last  or  sentient  part  of  the  ear.  It  is  often  called 
internal  ear. 

Lamina  spiralis  (Lm.  spr.). — This  is  a  plate  of  bone  arising  from  the  modiolus  or  col- 
umn  of  the  cochlea,  and  with  its  membranous  continuation  divides  the  cavity  of  the  cochlea 
into  the  two  scalae  (Fig.  128). 

Ligamentum  incudis  (Lgt.  inc.). — The  ligament  holding  one  of  the  processes  of  the 
incus  to  the  wall  of  the  tympanum. 

Malleus. — The  first  of  the  small  bones  of  the  ear.  It  is  by  far  the  largest  of  the  three. 
It  gains  itg  name  from  its  resemblance  to  a  hammer.  Its  handle  stretches  partly  across 
the  Mb.  tympani. 

Meatus. — The  name  is  written  in  the  meatus  ectalis  or  passage  from  the  exterior  to 
the  membrana  tympani  (§  1432). 


TRANSECTION    OF    A     COIL     OF    THE    COCHLEA. 


533 


Membrana  (Mb.)  tympani. — The  membrane  is  somewhat  funnel-shaped  as  shown. 
It  is  composed  of  three  layers,  the  skin  or  cutis  (see  cutis),  a  fibrous  central  or  intermediate 
part  and  a  continuation  of  the  tympanic  mucosa.  The  latter  covers  the  handle  of  the 
malleus  and  helps  to  bind  it  to  the  tympanum,  and  is  only  partly  shown. 

M.  stapedius  (M.  stp.). — The  name  is  connected  with  the  bony  process  of  the  stapes  to 
which  the  muscle  is  attached  (§  1438). 

M.  tensor  tympani  (M.  t.  t.). — There  is  here  shown  the  bony  process  of  the  malleus 
to  which  the  tendon  of  this  muscle  is  attached  (§  1436). 

O.  lenticulare  (O.  Int.). — The  small,  nearly  cylindrical  bone  between  the  stapes  and 
incus  (§  1438). 

Petrosum  s.  perioticum. — The  dense  bone  containing  the  parts  of  the  labyrinth  (§  510). 
Scala  vestibuli  (Scl.  vst.). — The  chamber  of  the  cochlea  opening  into  the  vestibule. 
It  is  divided  into  two  chambers  by  the  membrane  of  Reissner  (Fig.  128). 

Scala  tympani  (Scl.  tym.). — This  chamber  of  the  cochlea  is  separated  from  the  tym- 
panum only  by  membrane. 

Stapes. — The  last  of  the  small  bones  of  the  ear.     Its  oval  base  fits  into  the  fenestra 
ovali?.     Near  its  small  end  is  a  bony  process,  to  which  is  attached  the  stapedius  muscle. 
Tympanum. — This  is  tlie  second  or  middle  chamber  of  the  ear  (§  1434). 
Vestibulum  (Vst.). — The  vestibule  is  the  common  chamber  of  the  labyrinth  :  from  it 
extend  the  semicircular  canals  and  the  scala  vestibuli  of  the  cochlea  (§  1431,  C). 

Explanation  of  Fig.  128. — Canalis  cochleae  (Cn. 
chl.). — A  division  partitioned  off  from  the  scala  vesti- 
buli by  the  membrane  of  Reissner.  It  is  separated 
from  the  scala  tympani  by  the  membrana  basilaris 
(Mb.  bs.). 

Lamina  spiralis  (Lm.  sprl.). — This  is  the  bony 
partition  between  the  two  scalae.  The  partition  is 
completed  by  the  membrana  basilaris  (Mb.  bs.).  It 
arises  from  the  modiolus  and  through  it  passes  the 
cochlear  nerve  (N.  chl.). 

Membrana  basilaris  (Mb.  bs.)  s.  lamina  spiralis 
membranacea. — This  with   the  osseous  spiral   lamina 
completes  the  separation  between  the  scalae. 
The  organ  of  Corti  is  on  the  side  of  this  membrane  toward  the  canalis  cochleae  ;  no 
attempt  is  made  to  indicate  it  here. 

Membrana  Reissneri  (Mb.  R.),  s.  lamina  dentiaulata,  s.  linibus  laminoe  spiralis. — This 
membrane  divides  the  scala  vestibuli  into  two  parts  the  carMlis  cochlecB  and  the  scala  ves- 
tibuli proper. 


Fig.  128. — Transection  of  a 
Coil  of  the  Cochlea.  (From 
Quain,  after  Henle.) 


APPENDIX. 


ADOPTION  OF    NEW  TERMS    BY   OTHERS  (§   1443) — NIPPERS   (§   1444) — DROPPING-BOTTLE 

OILER  (§  1445,  Fig.  129) — liquid  gelatin  (§  1446) — obtaining  alcohol  free  op 

TAX  (§  1447) — DRYING  JARS  QUICKLY  WITHOUT  HEAT  (§  1448) — SOLUBLE  BERLIN 
BLUE  (§  1449) — BLUE  GELATIN  FOR  INJECTIONS  (§  1450) — OBTAINING  FROGS  AND 
NECTURI  (§§  1451,  1452)— PITHING  FROGS  (§  1453,  Fig.  130)— MACROTOME  (§  1454) 
BRAINS  OF  LOWER  VERTEBRATES  (§  1455) — USE  OF  MICA  (§  1456). 

§  1443.  Acceptance  of  the  new  nomenclature. — The  terms  of  description  em- 
ployed in  the  present  work  have  been,  upon  the  whole,  commended  by  The  Medical 
Record  (May  13,  1882,  Feb.  10,  1883),  The  Medical  and  Surgical  Reporter  (March  24, 1883), 
Science  (May  11,  1883),  Nature  (May  24,  1883),  The  American  Naturalist  (July,  1883),  and 
by  other  medical  and  scientific  journals.  Meson  and  its  derivatives  mesal  and  mesad, 
ectal  and  ental,  lateral,  tranuction,  Tiemisection,  etc.,  occur  in  The  American  Journal  of 
Neurology  and  Psychiatry  (I,  46,  50, 55,  101-104),  and  The  Journal  of  Nervous  and  Mental 
Disease  (XI,  1-38),  and  are  employed  more  or  less  uniformly  by  our  colleague,  Prof.  J.  H. 
Comstock  (A,  B),  by  Langley  and  Sherrington  {1,  55),  Morton  and  Dana  (Med.  Record, 
July  8,  1882,  p.  5),  Murie  (Zoological  Transactions,  VIII,  183),  Sachs  (Neurologisches 
Centralblatt,  Dec.  15,  1885,  p.  549),  Seguin  (5,  22,  23,  32,  etc.),  Spitzka,  {21,  422,  477), 
and  T.  B.  Stowell  (2,  2).  Dorsal,  mntral,  lateral,  cephalic  and  caudal  are  now  commonly 
used,  and  their  adverbial  forms,  dorsad,  laterad,  etc.,  are  not  infrequent.  Cephalic  and 
caudal  are,  of  course,  objectionable  theoretically,  because  they  are  employed  for  the  desig- 
nation of  special  parts  as  well  as  of  general  body  regions.  But  as  long  as  medical  writers 
persist  in  using  anterior  and  posterior  for  mntral  and  dorsal,  the  comparative  anatomist 
cannot  employ  the  former  without  risk  of  misapprehension. 

The  following  is  a  recent  illustration  of  the  ambiguity  of  descriptive  terms  applicable 
to  the  human  body  alone.  The  writer  spoke  of  the  "  transverse  diameter"  of  the  uterus  ; 
fearing  that  this  might  be  interpreted  as  dextro-sinistral,  he  qualified  it  by  the  words 
"  antero-posterior  ;  "  but  this  might  mean  either  caiido -cephalic  or  dorso-ventral.  ^ 

The  revised  encephalic  nomenclature  has  met  with  unexpected  favor  from  working 
neurologists  like  Osborn  (1,  2),  Spitzka  (7),  and  Wright  (Standard  Natural  History,  III, 
pp.  27-35),  and  the  first  named  permits  us  to  say  that  he  has  found  "the  greatest  advan- 
tage from  the  use  of  the  brain  terminology  in  practical  work."  As  stated  in  the  senior 
author's  paper  {63 ,  326),  Prof.  T.  JefFery  Parker,  of  New  Zealand,  had  independently 
employed  KotXla  as  the  basis  for  ventricular  designations  (A  and  2),  and  one  of  his  terms, 
mesocmle,  is  simply  a  paronym  of  mesoccelia. 

§  1444  (§146.)  Nippers. — Besides  the  ordinary  surgical  bone  forceps,  there  are  the 
dental  "  wedge-cutters,"  which  closely  resemble  the  nippers,  but  are  highly  polished  and 
provided  with  a  spring  for  separating  the  handles  ;  they  cost  about  $3.25. 


APPENDIX. 


535 


B^M^Cjj-^pp^^ 


GLas3  tLL/fti> 


§  1445  (§  147).  Dropping-bottle  Oiler.— A  bottle  of  the  kind  shown  in  Fig.  129,  used 
largely  in  microscopic  work,  is  found  to  be  a  very  convenient  oiler.  The  glass  tube  is  pre- 
pared as  directed  for  glass  canulae  (§  340),  except 
that  its  large  end  is  slightly  flared  while  hot  by 
pressing  it  upon  some  blunt,  pointed  object. 
The  bulb  is  a  pure  rubber  nipple. 

t^  1446  (§  251,  A).  Liquid  Gelatin.  — The 
liquid  gelatin  referred  to  is  prepared  as  follows: 
75  grams  of  the  best  translucent  glue  is  put  into 
a  clean  towel  and  crushed  with  a  hammer.  It 
is  then  placed  in  a  fruit  jar  and  100  cc.  of  com- 
mercial acetic  acid  poured  over  it.  After  stand- 
ing three  days  or  more  in  a  warm  place,  there 
should  be  added  100  cc.  of  water  and  100  cc.  of 
95  per  cent,  alcohol.  This  preparation  will  re- 
main liquid  at  the  ordinary  temperature  of  a 
sitting  room  (20°  C).  It  should  be  of  such  a  con- 
sistency that  when  spread  upon  ordinary  note 
paper  it  will  dry  on  the  surface  without  pene- 
trating the  paper.  If  too  thick,  it  may  be  thinned 
by  adding  the  liquids  in  the  proportion  given 
above,  or  it  may  be  thickened  by  adding  glue. 
This  liquid  glue  or  gels^tin  may  be  used  like 
common  mucilage.  Both  are  sometimes  im- 
proved by  mixing  them.  The  brush  used  must 
be  mounted  in  quill  or  something  that  will  not 
rust.  A  quill  duster,  with  the  addition  of  a 
wooden  handle,  answers  very  well. 

§  1447  (§  264).  Obtaining  Alcohol  Free  of 
Tax.— (A)  'The  original  bill  granted  the  privi- 
lege only  to  incorporated  or  chartered  institu- 
tions ;  later  provisions  apply  to  all  educational 
institutions. 

(B)  In  the  application  and  the  bond,  the  first  name  of  each  person  named  must  be 
written  in  full  or  an  unmistakable  abbreviation  must  be  given. 

(C)  The  bond  must  be  executed  for  a  sum  equal  to  double  the  amount  of  tax  due  upon 
the  alcohol  withdrawn. 

§  1448  (§  333,  A).  To  Dry  Jars  Quickly  without  Heat.— Clean  them  properly,  rinse 
them  with  rain  (or  distilled)  water,  and  let  this  drain  off.  Then  rinse  with  strong  alcohol 
^nd  finally  with  ether.  The  evaporation  of  the  latter  will  leave  the  surface  perfectly  dry. 
Recommended  by  F.  Lenggenhager  in  the  Druggists'  and  Chemists'  Circular. 

§  1449  (^  336).  Soluble  Berlin  Blue.— This  form  of  Berlin  blue  is  used  largely  in 
making  fine  injections  and  many  experiments.  Directions  for  preparing  it  are  given  in 
nearly  all  the  modern  works  on  Microscopy,  and,  being  so  widely  used,  it  has  become 
an  article  of  commerce,  and  may  be  had  of  most  dealers  in  microscopic  materials.  It 
should  be  obtained  in  the  solid  form  and  a  saturated  solution  prepared  with  distilled  or 
rain  water.  Such  a  solution  may  be  used  for  a  cold-flowing  injecting  mass  (§  1087),  or  it 
may  be  mixed  with  glue  as  directed  immediately  below. 

§  1450.  Blue  Gelatin  for  Injections.— To  prepare  this,  soak  fine  glue  in  clean  cold 
water  until  it  becomes  soft ;  then  transfer  it  to  a  metal  dish  and  heat  over  a  water  bath 


Fig.  129. — Dropping-Bottle  Oiler, 
WITH  Dropping  Tube  removed  ; 

X.5. 


53G 


APPENDIX. 


till  the  swollen  glue  melts.  Add  to  tliis  about  an  equal  volume  of  tlie  saturated  Berlin 
blue  (§  1449)  solution  heated  to  about  80  or  90  Centigrade.  Mix  thoroughly,  and  if  any 
dirt  is  present,  filter  through  fine  flannel.  The  solution  may  be  thinned  with  water.  It 
must  of  course  be  warmed  when  it  is  used,  and  the  animal  into  which  it  is  to  be  injected 
should  be  warmed  to  at  least  30°  C.  The  material  soon  becomes  moldy  in  warm  weather, 
so  only  about  the  amount  needed  should  be  made  at  a  given  time. 

Injections  with  colored  glue  are  made  precisely  as  directed  in  §  359.  After  the  injec- 
tion is  finished,  allow  cold  water  to  flow  upon  the  animal  or  set  it  away  in  a  cool  place. 

§  1451  (§§  1085,  1091).  Obtaining  Frogs  and  Menobranchi.— Notwithstanding  the 
abundance  of  frogs  in  certain  localities,  they  are  not  always  obtainable  when  wanted  for 
anatomical  and  physiological  purposes,  and  laboratories  should  keep  a  supply  on  hand. 

Boys  sometimes  capture  them,  but  are  apt  to  injure  them.  Large  frogs  may  some- 
times be  had  from  restaurants  or  from  large  dealers  in  fish  like  E.  G.  Blackford,  of  Fulton 
Market,  New  York  city.  Frogs  abound  in  the  marshes  near  Montezuma,  N.  Y,  and  may 
be  had  at  a  moderate  price  from  Mr.  Fennimore  Helmer  of  that  place. 

Frogs  may  be  transported  long  distances  in  a  box  of  wet  grass  if  a  few  airholes  are 
made.  They  should  be  kept  in  a  spring,  or  in  a  dark  covered  tank  or  vessel  through  which 
water  flows,  or  in  which  it  is  frequently  changed.  The  cover  is  needed  both  to  prevent 
their  escape  and  to  retard  their  vital  changes.  In  spite  of  care,  few  survive  more  than 
three  months  ;  the  larger  ones  often  die  within  as  many  weeks. 

§  1452.  Menobranchi  abound  in  the  lakes  of  central  New  York,  but  are  not  easily  taken 
with  the  net  on  account  of  the  depth  of  the  water,  and  the  supply  from  that  source  is 

therefore  variable.  We  have  usually  been 
able  to  obtain  them  in  considerable  num- 
bers at  short  notice  from  Mr.  Russel  Dee, 
of  Harmar,  Ohio.  Menobranchi  cannot 
live  long  out  of  water,  and  the  water  should 
be  changed  often.  For  transportation,  not 
more  than  three  should  be  put  in  a  pail  of 
water,  and  they  should  be  shipped  very 
promptly.  They  may  be  kept  easily  in 
aquaria,  especially  if  a  shelter  is  provided 
under  which  they  can  screen  themselves 
from  the  light. 

Alcoholic  examples  of  the  above  named 
animals,  as  well  as  of  many  other  forms, 
domestic  and  foreign,  may  be  had  from 
the  Natural  History  Establishment  of  Prof. 
H.  A.  Ward,  at  Rochester,  N.  Y. 

§  1453  (§  1086).  Pithing  Frogs.— 
This  is  an  expeditious  and  approximately 
painless  way  of  killing  frogs  for  anatomical 
and  experimental  purposes.  The  frog  is  to 
be  grasped  as  shown  in  Fig.  130 — the  pol- 
lex  upon  the  middle  of  the  back,  the  me- 
dius,  annularis  and  minimus  across  the 
belly  so  that  their  tips  are  related  to  the 
right  arm  and  leg  as  represented,  and  the  index  upon  the  head.  In  this  way  the  most 
active  and  powerful  frog  may  be  held  securely,  but  the  grasp  may  be  aided  by  a  bit  of 


Fig.  130. — Method  of  Holding  a  Frog 
FOR  Pithing. 


APPENDIX.  537 

cloth.  When  first  seized,  the  caudal  end  of  the  frog  should  be  held  downward  or  away 
from  the  ojjerator,  so  that  the  urine  may  not  be  discharged  upon  the  clothes. 

To  pith,  ventriduct  the  head  with  the  index,  and  pass  the  tip  of  the  right  index  from 
between  the  eyes  caudad  until  a  distinct  depression  is  felt  at  the  meson,  upon  a  line  corre- 
sponding nearly  with  the  caudal  margins  of  the  membranae  tympanorum.  With  a 
sharp-pointed  Charriere  scalpel,  divide  the  skin  transversely  for  about  3  mm.,  and  then 
plunge  the  scalpel  deeper  so  as  to  divide  the  "  medulla."  Respiratory  movements  cease, 
and  the  frog  is  supposed  to  be  dead  and  incapable  'of  feeling. 

If  the  cephalic  portions  of  the  brain  are  wanted,  the  head  should  be  cut  off  and  the 
brain  exposed  without  delay  (§  1087) ;  or  reflex  movements  of  the  limbs  should  be  pre- 
vented by  breaking  up  the  myelon  with  the  probe  or  a  piece  of  wire  introduced  from  the 
incision  into  the  neural  canal. 

§  1454  (§  1115).  Macrotome. — This  name  is  applied  to  a  simple  apparatus  upon  which 
sections  of  the  head  or  other  parts  may  be  made  with  a  saw.  It  is,  in  effect,  a  kind  of 
"  miter-box,"  and  is  made  as  follows  : — 

A  block  of  hard  wood  (ash,  oak,  etc.),  6  cm.  thick  and  about  18  cm.  long,  has  a  rebate 
("  rabbet  ")  cut  out  along  one  of  its  long  corners  to  a  depth  of  12  mm.,  and  is  then  accu- 
rately divided  at  about  the  middle  of  its  length. 

The  pieces  are  then  to  be  screwed  securely  across  a  perfectly  level  board,  about  36  x  18 
cm.,  at  about  10  cm.  from  one  end.  The  pieces  are  to  be  separated  by  only  the  thickness 
of  the  blade  of  the  small  back  saw  (§  152)  used  in  making  the  sections,  and  the  rebate  is 
to  be  above,  toward  the  shorter  portion  of  the  board. 

At  the  right  of  the  division  between  the  blocks  (or  at  the  left  if  the  operator  is  left- 
handed)  is  to  be  placed  a  block  about  4  cm.  thick  ;  it  is  to  be  adjustable  by  means  of  a 
thumb-screw  passing  through  a  slot.  In  §  1117,  this  block  is  called  the  slide  ;  in  some 
cases  it  may  be  dispensed  with. 

The  macrotome  may  be  used  not  only  for  hemisection  of  the  head,  but  also  for  making 
frozen  sections  of  limbs  and  other  parts.  The  saw  should  be  kept  sharp,  and  clean  but 
not  oily. 

§  1455  (§  1371).  The  Brains  of  the  Lower  Vertebrates.— The  brains  of  Amphibia 
and  of  the  air-breathing  Vertebrates  (Reptiles,  Birds  and  Mammals)  are  readily  compara- 
ble with  that  of  the  frog  or  Menobranchus.  But  those  of  the  "  fishes  "  (sharks,  skates, 
lamprey-eels,  Ceratodus,  gar-pikes  and  Teleosts)  have  not  yet  been  homologized  satis- 
factorily, and  the  beginner  is  not  advised  to  undertake  their  examination  ;  some  idea 
of  the  difficulties  may  be  gained  from  the  special  papers  by  various  writers  upon  the  brains 
of  the  several  groups  and  from  a  brief  summary  by  the  senior  author  (A?f>). 

§  1456  (§  318).  The  Use  of  Mica  for  Mounting  Alcoholic  Specimens.— Prof.  Leslie 
A.  Lee  has  kindly  called  our  attention  to  the  use  of  slips  of  mica  for  the  mounting  in  alco- 
hol of  preparations  which  require  some  support.  It  can  readily  be  cut  into  the  desired 
shape,  and  holes  can  be  drilled  through  which  may  be  passed  the  threads  for  supporting 
the  specimen. 

§  1457  (§§  1128,  1138,  1238).  The  Fornix.— According  to  an  editorial  in  the  Am.  Jour, 
of  Neurology  and  Psychiatry  (1,  402),  there  are  two  fornices,  right  and  left,  one  for  each 
hemisphere,  as  there  are  two  fimbrice,  etc.  This  commends  itself  to  us  upon  some  grounds, 
but  the  commonly  accepted  view  should  not  be  hastily  abandoned. 


BIBLIOGEAPHY 


In  the  following  Bibliography,  the  names  of  the  authors  are  arranged  alphabetically. 
The  looks  of  an  author  are  designated  by  heavy  letters,  and  the  papers  by  heavy  Arabic 
figures.  If  the  papers  are  recorded  in  the  Royal  Society's  Catalogue,  the  corresponding 
numbers  are  herein  given ;  otherwise  they  are  numbered  with  heavy  italicized 
figures  (§  3). 

The  more  common  book  sizes  are  indicated  by  the  initials  :  F.  (folio),  Q..  (quarto), 
O.  (octavo),  D.  (duodecimo). 

The  names  of  periodicals  are  abbreviated  as  in  the  Royal  Society's  Catalogue. 

The  Arabic  figures  in  ordinary  type  at  the  end  of  a  title  indicate  the  pages  in  the 
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Beale,  L.  S.  :  A. — How  to  work  with  the  microscope.  O.,  pp.  518,  100  plates,  5th  ed. 
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brate  heart,  with  physiological  remarks.     (1863.)    Phil.  Trans.,  1864,  pp.  445-500 316, 

Pye-Smith,  H.  :  1. — Suggestions  on  some  points  of  anatomical  nomenclature.  Jour, 
Anat.  and  Phys.,  XII,  pp.  154-175,  Oct.,  1877. . .  .14. 

Quain  :  A. — Elements  of  anatomy.  8th  edition.  Edited  by  W.  Sharpey,  Allen  Thomp 
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22,  94,  143,  152,  154,  157,  160-163,  166-167,  169,  172-174,  180,  184,  188,  192,  206,  212 
214-215,219,  221,  223,229,231,  235,  238,247,  250,  252,  254-260,  263,  265-272,  280-281 
283,285-287,  293-297,  302,  303-304,  307-308,  310-311,  316-317,  328,  331,  339,  342,  347, 
354,  361,  362-363,  372,  379,  382-387,  394-395,  399-400,  402,  404-406,  413-415,467,472-491 
507-509,  512-514,  520,  522,  526,  528. 

Ranvier,  L.  :  A. — Traite  technique  d'histologie.  O.,  pp.  976,  324  fig.  Paris,  1875- 
1882  (incomplete). . .  .399,  512. 

Reichert,  C.  B.  :  A. — Der  Bau  des  menschlichen  Gehirns.  Zweite  Abtheilung.  0.,  pp. 
192,  9  plates  and  10  fig.     Leipzig,  1861. . .  .405-406,  467. 

Roberts,  M.  J.  :  1. — Museums  as  educational  adjuncts  to  medical  colleges.  American 
Veterinary  Review,  June,  July  and  Aug.,  1882.  (This  paper  should  have  been  referred  to 
on  p.  136.) 

Robinson,  F.  E.  :  A. — A  table  of  the  cranial  nerves. . .  .510. 

Rolleston,  George  ;  A. — Forms  of  animal  life  ;  being  outlines  of  zoological  classifica- 
tion based  upon  anatomical  investigation  and  illustrated  by  descriptions  of  specimens  and 
figures.    O,  pp.  268,  12  plates.     Oxford,  1870. . .  .2,  57,  405. 

B.— The  Harveian  oration  for  1873.    D.,  pp.  90,  4  fig.    London,  1878 22,  316, 

330. 

13. — On  the  homologies  of  certain  muscles  connected  with  the  shoulder  joint. 

(1868.)     Linn.  Soc.  Trans.,  XXVI,  1870,  pp.  609-630. . .  .192. 

1. — Note  on  the  preservation  of  encephala  by  zinc  chlorid.     Jour.  Anat.  and 

Phys.,  XIII,  part  2,  pp.  232-233,  Jan.,  1879. . .  .435. 

Royal  Society's  Catalogue  of  Scientific  Papers  :  Compiled  and  published  by  the 
Hoyal  Society  of  London.     Q.,  1800-1873,  8  vols. . .  .3. 

Sabatier,  A.  :  A. — Etudes  surle  coeur  et  la  circulation  centrales  dans  la  serie  des  ver- 
tebres.     Montpelier,  1873. . .  .316. 

Sanderson,  J.  B.  (editor)  :  A.— Hand-book  for  the  physiological  laboratory.  O.,  text, 
pp.  585  ;  atlas,  123  plates.  Phila.,  1873.  Reprint  of  the  English  edition  with  slightly 
different  paging.     A  single  volume  edition  has  been  published  since 418. 

Sanders  :  i.— Contributions  to  the  anatomy  of  the  central  nervous  system  in  verte- 
brate animals.    London.     Pp.  44,  8  plates. . .  .24. 

Schobl,  J.  :  lO.— Ueber  die  Nervendigung  an  den  Tasthaaren  der  Saugethiere  so  wie 
liber  die  feinere  Structur  derselben.  Prag,  Abhandl,  V,  1872.  Archiv  mikrosk.  Anat., 
IX,  1873,  pp.  197-219. . .  .512. 

Schofield  :  j?.— Taste  goblets  in  the  dog  and  cat.  Jour.  Anat.  and  Phys.,  April,  1876, 
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Sedgwick,  W.  T.  :  1. — The  functions  of  the  semilunar  valves  of  the  aorta.  N.  Y. 
Med.  Rec„  May  28, 1881 . . .  .326. 

Serres,  E.  R.  A. :  A.— Anatomie  comparee  du  cerveau  dans  les  quatre  classes  des  ani- 
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1873,  pp.  301-302,  3  fig. . .  .161. 

20. — The  pectoral  muscles  of  mammalia.     Amer.  Assoc.  Proc,  XXII,  1873,  pp. 

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652  BIBLIOGRAPHY. 

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6*. — A  partial  revision  of  the  nomenclature  of  the  brain.    (Same  as  No.  5.) 57. 

7. — On  the  crista  fornicis,  a  part  of  the  mammalian  brain  apparently  unob- 
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9. — A  partial  revision  of  anatomical  nomenclature,  with  especial  reference  to 

that  of  the  brain.  "  Science,"  II,  No.  38,  pp.  122-126 ;  No.  39,  pp.  138,  138  ;  Mar.  19  and 
26, 1881. . .  .11-13,  18,  25,  27,  37,  57,  405-407,  414,  472,  474, 477,  480-481,  483,  486-487,  489. 

10. — The  two  kinds  of  vivisection,  sentisection  and  calUsection.  Medical  Rec- 
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11. — How  to  obtain  the  brain  of  the  cat.    "  Science,"  II,  No.  41,  April  9,  1881, 

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12. — Criticism  of  Spitzka's  "Notes  on  the  anatomy  of  the  encephalon,  etc." 

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meeting  of  the  Amer.  Assoc.  Adv.  Sci.,  1879,  but  not  yet  published. . .  .21,  57,  474. 

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gross  anatomy.     Amer.  Phil.  Soc  Proc ,  XIX,  pp.  524-562,  4  plates.     Read  July  15,  1881  ; 

publ.  Dec,  1881 57-58,  405-406,  414,  461,  472,  474-477,  480-481,  483,  486-487,  489, 

493,  496,  498-500,  508,  534. 

15. — On  a  mesal  cusp  of  the  deciduous  mandibular  canine  of  the  domestic  cat 

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21. — Frozen  sections  of  the  cat  preserved  in  alcohol.      Read  at  the  Amer. 

Assoc,  Aug.,  1879....  131. 

22. — On  the  brains  of  Amia,  Lepidosteus,  Ad/penser  and  Polyodon.     Amer. 

Assoc.  Proc,  XXIV,  1874,  pp.  168-185,  2  plates. . .  .410. 

23. — An  apparatus  to  show  the  action  of  the  diaphragm  in  respiration.    Boston 

Soc.  Nat.  Hist.  Proc,  XX,  1870,  p.  50. . .  .310. 

;^4.— Note  on  the  ectal  ("  apparent ")  origin  of  the  N.  trigeminus  in  the  cat. 

Amer.  Jour.  Neurology  and  Psychiatry,  I. . .  .508. 

26. — On  the  brains  of  some  fish-like  vertebrates.     Amer.  Assoc.  Proc,  1876, 

pp.  3,  5  fig.... 537. 

Williams,  H.  S.  :  A. — The  bones,  ligaments  and  muscles  of  the  domestic  cat.  0.,  pp. 
86,  with  atlas  of  12  folio  plates.  Copies,  reduced  one  third,  of  the  outline  plates  in  Straus- 
Durckheim's  A.     The  text  is  an  explanatory  index.     New  York,  1875 14. 


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Williams,  H.  S.  :  1. — Comparison  of  the  muscles  of  the  chelonian  and  human  shouL 
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Williams,  T.  :  A.— Article  Kespiration  in  Todd's  Cyclopaedia  of  anatomy  (g.  v.). . .  .310. 

Witt,  G.  :  A.— Compendium  of  osteology  ;  appendix  on  preparation  of  bones.  Folio. 
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Wood,  J.  :  7.— On  human  muscular  variations  and  their  relation  to  comparative 
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'  9. — On  a  group  of  varieties  of  muscles  of  the  neck,  shoulder  and  chest,  with 

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Wyman,  Jeffries  :  34. — Anatomy  of  the  nervous  system  of  Bana  pipiens.  Smith- 
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Proc, XI,  1868,  pp.  246-278. . .  .92. 

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462. . .  174,  191. 

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In  addition  to  our  obligations  to  many  of  our  laboratory  students  for  useful  hints 
upon  various  points,  we  feel  especially  indebted  to  those  named  below,  who  have  at  our 
suggestion  investigated  special  parts  of  the  cat's  anatomy  for  their  graduating  Theses  : — 

Collins,  Homer,  class  of  '82  :  The  brachial  flexor  muscles  in  man,  lion  and  cat. 

Curtice,  F.  C,  class  of  '81  :  A  study  of  the  tracheal  region  of  the  cat. 

Dounce,  G.  A.,  class  of  '79 :  Comparative  myology  of  the  shoulder  of  man  and  the  cat. 

Hoag,  W.  I.,  class  of  '81 :  On  the  masseter  and  temporal  muscles  in  the  cat. 

Manierre,  C.  E.,  class  of  '80:  The  fourth  cranial  nerve  in  man  and  the  cat. 

Schenck,  H.  D.,  class  of  '82  :  The  distribution  of  the  nerves  to  the  muscles  of  the  eye 
in  the  cat. 

Smith,  Theobald,  class  of  '81  :  The  peritoneum  and  its  principal  blood  vessels  in 
the  cat. 

Young,  J.  H.  W.,  class  of  '79  :  Comparative  myology  of  the  arm  in  man  and  the  cat 


ADDITIONAL    BIBLIOGRAPHY. 

This  additional  list  includes  the  titles  of  not  only  those  books  and  papers  which  are 
named  in  the  revised  text,  but  also  of  some  which  are  not,  but  would  have  been  referred 
to  had  the  entire  work  been  reset. 

Allen,  H.  :— A  System  of  human  anatomy,  iiicluding  its  medical  and  surgical  rela- 
tions.    Q.,  pp.  812  ;  109  plates,  241  figures.     Phila.,  1885. 

2. — The  muscles  of  the  limbs  of  the  raccoon(  Procyon  lotor).    Phila.  Acad.  Nat 

Sci.,  Proc,  May,  1882 ;  115-144. 

Anderson,  J. :— Article  Nervous  System  {Gomp.  Anatomy).  Cyc.  anat.  and  phys.  III., 
601-626,  24  figures. 


553a  BIBLIOGRAPHY. 

Bell,  F.  Jeffrey  : — Comparative  Anatomy  and  Physiology.  D.,  pp.  555,  229  figs. 
Phila.,  1885. 

Browning,  W.  : — The  veins  of  the  brain.  O.,  pp.  79,  2  figures.  Brooklyn,  1884, 
(The  first  sixteen  pages  appeared  in  the  Annals  of  Anat.  and  Surg.,  Jan.  1884.) 

Broca,  P.  :  3. — Description  elementaire  des  circonvolutions  cerebrales  de  I'liomme 
d'apres  le  cerveau  schematique.  Rev.  d'Authrop.  Paris,  1883,  VI,  1-34,  193-210,  385-405, 
2  plates,  5  figures. 

Buck,  A.  H.  (editor) :  A. — A  reference  hand-book  of  the  medical  sciences.  Illus- 
trated (incomplete).     New  York,  1885,  1886. 

Burdach,  Karl  F.  : — Vom  Baue  und  Leben  des  Gehirns.  Leipzig.  Q.,  erster  Band 
pp.  283,  2  Taf.  1819  ;  zweiter  Band,  pp.  418,  7  Taf.,  1822  ;  dritter  Band,  pp.  595,  1  Taf. 
1826. 

Carus  : — Lehrbuch  der  vergleichenden  Anatomic.  2  vols.,  Q.  Leipzig,  1834.  (On 
PI.  XIX  is  a  poor  figure  of  the  base  of  the  cat's  brain.) 

Claus,  C.  : — Elementary  text-book  of  zoology,  Part  II.  (mollusca  to  man.)  Trans- 
lated by  A.  Sedgwick.     O.,  pp.  352  ;  215  figs.     Nevr  York,  1885. 

Clevenger,  S.  V.  :  4, — Cerebral  topography.  Jour,  of  Nervous  and  Mental  Disease. 
Oct.,  1879,  pp.  27,  3  figures. 

Dalton,  J.  C.  :  B. — Topographical  Anatomy  of  the  brain.  Q.,  3  vols.  Pp.  175  ;  48 
plates,  with  outline  duplicates  ;  7  figures.     Phila.,  1885. 

Doane,  A.  S.  : — Transl.  of  Meckel  {q.  «.). 

Edinger,  L.  : — Ueber  den  Bau  der  nervosen  Centralorgane.  O.,  pp.  138,  120  figs. 
Leipzig,  1885. 

Familiant,  Victoria  :  J.— Beitrage  zur  vergleichung  der  Hirnfurchen  bei  den  Carni- 
voren  und  den  Primaten  im  Anschluss  an  die  Untersachung  eines  Lowen-Gebirnes.  Mit- 
theilugen  der  Naturforschenden  Gesellschaft  in  Bern,  II.  1885.  Pp.  35,  2  plates.  1885. 
Abs.  by  Edinger.     Neur.  Cntlbl.  IV.  488-489,  Nov.  1,  1885. 

Flesch,  M.  :  1, — Die  untere  Halskriimmung  des  Riickenmarkes  der  Saugethiere. 
Arch,  fdr  Anat.  u.  Phys.     Anat.  Abth.,  1885,  102-109,  Taf.  VI. 

Flower,  W.  H.  : — Introduction  to  the  osteology  of  the  mammalia.  3d  ed.,  revised 
with  the  assistance  of  H.  Gadow.     London,  1886. 

Fol,  Hermann  :  J.  — Description  d'un  embryon  humain  de  cinq  millimetres  et  six  dixi- 
emes.     Recueil  zoolog.  Suisse  i,  357-402,  pi.  xvi-xx,  1884.     (Printed  June  17, 1884) 405. 

Gage,  S.  H.  :  11, — Observations  on  the  fat  cells  and  connective  tissue  corpuscles  of 
Necturus  {Mendbranchus).  Proceedings  of  the  American  Society  of  Microscopists.  Vol. 
IV.  (1883),  pp.  109-126. 

/7. — The  application  of   photography  to  the  production  of   natural  history 

figures.     Science  III,  443-444,  2  fig.,  April  11,  1884. 

/.9. — A  starch  injection  mass.     New  York  Medical  Journal,  June  7,  1884.     (A 

slight  modification  of  this  is  interpolated  as  a  leaflet  between  pp.  140  and  141  of  this  edi- 
tion.) 

Ganser,  S.  :  3, — Ueber  die  vordere  Hirncommissur  der  Saugethiere.  Arch,  fiir  Psych., 
IX,  1878-9,  pp.  286-299, 1  plate. 

Gegenbaur,  C. :  D. — Lehrbuch  der  Anatoraie  des  Menschen.  Mit  558  zum  Theile  far- 
bigen  Holzschnitten.     Imp.  O.,  pp.  984,  558  figs.     Leipzig,  1883. 

Giacomini,  C.  :  3* — Fascia  dentata  du  grand  hippocampe  dans  le  cerveau  de 
I'homme.     Arch,  italiennes  de  biologie  V,  1-16,  PI.,  1-3,  396-417. 

Gray,  H.  : — Anatomy,  descriptive  and  surgical.  A  new  American  from  the  10th 
English  edition.     Imp.  6.,  pp.  1,023,  564  figs.     Phila.,  1883. 


BTBLIOGRAPHY.  5535 

Henle,  F.  G.  J.  : — Handbuch  der  systematischen  Anatomie  des  Menschen.  3  vols., 
0.,  pp.  2,724, 1,879  figs.     Braunschweig,  1871,  1873. 

Hess,  C.  :  1, — Das  Foramen  Magendie  und  die  Oeflfnungen  an  den  Recessus  laterales 
des  IV  Ventrikels.     Morpliolog.  Jahrb.,  X,  1885,  pp.  578-602.     Taf.  XXIX. 

Hoffmann,  C.  E.  E.  : — Lehrbuch  der  Anatomie  des  Menschen.  2d  ed.  fortgesetzt 
von  G.  Schwalbe.  0.  ,2  vol.,  pp.  1,804,  1.084  figs.  Erlangen  1877-1881.  (A  third  edition 
is  in  course  of  publication.) 

Hoffmann  u.  Schwalbe  : — Jahresberichte  ilber  die  Fortschritte  der  Anatomie  u.  Physi- 
ologie.     Leipzig. 

Howes,  G.  B.  :  A. — An  atlas  of  practical  elementary  biology.  Pp.  116,  figures,  etc., 
of  structures  described  in  Huxley  and  Martin  {q.  v.).     London,  1885. 

Huxley  and  Martin  : — Elementary  biology.  6th  revised  edition.  D.,  pp.  279.  London 
and  New  York,  1883. 

Hyrtl,  J.  : — Lehrbuch  der  Anatomie  des  Menschen.     18  Aufl,,  Imp.  O.,  Wien  1885. 

Kolliker,  A.  :  A. — Entwickelungsgeschichte  des  Menschen  und  der  hoheren  Thiere. 
O.,  pp.  1,033,  figs.  606,  2  Auflage.     Leipzig,  1879. 

B. — Grundriss  der  Entwickelungsgeschichte  des  Menschen  und  der  hoheren 

Thiere.      Fiir  Studirende  und  Aerzte.      2.  uragearbeitete  Auflage.     O.,  pp.  462,  300  figs. 
Leipzig,  1885. 

Langley,  J.  N.  :  1. — The  structure  of  the  dog's  brain.  Jour,  of  Physiology  IV.,  24&- 
285,  2  plates.     1883. 

Langley  (J.  N.)  and  Sherrington  (C.  S.) :  Jf.— Secondary  degeneration  of  nerve 
tracts  following  removal  of  the  cortex  of  the  cerebrum  in  the  dog.  Jour,  of  Physiol,,  V, 
49-65,  2  plates.     1884. 

Lewis,  W.  Bevan  : — The  human  brain,  histological  and  coarse  methods  of  research. 
O.,  pp.  163,  18  figs.     London,  1882. 

Macalister,  A.  : — An  introduction  to  the  systematic  zoology  and  morphology  of  verte- 
brate animals.     O. ,  pp.  365,  41  figs.     Dublin,  1878. 

Meckel,  J.  F.  : — Manual  of  general,  descriptive  and  pathological  anatomy.  Transl. 
from  the  French  [from  the  German]  by  A.  S.  Doane.     0.,  3  vols.,  pp.  1595.     Phila.,  1832 

Meynert,  T.  : — Psychiatry,  a  clinical  treatise  on  the  diseases  of  the  fore-brain  based 
upon  a  study  of  its  structure,  functions  and  nutrition.  Part  I.  The  anatomy,  physiology 
and  chemistry  of  the  brain.     Transl.  by  B.  Sachs.     O.,  pp.  285,  63  figs.     New  York,  1885. 

Morel  (Charles)  et  Mathias  Duval.  : — Manuel  de  I'anatomiste  (Anatomie  descriptive 
et  dissection).    O.,  pp.  1,152  469  figs.     Paris,  1883. 

Osborn,  H.  F.  :  1. — Preliminary  observations  upon  the  brain  of  AmpMuma.  Phila. 
Acad.  Nat.  Sci.  Proc,  1883,  177-186,  8  plates 400a. 

2. — Preliminary  observations  upon  the  brain  of  Menopoma  [Cryptobranch^is  Al- 

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5. — Observations  upon  the  amphibian  brain,  containing  results  of  microscopic 

study  upon  the  frog,  menobranchus  \^Necturus\,  menopoma  [Crpptobranclius]  and  amphi- 
uma.     Am.  Assoc.  Proc.  XXXIII,  522-523. 

4, — Development  of  the  brain.     Article  in  Buck's  Reference  Handbook  of  the 

Medical  Sciences,  I,  633-642,  51  figures.     New  York,  1885 400c. 

Parker,  T.  J.  :  A. — A  course  in  zootomy  :  Vertebrata.  Crown  0.,  pp.  XXIII,  397,  74 
figs.     London,  1884 400b. 

2, — Notes  on  the  anatomy  and  development  of  Scymnus  lichia.     New  Zealand 

Institute  Trans.,  1882,  XXV,  222-234,  2  plates.     Read  August  15,  1882;   issued  May, 
1883.... 400b. 


553c  BIBLIOGRAPHY. 

Quain :  A. — Elements  of  anatomy.  9tb  edition.  Edited  by  Allen  Thomson,  E.  A. 
Schiifer,  and  G.  D.  Thane.  2  vols.,  0.  pp.  1530, 1000  figs.  London  and  New  York,  1882 410. 

Rabl-Riickhard,  H.  :  2, — Das  Gehirn  der  Knochenfische.  Vortrag  gehalten  in  der 
Gesellschaft  fiir  Heilkunde  zu  Berlin  am  20,  Juni,  1884.  Biologisches  Centralblatt,  IV, 
499-510  (October  15,  1884),  528-541  (November  1,  1884),  with  10  figs. . .  .405. 

Sachs,  B.  : — Transl.  of  Meynert  {q.  v.). 

Sappey,  M.  P.  C.  : — Traite  d'Anatomie  descriptive.  3d  ed.,  rev.  O.,  4  vols,  pp.  3537 
2,413  figs.     Paris,  1877-79. 

Sedgwick,  A.  : — Transl.  of  Claus  {q.  v.). 

Spitzka,  E.  C.  :  IG, — Morphological  status  of  the  cerebellum.  N.  Y.  Medical 
Record,  July  26,  1884,  XXVI,  111. . .  .400c. 

20, — Hippocampus  vs.  Hypocampa.     N.  Y.  Medical  Record,  September  20,  1884, 

335 .. .  400b. 

21, — Contributions  to  the  anatomy  of  the  lemniscus,  with  remarks  on  centrip- 
etal conducting  tracts  in  the  brain.  N.  Y.  Med.  Record,  XXVI,  393-397,  421-427,  449- 
451,  477-481 ;  Oct.  11,  18,  25,  Nov.  1,  1884.     16  figs. 

23, — The  comparative  anatomy  of  the  pyramid  tract.     Journal  of  Comp.  Med. 

and  Surgery,  Jan.  1886,  pp.  47,  24  figs. 

24:, — Kurze  Notiz  die  Lumbal  Anschwellung  des  Riickenmarks  betreffend.  Neurol. 
Certlbl.,  IV,  481-482.     Nov.  1,  1885. 

Stowell,  T.  B.  :  2, — The  trigeminus  nerve  of  the  cat.     (In  preparation.) 

Weisse,  F.  D.  : — Practical  human  anatomy,  a  working  guide  for  students  of  medi- 
cine, etc.     Roy.  O.,  pp.  468,  321  figs.     New  York,  1886. 

Whitman,  C.  O. : — Methods  of  research  in  microscopical  anatomy  and  embryology. 
O.,  pp.  255,  36  figs.     Boston,  1885. 

Wiedersheim,  R. : — Lehrbuch  der  vergleichenden  Anatomic  der  Wirbelthiere  auf 
Grundlage  der  Entwickelungsgeschichte.     Large  O.,  2  vols.,  933  pp.  261  figs.     Jena,  1882. 

Wilder,  B.  G.  :  50, — Some  points  in  the  anatomy  of  the  human  brain.  Amer. 
Neurol.  Assoc.  Trans.,  1883.     Jour.  Nerv.  and  Ment.  Dis.,  N.  S.,  VIII,  1883,  pp.  85-86. 

51, — On  the  removal  and  preservation  of  the  human  brain.     Amer.  Neurol. 

Assoc.  Trans.,  1883.     Jour.  Nerv.  and  Ment.  Dis.,  N.  S.,  VIII,  1883,  pp.  81-82. 

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Neurol.  Assoc.  1883,  Amer.  Jour.  Neurol,  and  Psychiatry,  1883,  II,  pp.  491-499,  4  figs. 
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53, — On  the  alleged  homology  of  the  carnivoral  Fissura  cruciata  with  the  pri- 

matial  F.  centralis.  Amer.  Neurol.  Assoc.  Trans.,  1883.  Jour.  Nerv.  and  Ment.  Dis.,  N. 
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54:, — On  the  preparation  of    hollow  organs,  especially  the  brain  and  heart. 

Amer.  Soc.  Natural.,  1883.     (Unpublished.) 

53, — Methods  of  studying  the  brain.     The  "  Cartwright  Lectures"  for  1884. 

N.  Y.  Med.  Jour.,  XXXIX,  1884,  pp.  141-148,  177-183,  205-209,  233-237,  373-377,  457-461, 
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141-143,  197-199,  225-227,  365-367,  449,  450,  545,  546. . .  .400a,  400b,  400c,  410,  447. 

57, — On  encephalic  nomenclature.      Amer.  Neurol.  Assoc.  Trans.,  1884.  Jour. 

Nerv.  and  Ment.  Dis.,  1884,  pp.  18,  50  ;  abstract. 

58, — Do  the  cerebellum  and  the  oblongata  represent  two  encephalic  s-egments 

or  only  one  ?  Amer.  Assoc.  Proc.  XXXIII,  1884  Science,  IV,  1884,  p.  341  ;  N.  Y.  Med. 
Jour.,  XL,  1884,  p.  324. . .  .400c,  410. 


BIBLIOGRAPHY.  553<:? 

5.9.— On  some  points  in  anatomical  nomenclature.     Amer.  Assoc.  Proc,  XXXIII, 

1884, 

GO, — The    existence    and    dorsal    circumscription    of   the    porta    ("  Foramen 

Monroi")  in  the  adult  human  brain,  Amer.  Assoc.  Proc,  XXXIII,  1884;  N,  Y.  Med, 
Jour.,  XL>  1884,  p.  334. . 

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02. — The  use  of  slips  in  scientific  correspondence,     Amer.  Soc  Natural,,  1884. 

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(i.'i. — Encephalic  nomenclature.  1.  Coelian  terminology:  the  names  of  the  cav- 
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28,  1885,  8  figs. , .  ,400b,  400c,  410. 

f>4. — Paronymy  versus  heteronymy  as  neuronymic  principles.  Presidential  ad- 
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(i5, — On  a  seldom  described  artery  {A.  termatka)  with  suggestions  as  to  the 

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(id, — On  two  little  known  cerebral  fissures,  with  suggestions  as  to  fissural  and 

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6*ir. — Exhibition  of  preparations  illustrating  (A)  the  enlargement,  yet  complete 

circumscription,  of  the  porta  in  an  alinjected  hydrencephal  ;  (B)  the  continuity  of  the  dia- 
coelian  endyma  from  the  mesal  surface  of  the  thalamus  over  the  habena  to  the  diatele  ;  (C) 
the  insula  in  a  dog,  monkey,  chimpanzee  and  porpoise.  Amer.  Neurol.  Tians.,  1885. 
Jour.  Nerv.  and  Ment.  Disease,  XII,  July,  1885,  pp.  364-365. 

6*.9. — The  names  of  the  encephalic  arteries.     New  York  Medical  Journal,  Nov. 

28,  1885. 

71, — Educational   museums  of  vertebrates.      Vice-presidential  address  before 

the  Section  of  Biology.     Amer.  Assoc  Proc,  XXXIV,  263-281,  1885 

72, — On  the  use  of  alinjected  sheep  hearts  in  class  practicums.     Amer.  Soc 

Nat.,  Dec.  29,  1885. 

Wilder,  B.  G.  and  Gage,  S.  H. :  1, — The  zoological  and  histological  uses  of  Ncc- 
turus.    Amer,  Soc,  Natural.,  1883.     (Unpublished.) 

2, — On  the  use  of  vaseline  to  prevent  the  leakage  or  evaporation  of  alcohol 

from  specimen  jars.  Amer.  Assoc.  Proc,  1883,  XXXII,  p.  318.  N,  Y.  Med.  Jour. 
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3, — An  investigator's  table  with  double  or  triple  revolving  top,  and  movable 

book-rests.     Amer.  Soc.  Natural.,  1884.     (Unpublished.) 

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1, — On  the  nervous  system  and  sense  organs  of  Amiurus.    Canadian  Institute 

Proc,  N.  S.,  II,  353-386,  plates,  1,  4,  5,  6.  Read  January  12,  1884;  published  October, 
1884. 


INDEX 


In  the  following  Index,  technical  words  and  words  used  m  a  technical  sense  are 
accented  with  the  principal  accent.  In  this,  Webster's  Dicti)nary  has  been  followed 
whenever  possible.  There  is  also  herein  given  the  etymology  of  the  technical  terms  not 
found  in  the  last  edition  of  Webster's  Unabridged  Dictionary. 


Abbreviations  for  Parts  of   the   Brain, 

436-438. 
Abdo'men,  a  division  of  the  trunk,  36. 
ABDOM'INAL  and  thoracic  viscera,  lines  of 
incision  for  exposing,  274. 

blood  vessels,  355. 

transection,  how  to  do,  98-101. 

viscera,  273-297. 
Abdu'cens  nerve,  origin  and  distribution,  508. 
Absorbent  cotton,  62. 

ACCESSORY  or  spinal  accessory  nerve,  ori- 
gin and  distribution,  509. 

parotid  glands,  302. 
Accuracy,  limits  to  in  description,  27. 
Acous'tic  or  auditory  nerve,  origin  and  dis- 
tribution, 508. 
Actions  of  muscles,  202. 
Action  of  the  musdes  of  the  eye,  519. 
Ad'ipocere,  105. 

Adjective  and  adverbial  forms,  27. 
Adrena'le,  295. 
ADVERBIAL  and  adjective  forms,  27. 

ending,  27. 
Air  cells  of  lungs,  310. 
AL'BA,  functions  of,  371. 

structure  of,  398-399. 

white  nervous  matter,  369,  472. 
Al'bicans,  472. 
AL'COHOL,  a  perfect  preservative,  113. 

absolute.  112. 

admission  of  into  abdomen,  118. 

amount  required  for  different  purposes, 
121. 

anatomical  uses  of,  112-124. 

as  a  deodorizer,  83. 

care  of,  113. 

changing  the  percentage  of,  115-116. 

coagulation  of  tissues  by,  117. 

cost  of,  113. 

crystalline  deposits  in,  123. 

deterioration  of,  122. 


AL'COHOL,  determination  of  percentage  of, 
114. 
economics  of,  117. 
filtration  of  for  clearing,  122. 
filtration  of   for  deodorization  and  de- 
coloration, 123. 
how  to  obtain  free  of  tax  for  scientific 

purposes,  113,  535. 
inflammability  of,  114. 
injection  of  into  arteries,  119. 
injection  of  into  hollow  viscera,  119. 
injection  of  into  lungs,  119. 
injec  ion  of  into  thorax  and  abdomen, 

118. 
its  importance  and  general  character, 

112. 
measures   accessory  to   immersion    in, 

117-119. 
methyl,  or  wood  spirit,  124. 
percentage  of  required  for  brains,  etc., 

120. 
percentage  of   required  for  ligaments, 

etc.,  121. 
percentage    of   required  for  muscular 

organs,  120. 
precautions  against  fire  from,  114. 
purification  of,  122-123. 
reduction  of  with  water,  116. 
removing  from  hair,  131. 
settling  of  for  clearing,  122. 
special  characters  of,  113. 
specific  gravities  of  various  grades.  113. 
strengthening  of,  123. 
use  of  appropriate  grades  of,  117. 
vapor  as  a  preservative,  123. 
varieties  of,  112. 
Alcoholom'eter  (alcoSmeter),  114. 
Alcoom'eter  (alcoholometer),  114. 
Alisphe'noid  bone  {Latin,  ala,  a  wing,  and 
Greek,  acpr/v,  a  wedge,  eldoc  form),  181. 
Al'veolar  margin  of  the  jaw,  184. 


INDEX. 


555 


Al'veus,  lobulus  hypocampae,  481. 
American  Metric  Bureau,  5. 
Amphibia,  8. 

Amphibian  brain,  table  of  parts,  409. 
Amphiox'us  lanceola'tus,  10. 
AMPULLA  OF  VATER,  292. 

figure  of,  291. 
Anaesthet'ic  box  and  figure  of,  81. 
Analogies  and  difierences  of  vascular  and 

nervous  systems,  371-372. 
Anapoph'ysis  {nvu,  on,  and  (^velv,  to  grow  or 

be  produced),  172. 
ANATOM'ICAL     instruments    and    mate- 
rial, 59. 

Piiilistinism,  forms  of,  204. 
Angles  of  the  eyelids,  514. 
Angular  gy'rus,  501. 
An'gulus  mandibula'ris,  188. 
Animal  charcoal,  83. 

Animal  charcoal  for  filtration  of  alcohol,  123. 
An'nulus  abdomina'lis  exter'nus  and  inter'- 

nus,  297. 
ANTERIOR  fissure  of  the  spinal  cord,  478. 

perforated  space,  485. 

pillar  of  the  for'uix,  476. 
AOR'TA,  338. 

abdomina'lis,  358. 

abdomina'lis,  injection  of,  147. 

and  its  principal  thoracic  branches,  fig- 
ure of,  347. 

thorac'ica,  350. 
Apex  of  heart,  326. 
APHORISMS  for  dissectors,  197-198. 

general,  52-54. 

respectincr  nomenclature,  12. 
Aponeuro'sis,  an  undesirable  name,  196. 
Append 'ages  of  the  skin,  512. 
Appendic'ular  parts  of  the  body,  25. 
AQU^DUC'TUS  cochlea,  531. 

Syl'vii,  482. 
A'queous  humor  and  aqueous  chambers  of 

the  eye,  522. 
Arachuoi'dea,  413,  472. 
Ar'bor  vi'tae,  472. 
Arched  gy'ri,  500. 
AR'CUS  bicipita'lis,  245. 

neura'lis.  172. 
A'REA  crura' lis,  473. 

crura'lis,  diagram  of,  447, 

ellip'tica,  473. 

intercrura'lis,  473. 

ova' lis,  473. 

postponti'lis,  473. 

prsechiasma'tica,  473. 

septa'lis  of  brain,  473. 
Areas  and  lines  of  muscular  attachment,  195. 
Areom'eter,  114. 
ARM,  cephalic  or  anterior  limb,  29,  30. 

muscles  of,  with  figures,  225-271. 
Arrangement  of  cranial  nerves,  506. 
ARTE'RIA  adre'no-lumba'lis,  359. 

anastomo'tica  mag'na,  354. 

axilla' ris,  353. 


ARTE'RIA  brachia'lis,  353. 

bra'chio-cephaVica  s.  innomina'ta,  350. 

bronchia'lia,  351. 

cardi'aca,  326. 

carotidae'a,  figures  of,  345,  347,  392. 

carotidae' a,  injection  of,  148. 

circumflex'a,  353. 

circumflex'a  anterior,  353. 

coeli'aca,  358. 

co'lica  dex'tra,  359. 

co'lica  me'dia,  359. 

co'lica  sinistra,  360. 

corona'ria  ventric'uli,  359. 

cyst'ica,  358. 

epigas'trica,  361. 

femora'lis,  injection  of,  142. 

gas'tro  duodena'lis,  358. 

gas'tro-epiplo'ica  dex'tra,  358. 

hsemorrhoida'lis  supe'rior,  360. 

hepat'ica,  358. 

hypogas'trica,  361. 

il'eo  co'lica,  359. 

il'eo-lumba'lis,  360. 

ili'aca  exter'na,  361. 

ili'aca  intev'na,  361. 

intercosta'lis,  351. 

intercosta'lis  supe'rior,  351, 

interos'seus  ante'rior,  354. 

interos'seus  poste'rior,  354. 

lumba'lis,  351,  362. 

mesenter'ica  infe'rior,  360. 

raesenter'ica  supe'rior,  359. 

nu'triens,  354 

cesophagae'a,  351. 

ova'rii,  360. 

pancreat'ico-duodena'lis,  859. 

pancreat'ico-duodena'lis  inferior,  359. 

pericardi'aca,  351. 

phren'ica,  358. 

profun'da  supe'rior,  354. 

pulmona'lis,  326,  337. 

pylor'ica,  358. 

radia'lis,  354. 

radia'lis  recur' rens,  354. 

rena'lis,  360. 

sa'cra  me'dia,  361. 

spermat'ica,  360. 

splen'ica,  359. 

sterna'lis  s.  mamma'ria  inter'na,  351. 

subcla'via,  327. 

subcla'via,  branches  of,  351. 

subcla'via  dex'tra,  351. 

subcla'via  sinis'tra,  350. 

subscapula'ris,  353. 

suprascapula'ris,  352. 

thorac'ica  ante'rior,  352. 

thorac'ica  lon'ga,  352. 

ulna'ris,  354. 

ulna'ris  recur' rens,  354. 

ventric'uli  dorsa'lis,  359. 

vertebra'lis,  351. 

vesica'lis  supe'rior,  361. 
Ar'teries,  distinction  from  veins,  315. 


556 


INDEX, 


ARTERIES  of  the  thorax  and  arm,  350. 

of  the  trunk  and  arm,  34^3-344. 

structure  of,  363. 

to  inject,  143. 
AB'THRON  {uf)&pov,  a  joint),  166. 

capitel'li,  171. 

costicartilag'inis,  166. 

irio-sacra'le,  167. 

mesosterne'bri,  166. 

of  ribs,  165. 

tubsr'culi,  171. 
AR'THROTOME(upi?oi',  a  joint,  and  Te[xveiv, 
to  cut),  63. 

how  to  use,  201. 

figure  of,  68. 
Articula'tions  of  bones  of  skull,  176. 
Aspects  of  a  vertebrate,  figures  of,  30. 
Astrag'alus,  41. 
Atlan'tal  fora'men,  173. 
At'las,  171. 

Attachment  lines  and  areas,  195. 
Audi'tion,  hearing,  511,  53i). 
AU'DITORY  apparatus,  533. 

or  acous'tic  nerve,  origin  and  distribu- 
tion, 508. 
AU'LA  {Latin,  a  court-yard),  472. 

aud  por'ta,  407,  4o4. 

in  frog,  422. 
Auliplex'us  {Latin,  aula,  a  court-yard,  and 

plexus,  a  twining  or  braiding),  473. 
Au'ricles  of  heart,  section,   33^335,   Fig. 

93-96. 
AURICULA  dex'tra,  327. 

sinis'tra,  327,  338. 
Auricula'ris  mag'nus  nerve,  301. 
AU'RIS  {Latin,  th3  ear),  511,  538. 

bones  of,  528. 

enta'lis,  labyrinth' us,  529. 

me'dia,  523. 
Automat'ic  nervous  centers,  371. 
Ax'ial  part  of  body  (soma),  25. 
AX'IS,  171. 

band  or  cylinder  of  nerve,  399, 

coeli'aca,  35  S. 

thyroi'deus,  352. 
AZ'YGOUS  and  paired,  meaning  of,  33. 

lobe  of  the  lungs,  310. 

Ball  of  the  eye,  globus  oculi,  520, 
Band  axis  of  nerve,  399. 
Barnard,  F.  A.  P.,  5. 

BASE  of  brain,  figure  showing  segments  and 
nerve  roots,  443. 

of  the  heart,  327. 
Basilar  membrane  of  the  coch'lea,  533. 
Basioccip'ital  bone  (Latin,  basis,  the   base, 

and   occiput,    the    back    of  the  head), 

181. 
Basispbe'noid  bone  {i3aaic,  a  base  or  pedes- 

.tal,  a(t))jv,  a  wedge,  and  eldoc,  form),  181. 
Batrachians,  Amphibia,  8. 
Beaded  bristles,  63. 
Belly  or  body  of  a  muscle,  195. 


Benzine,  81. 

Berge,  J.  and  H.,  59. 

Bicip'ital  arch,  245. 

Bicus'pid  valves,  339-330. 

Bigem'inum  {Latin,  double,  twofold),  483. 

Blackford,  G.,  475. 

Bleaching  bjnes,  110. 

Bleeding  as  prelimmary  to  preservation,  117. 

Blind  spot  of  retina,  523. 

Blocks  for  dissecting,  G4. 

Blood- vascular  system,  315. 

Blood-vasciilar  system,  subdivisions  of,  315. 

BLOOD  VESSELS,  figure  of  general,  345. 

in  femoral  region,  figure  of,  143. 

isolating  and  drying,  346. 

met  bod  of   connecting   when  severed, 
511. 

of  the  trunk,  343. 

of  the  trunk,  figure  of,  345, 

structure  of,  302. 
Blow-pipe,  care  of,  74, 

figure  of,  66. 

flexible,  64. 
Blue  for  injections,  139,  535. 
BODY  cavities,  dor' sal  and  ven'tral,  33, 

figure  of  principal  divisions,  38. 

its  primary  divisions,  39. 

of  a  vertebra,  173. 

or  belly  of  a  muscle,  195. 

planes  of,  33 

planes,  figure  of,  34. 

table  of  principal  divisions,  39. 
Bone  nippers,  63,  67. 
Bone,  structure  of,  191. 
BONES,  bleaching  of,  110. 

cleaning  by  tbe  liquid  soap  process,  106. 

freeing  them  from  grease,  110. 

maceration  in  water,  105. 

of  limbs,  40. 

of  the  ear,  528. 

of  young  animals,  preparation  of,  109. 

preparation  of,  103. 

removing  soft  parts  from  alcoholic  spe- 
cimens, 105. 

soft  parts  removed  by  ants  or  Dermes- 
tes,  105. 
Borders  of  muscles,  designation  of,  197. 
Bottle  brush,  figure  of,  129. 
Box,  glass,  figure  of,  126. 
BRACHIAL  plex'us,  878-387. 

pi  ex' us,  figures  and  diagrams  of,  374, 
378.  381. 
Bra'chiura  pon'tis,  medipedunculus,  481. 
BRAIN,  abbreviations  of  names,  436-438. 

and  its  fissures,  494. 

and  myelon,  figure  of  dorsal  view,  374. 

cavities  completely  closed,  414. 

coe'lisD  or  cavities,  406. 

coe'liae,  exposed  from  ventral  side,  440. 

coe'lise,  figure  of,  ventral  exposure,  440. 

commissures  of,  439. 

com'iar!son  to  a  house,  413. 

definition  of,  400. 


INDEX, 


bb\ 


BRAIN,  exposure  of,  377,  435. 

exposure  by  removing  calva,  431. 

figure  of  the  base,  showing  segments, 
and  nerve  roots,  443. 

figure  of  the  mesal  aspect,  446-447. 

figure  showing  the  relations  of  the  cav, 
ities,  408. 

figure  of  a  transection  through  the  dia- 
coelia,  458. 

four  plates  of,  with  explanation,  461-471, 

general  considerations,  4C0. 

hardening  in  alcohol,  429. 

liardening  with  zinc  chlorid,  435. 

liemisection  of,  441. 

icl?al,  simple,  40S,  409. 

ideal,  simple,  diagrams  of,  408. 

importance  and  difficulty  of  its  study, 
400. 

injection  of  coeliae,  485. 

its  form,  493. 

killing  animal  for,  423. 

macroscopic  vocabulary  of,  436-438- 

mesal  aspect,  showing  segments,  etc., 
446-447. 

methods  of  study,  400. 

names  of  parts,  403-404. 

names,  synonyms  and  references,  alpha- 
betically considered,  471-491. 

of  Amphibia,  dissection  of,  420. 

of  Amphibia,  exposure  of,  3r7. 

of  Amphibia,  general  inspection,  418. 

of  Amphibia,  labelinpr,  418. 

of  Amphibia,  preservation,  418. 

of  Amphibia,  special  methods,  423. 

of  cat,  removal,  423. 

of  cat,  segmental  arrangement  of  names, 
446. 

of  cat  and  frog,  differences  of,  439. 

of  felines,  figures  by  various  authors, 
with  comments,  492-493. 

of  frog,  advantages  for  study,  402. 

of  frog,  exposure,  416. 

of  Menobranchus,  description  and  dis- 
section, 422. 

of  Menobranchus,  exposure,  417. 

of  young  human  subject,  method  of  re- 
moval, 432. 

plexuses,  injection  of,  436. 

removal  after  liemisection  of  the  head, 
432-433. 

segments,  404-406. 

segments,  examination  of,  450. 

segments  in  the  cat,  439. 

showing  dorsal  aspect  of  mesencepha- 
lon, etc.,  441. 

study  for  comparative  anatomist  and 
systematic  zoologist,  401. 

supporting  with  brine  while  removing, 
428. 

Table  of  parts  in  Amphibia,  409. 

transferring  to  alcohol,  419. 

ventricles  of,  coeliae,  406. 

weighing,  429. 


Brain,  weight  determined  from  capacity  of 

the  skull,  191. 
Brains,  etc. ,  percentage  of  alcohol  requirr^d 

for,  120. 
Breneman,  A.  A.,  123. 

Brevity  of  technical  terms,  importance  of,  15. 
Brine  for  supporting  brain,  125, 428. 
Bristles,  beaded,  63. 
Brou'chi.  311. 
Bron'chial  tubes,  311, 
Bronchio'li,  311. 
Brown,  F.  H.,  8. 
Bul'bus  for'nicis,  472. 
Bulla  tympan'ica,  185. 

Cae'cum  and  Ileo-caecal  Valve,  284-285. 
Calca'neum,  41. 

Cal'car  {Latin,  a  spur)  part  of  brain.  473. 
CALLO'SUM  {Latin,  hard,  firm),  439. 

corpus,  of  brain,  474. 

figure  of  its  dorsal  aspect,  442. 
Cam'era,  fornix,  479. 

CANA'LIS    bicipita'lis,    bicipital    arch    or 
groove,  158. 

centra'lis,  of  mye^on,  406,  474. 

cer'ebro-spina'lis,  370. 

coch'leae,  500. 

Eustachia'na,  185.  528. 

lachryma'lis.  179.  515. 

neura'lis.  172,  370. 

Schlem'mi,  523.  ( 

semicircula'ris,  530. 
Canalic'ulus  (Z,«^i?i,  diminutive  of  canalis,  a 

canal),  191. 
Canalic'uli  of  bone,  191. 
Can'thi  or  angles  of  the  eyelids,  514. 
CAN'ULA,  inserting  and  securing,  figure 
of,  145. 

introduction  into  vessels,  144. 

of  a  syringe,  character  and  i)reparation 
of,  138. 
CAPAClTf  of  organs,  determining,  135. 

of  skull,  determining,  191. 
CAPILLARIES,  general  character  of,  315. 

structure  of,  363. 
CAPITEL'LUM  {Latin,  diminutive  of  ca- 
put, a  head),  159. 

cos'tse,  166. 

hu'meri,  159. 
Cap'sula  len'tis,  523. 
CA'PUT  (Za^m,  a  head),  159. 

hu'meri  articula're,  159. 
Car'dia,  heart,  316. 
CAR'DIAC  arteries,  326. 

cavities,  323. 
CARE  of  instruments,  73. 

of  syringe,  137. 
Cari'na  for'nicis,  474. 
Carmine  solution  for  injection,  189. 
Carot'id  arterv,  injection  of,  148. 
CAR'PUS  and  tar'sus,  41. 

comparison  with  man,  41. 

of  lion  and  dog,  figure  of,  161. 


558 


INDEX, 


Cat,  advantages  fcr  study  as  compared  with 

the  dog,  rat,  rabbit,  etc.,  56. 
CATALOG  tJE,  data  for  specimen,  46. 

slip  box,  hgure  of,  50. 
CATALOGUES,  hbrary,  46. 

of  manufacturers,  59. 
Cau'da  stria' ti,  474. 
Cau'dal  and  cephal'ic,  use  of,  23. 
Cau'dal  or  tail  vertebra),  170. 
Caul,  omentum,  380. 
CAVITIES  of  the  body,  33. 

of  the  brain,  importance  and  advantage 

of  for  study,  401. 
of  the  brain,  communication  with  the 

exterior,  401. 
of  the  brain,  completely  closed,  414 
of  the  brain,  names  of,  406,  409. 
of  the  brain,  their  relation,  413. 
Ca'vum  o'ris,  303. 
Cel'la  {L'ltin,  a  cell),  me'dia,  474. 
Cements  for  bones  and  teeth,  107. 
Centigrade  thormometcr,  3. 
CENTRAL  canal  of  myelon,  413,  474. 
tubular  gray,  475. 
use  and  significance  of,  36. 
Cen'trum  vertebra'le,  172. 
Cephal'ic  and  cau'dal,  significance  and  use 

of,  23. 
CERE  BEL' LAR  cine'rea,  475. 

fos'sa,  186. 
CEREBEL'LUM,  474-475. 
lateral  lobe  of,  431. 
of  frog,  419. 
CER'EBRAL  fos'sa,  186. 

pedun'cles,  476. 
Cer'ebro-spi'nal  nervous  system,  309,  373. 
CER'EBRUM  and  its  fissures,  493-503. 
its  form,  493. 
parvum,  474. 
prosencephalon,  485. 
CERVICAL  nerves,  373. 

vertebrae  and  determination  of,  170, 
Cer'vico-fa'cial  division  of  the  facial  nerve, 

301. 
Cer'vix  of  a  rib,  166. 
Chain  hooks,  65. 

Changes  in  terminologv,  objects  and  meth- 
ods, 13. 
Charcoal,  animal,  for  filtering  alcohol,  etc.. 

83,  133. 
Charriere  scalpel,  69. 
Chaussiere,  15. 
Chest,  thorax,  308. 
Chevron  bones,  171. 
Chias'ma  {x/.aafia,  the  mark  of  the  letter  x). 

475,  507. 
Chloral  hydrate  as  a  preservative,  124. 
Chloroforming  animals,  80. 
Choice  of  origin  and  insertion  of  a  muscle, 

195. 
Cholecyst'is  (joA^,  bile,   kvgtic,  a   cyst    or 

bladder),  377,  3S6,  289. 
Chor'da  spermat'ica,  143. 


Chor'da  spinalis,  373,  483. 
Chor'dae  tendin'ea?,  '627. 
Clio'roid  plex'us  of  lateral  ventricles,  485. 
Choroi'dea,  521. 
C'hyle  vessels,  364. 
CIL'IARY  muscle,  525. 
plicae  or  folds,  523. 
Cim'bia,  tractus  transversus  pedunculi,  475. 
CINE'REA  {Latin,  of  or  like  ashes),  gray 
nervous  matter,  369-370,  475. 
functions  of,  371. 
of  the  brain,  475. 
structure  of,  398-399. 
Clark,  C.  F.,  64. 
Class  Mammalia,  8. 
Classification  of  animals.  Table  of,  9. 
Cla'va  {Latin,  a  knotty  branch),  475. 
Clav'icle,  clavic'ula,  56. 
CLAVIC'ULA,  clav'icle,  56. 

determination  of  right  and  left,  150. 

of  cat,  figured,  1G3. 
Claw  points,  removal  of,  102. 
Claws  as  appendages  of  the  skin,  513. 
CLEANING  bones,  103-111. 

canula  and  syringe,  146. 
Cleanliness,  precautions  for,  81. 
Cleavage  of  muscles,  195. 
Cleaves,  Prof.  E.  C,  vi,  xxi. 
Clements,  Miss  G.  D.,  xxi,  461. 
Clipping  the  hair,  204. 
Coagulation  of  tissues  by  alcohol,  117. 
Coarse  injections  of  blood  vessels,  137-148. 
Coats  of  the  eye,  521-523. 
Coccyge'al  nerves,  373. 
COCH'LEA,  539. 

canal  of,  531. 

scalse  and  spiral  lamina  of,  529. 

transection  of  a  coil  of,  533. 
Codman  and  ShurtlefF,  70. 
CCE'LI^  {Koi'lia,  a  cavity),  ventricles  of  the 
brain,  403. 

relations  of,  413. 

ventral  exposure  of,  with  figure,  440. 
Cce'lum,  trunk  cavity,  37. 
Col'lum,  neck,  39,  307. 
Co' Ion,  385. 

Colors  for  injections,  139. 
COLUM'NA  dorsa'lis  (myel'onis),  475. 

for'nicis,  475. 

latera'lis  (myelonis),  476. 

poste'rior,  475. 

ventra'lis  (mvelonis),  476. 

vertebra'lis,  169-173. 
Colum'iia3  car'nese,  337. 
Columns  of  alba  in  the  myelon,  370. 
Combi  nation  of  words,  28. 
COMMISSU'RA  ante'rior,  praecommissara, 
484. 

for'nicis,  476. 

habena'rum,  476. 

mag'na,  callosum,  474. 

me'dia     s.     mol'lis.     medicommissura, 
481. 


INDEX, 


559 


Commissu'ra    poste'rior,     postcommissura, 

484. 
Com' tnissures  of  the  brain,  407,  439. 
Common  ventricular  cavity,  aula,  472-473. 
Compound  words,  connecting  vowel  in,  28. 
Compressor,  figure  of,  65. 
Couarial  tube,  415. 
Cona'rium  {kQvoc,  a  cone),  pineal  body,  420, 

439.  476. 
Conductive  action  of  nerves,  371. 
CON'DYLUS  mandibula'ris,  189. 

occipita'lis,  183. 
Conjuncti'va,  514. 
Connect,  definition  of  term,  197. 
Co'nus  arterio'sus,  337. 
Copperas  as  a  deodorizer,  83. 
Co'rium,  derma,  cutis  vera,  true  skin,  512. 
Corks  and  rubber  stoppers,  126. 
Cor'nea,  521. 
COR'NU  Ammo'nis,  hypo 3am pa,  480. 

ante'rius  ventric'uli  latera'lis,  praecor- 

nu,  484. 
me'dium    s.    descen'dens,     medicornu, 

481. 
poste'rius.  postcornu,  484. 
Cor'onal  suture,  183. 
COR'PUS  al'bicans,  472. 

bigem'inum  ante'rius,  optici,  482. 
bigem'inum  poste'rius,  postoptici,  484. 
callo'sum,  474. 
can'dicans,  albicans,  472. 
fimbria'tum,  fimbria,  478. 
genicula'tum  exter'num,  484. 
genicula'tura  inter'num,  484. 
mammilla' re,  albicans,  472. 
pinea'le,  conarium,  420,  439,  476. 
pituita'rium,  hypophysis,  480. 
pyramida'le,  pyramis,  485. 
stria'tum,  488. 

trapezoi'des,  trapezium,  490. 
vit'reum,  522. 
Corpus'cula  Paci'ni,  281. 
COR' TEX  {Latin,  a  rind),  440. 
cer'ebri,  440.  475. 
of  the  enceplialon,  476. 
Cor'ti,  position  of  the  organ  of,  533. 
Cos'ta,  rib,  167. 

Cos'tal  car'tilage,  costicartila'go,  107. 
COTTON,  absorbent,  62. 

filtration  of  alcohol  through,  122. 
COT'YLOID  bone,  168. 

fos'sa,  168. 
CRA'NIAL  fos'sffi,  186. 
NERVES.  371. 

comparison  with  spinal,  504. 
method  of  demonstration,  511. 
numbering,  505. 

physiological  arrangement,  with  Ta- 
ble, 506. 
Table  of  origin,  exit,  distribution  and 

functions,  510. 
Table  of  synonyms,  505, 
Cra'nium  and  face,  174. 


Crib'riform  plate  of  the  ethmoid,  188. 
CRIS'TA  {Latin,  &  crest)  deltoi'dea  hu'meri, 
deltoid  ridge,  159. 

for'nicis,  476. 

il'ii,  167. 

lambdoida'lis,  179. 

pectora'lis  hu'meii,  pectoral  ridge,  159. 

tempora'lis,  179. 
CRU'CIAL  FISSURE,  constant  and  variable 
characters,  498-499. 

its  homology  and  formation,  500-502. 
Cru'ral  area,  473. 
CRUS  ante'rius  medul'lsD  oblonga'tse,  476. 

cerebel'li     supe'rius,     praepedunculus, 
485. 

ce'rebri,  476. 

e  cerebel'lo  ad  medul'lam,  postpedun- 
culus,  466. 

for'nicis  ante'rius,  476. 

me'dium,  medipedunculus,  481. 

ol  facto' rium  s.  rhinenceph'ali,  476. 
Crys'talline  lens,  522. 
Cuboi'des,  41. 
Cu'neiforme,  41. 
Curtis,  Miss  I.  M.,  XX i. 
Cusps  of  deciduous  canines,  56,  188. 
Cu'ticle,  epidermis,  512. 
CU'TIS,  skin,  512. 

ve'ra,  derma,  true  skin,  512. 

DECAPITA'TION    of  a    Cat  for  the 
Brain,  423. 

of  a  frog  or  Menobranchus,  415. 
Decimal  systems,  3. 
Dee,  R,  536. 
Del'ta  for'nicis,  477. 
Del'toid  ridge  of  the  humerus,  159. 
Deo'dorizers,  83. 

Derivative  words,  formation  of,  28. 
Der'ma  {depfia,  the  skin),  cutis  vera,  true 

skin,  512. 
DESIGNATION   OF  organs,   organonomy, 
14. 

position  and    direction,  toponomv,   20, 
31 

the  cranial  nerves  by  numbers,  505. 
DETERMINATION  OF  muscular  homolo- 
gies, 196. 

right  and  left,  149. 

right  and  left  with  entire  limbs,  151. 

the  capacity  of  the  skull,  191. 
Deutenceph'alon  {(hvTEpor,  second,  h>,  with- 
in, KE(l>a'Xri,  the  head),  diencephalon,  477. 
Dex'tral  and  sinis'tral,  use  of,  24. 
Diacoe'lia  {fiid,  between,   kolILo.,  a  hollow), 

third  ventricle  of  brain,  477. 
Diagonals  of  solids,  designation  of,  35. 
Diagrams  of  ideal,  simple  brain,  408. 
DIAPHRAG'MA,  277,  281,  311. 

figure  of  caudal  or  peritoneal  surface, 
313. 

partition  between  thorax  and  abdomen, 
37. 


560 


INDEX. 


Diaphrapr'ma,  tendons  of,  311. 
Diapli'ysis  {did,  through   or  between,  and 
(i>vEi.v,   to  grow  or    be    produced), 
humeri,  shaft  of  a  bone,  158, 159. 
Diaplex'us  {^td,  through  or  betweeu,   and 

Latin  plexus,  a  twisting  or  braiding), 

plexus  of  third  ventricle,  422,  477. 
Diapoph'ysis  of  a  vertebra,  173. 
Diate'la  {616.,  through  or  between,  and  Latin 

tela,  a  web),  477. 
DIENCEPH'ALON  (6ui,  between,  iv,  with- 
in,  and  Ke(l>a'kr),  the  head),  477. 

examination,  452. 

in  Amphibia,  420. 
Differences  of  brain  of  cat  and  frog,  439. 
Direct  lines,  34-35. 

DIRECTION  AND  POSITION,  designation 
of,  20,  34. 

on  direct  lines,  35. 

on  oblique  lines,  35. 
Disarticulating  skulls,  109. 
Display  of  alcoholic  specimens,  129. 
DISSECTING  gown,  05. 

instruments,  how  to  use,  199-201. 
DISSECTION  a  fine  art,  193. 

of  muscles,  instruments  and  materials 
for,  198. 

of  muscles,  preparation  of  cat  for,  198. 

of  the  amphibian  brain,  420. 

of  the  heart,  336. 

of  the  brain,  450-457. 

wounds,  85. 
Dissections    by    beginners    should    not    be 

published  without  careful  examination, 

19]. 
DISSECTORS,  aphorisms  for,  197-198. 

practical  suggestions  for,  201-203. 
Dis'tal,  significance  and  use  of,  25. 
DISTINGUISHING  the  groups  of  vertebrae, 
170. 

vessels  from  nerves,  375. 
Dividers,  duplicating,  67. 
DIVISIONS  of  the  body,   figures  of,  30, 
38. 

of  a  muscle,  195. 

of  the  sensory  nerves,  506. 
DOR'SAL  and  ven'tral,  use  of,  24. 

or  thoracic  vertebrae,  and  determination, 
170. 

or  upper  eyelid,  514. 

primary  division  of  myelonal  nerves, 
373. 

primary  division  of  nerves,  demonstra- 
tion, 377. 
Dor'sim^son,  ven'trimoson,  25. 
Drawing  materials,  67. 
Drills,  67. 

Dropping-bottle  oiler,  figure  of,  535. 
Drowning  animals,  80. 
Drying  to  be  avoided  in  dissection,  203. 
DUCT  of  the  parotid  gland,  301. 

of  the  submaxillary  gland,  302. 
Dacts  of  salivary  glands,  preparation,  298. 


DUCTUS  arterio'sus,  328. 

choled'ochus  commu'nis,  287. 

cyst'icus,  287. 

hepat'ici,  287. 

lachryma'lis,  516. 

Santorini,  292. 

Stenonianus,  301. 

thorac'icus  dex'ter,  365. 

thorac'icus  in  sections  of  thorax,  342. 

thorac'icus  sinis'ter,  364. 

thorac'icus  sinis'ter,  figure  of,  366. 

Whartonianus.  302. 

Wirsungianus,  290. 
Duode'num,  283. 
DU'RA  (mater),  477. 

removal  from  myelon  and  brain,  379, 
428. 

EAR,  Auditory  Apparatus,  526-533. 

auris,  bones  of,  528. 

diagram  of,  532. 

ectal  or  external,  526. 

ental  (internal),  labyrinthus,  529, 

middle,  or  tympanum,  529. 

muscles  of,  528,  529. 

semicircular  canals,  tracing  of,  530. 
Ear-pocket,  56. 
ECTAL  (£/cr6f,  outside,  external),  27,  36. 

and  ental  and  their  derivatives,  36. 

and  ental,  significance  and  use,  27. 

muscles  of  neck  and  shoulder,  figure  of, 
211. 

or  external  ear,  526. 
Elimination  of  slips,  47. 
Em'bryos,  percentage   of  alcohol   required 

for,  120. 
Emery,  76. 
EMINEN'TIA  audito'ria,  477. 

lenticula'ris,  488. 

mag'na  cer'ebri,  490. 
ENCEPHAL'IC  cavities,  names  of,  406. 

segments,  404-40G. 

segments,  examination  of,  450. 

segments  in  the  cat,  439. 

segments,  unequal  value  of,  406. 
ENCEPH'ALON,  definition,  400. 

general  considerations,  400. 

vocabulary  of  parts,  436-438. 
Endocar'dium,  362. 
En'dyma  (evdvjua,   a    garment),   ependyma, 

413,  478. 
ENT'AL  {ePT6c,  within,  internal),  27.  36. 

and  ectal  and  their  derivatives,  30. 

and  ectal,  significance  and  use,  27. 
En'terotome,  70. 

Enumeration  of  parts  in  series,  42. 
EPENCEPH'ALON  (fTf,  upon,  ev,  within, 
Ke(l)a./irj,  the  head),  478. 

examination  of,  451. 
Epen'dyma,  endyma,  478. 
Epicce'iia  {ewi,  upon,  and  Koula,  a  hollow), 

fourth  ventricle,  478. 
Epicon'dylus    {t-i,    upon,  and    KovdvTiOc;,   a 


INDEX. 


561 


knob  or  head),  external  condyle  of  hu- 
merus, 160. 
Epider'mis,  cuticle,  513. 
Epip'loon,  278,  280. 

Epiixjdial'ia  {ettl,  upon,  -kovc,  a  foot),  41. 
EPITROCH'LEA  {ettI,  upon,  and  rpoxa'^ta, 
a  pulley),  158,  IGO. 

internal  condyle  of  humerns,  169. 
Epitroch'Iear  fora'meu,  160. 
Ergot,  hippocampus  minor,  calcar,  473. 
ERRORS    of  interpretation    in    dissection, 
194. 

of  manipulation  in  dissection,  193. 
Ether,  inflammability  of,  114. 
E'therizing  animals,  80. 
ECrSTACHIAN  canal,  185,  528. 

valve,  380. 
Examination  of  brain  segments,  450. 
Exhibition  and  storage  of  specimens,  125- 

126. 
EXPOSURE  OF  brain,  425. 

frog's  brain,  416. 

heart,  31D. 

the  salivary  j^lands  and  their  ducts,  299. 
EXTERNAL  abdominal  ring,  297. 

auditory  meatus,  184. 

condyle  of  the  humerus,  160. 
EYE,  action  of  muscles  of,  519. 

definition  and  situation,  514. 

frozen  sections  of,  523. 

hardening  in  alcohol  for  study,  521. 

images  foj-med  by,  520. 

muscles  of,  516. 

nerves  of,  520. 

oculus,  and  its  appendages,  514. 

of  cat,  dorso-ventral  section,  523. 

tunics  or  coats  of,  521. 
EYEBALL,  form  of,  520. 

how  to  obtain  of  cat,  ox  or  sheep,  520. 
Eyelashes,  absence  of  in  cat,  514. 
EYELID,  third,  action  of,  515. 

palpc'jra,  514. 

Face  and  Cranium,  39,  174. 

Fa'cial  nerve,  origin  and  distribution,  508. 

Fahrenheit's  thermometer,  3. 

Fallopian  tube,  relation  to  ovary  and  perito- 
neum, 296. 

Falx  {Latin,  a  sickle),  removal  of,  428. 

FAS'CIA,  196. 
denta'ta,  478. 

Fascic'uli  of  muscles,  272. 

Fasci'ola  {Latin,  a  small  bundle),  cine'ren, 
478. 

Fau'ces,  513. 

Feline  brains,  comments  on  figures  of,  401. 

Fellow  of  the  opposite  side,  platetrope,  lat- 
eral homologue,  32. 

FEM'ORAL  artery,  injection  of,  142. 
blood  vessels,  figure  of,  142. 
vessels,  injection  of,  142,  146. 

FE'MCJR,  40. 

determination  of  right  and  left,  151 

3G 


FENESTRA  {Latin,  a  window),  184. 

ova'lis,  184,  529. 

rotun'da,  184,  529. 
Fibril'lae  of  muscle,  272. 
Fi'bro-cartila'go-intervertebra'lis,  171. 
FIB' U  LA,  40. 

determination  of  right  and  left,  151. 
Fifth  ventricle,  pseudocoelia,  485. 
Filter,  earthenware,  123. 
Fim'bria,  478. 
Fim'brial  fissure,  497. 
Finder,  tracer,  72. 
Fire,  precautions  against,  114. 
Fishes,  injection  of,  141. 
FISSU'RA  ansa'ta,  478,  498. 

ante'rior,  498. 

Bichati,  rima,  487. 

callosa'lis,  497. 

crucia'ta,  its  constant  and  variable  char- 
acters, 498. 

crucia'ta,  its  homology  and  formation, 
499. 

crucia'ta,  the  name,  synonyms  with  au- 
thorities, 499. 

dorsilatera'lis  (myel'onis),  478. 

dorsimesa'Iis  (niyel'onis),  478. 

fim'bria),  497. 

hypocam'paD,  497. 

Sylviana,  408. 

Sylviana,  its  constancy  as  compared 
with  the  FF,  rhinalis  and  postrhi- 
nalis,  498. 

transver'sa  mag'na,  rima,  487. 

ventrilatera'lis  (myel'onis),  478. 

ventrimesa'lis,  478. 
FIS'SURES,  cerebral,  and  gyri,  study  of, 
494. 

comparison  with  those  of  man  and  other 
mammals,  502. 

figure  of  the  lateral  and  mesal  aspects, 
494. 

formation  of,  497. 

three  problems  connected  therewith,497. 

homology  with  those  of  man,  502. 

list  of  the  constant  ones  in  the  cat, 
495-496. 

of  the  cerebellum,  494. 

pattern  in  the  cat,  501. 

promising  lines  of  inquiry,  503. 

relation  to  ental  structures,  497. 

relative  depth,  and  method  of  determin- 
ing and  indicating  on  drawings, 
495. 

structural  relations,  with  list,  497. 

Table,  with  synonyms,  496. 
FISSU'RAL   PATTERN,  constant   charac- 
ters, 501. 

variable  characters,  502. 
Flers.  killing  with  benzine,  64,  80. 
FLEXIBLE  blow-pipe,  61. 

specimens,  how  to  preserve,  121. 
Floe' cuius,  of  the  cerebellum,  478. 
Fol3om.  52. 


562 


INDEX. 


Foltz,  42. 

FORA'MEN  atlantale,  173. 

cae'cum,  478. 

cona'rii,  479. 

condyla're,  183. 

epitrochlea're    s.    supracondyloi'deum, 
160. 

inf undib' uli,  479. 

jugula're,  183. 

lac'erum  medium,  183. 

Monroi,  porta,  483. 

neura'le,  172. 

obtarato'rium,  167. 

of  Magendie,  414. 

of  Monro,  porta,  407,  421. 

of  Winslow,  280. 

ova'le,  of  heart,  328, 

palati'nura  poste'rius,  180,  184 

spbe'no-palati'num,  180. 

sty'lo-mastoi'deum,  183. 

vertebrarteria'le,  171,  173. 
Foram'ina  of  skull,  Table  of,  190. 
FORCEPS,  care  of,  74. 

coarse  and  fine,  67. 

figure  of,  66. 

how  to  use,  201. 
Form  of  the  cerebrum,  493. 
Formation  of  fissures,  497. 
Forms  of  muscles,  196. 
For'nix  {Lutin,  an  arch),  479. 
FOS'SA  appendicula'ris,  180. 

C3e'c.i,  478. 

cotyloi'dea,  168. 

man  libula'ris,  184. 

olecrana'lis  hu'meri,  160. 

orbita'lis,  180. 

ova'lis,  328. 

radia'lis  hu'meri,  160. 

temporalis,  180. 

thyro  hya'lis,  184. 

ulna'ris  hu'meri,  160. 
Fos'sB  of  skull,  186. 
Fourth  ventricle,  metacoelia,  478. 
Frazer,  Persifor,  5. 
Fresh    specimens    in    alcohol    should    not 

touch  sides  of  jar,  121. 
Frog  and  Menobranchus,  killing  for  brain, 

415. 
FROa'S  BRAIN,  advantages  for  study,  402. 

exposure,  416. 
From  and  of,  usa  of  with  adverbs,  27. 
FRONTAL  bone,  181. 

oi'nus,  183. 
FROZEX  dissections,  132. 

sections,   method  of  making  and  pre- 
serving, 131. 

sections  of  the  eye,  523. 

sections  of  the  thorax,  333-342. 
FUNCTIONS  of  the  alba,  371. 

of  the  cinerea,  371. 
FUNICULUS  (Latin,  diminutive  of  funis, 
a  cord),  grac'ilis,  cla'va,  475. 

of  a  nerve,  308. 


Gaboriau,  53. 

Gall  bladder,  277.  286. 

Gan'glia.  369. 

GANGLION  csr'ebri  posti'cum,  490. 

cervica'le  supe'rius,  395. 

hemispher'icum,  479. 

infe'rius  of  vagus,  500. 

jugula're  of  vagus,  509. 

petro'sum  of  glossopbaryngeus,  509. 

serailuna're,  391,  396. 
Ganglion'ic  nervous  matter,  cinerea,  475. 
General  sensibility,  512. 
Ge'nu  {Latin,  a  knee),  of  the  caliosum,  479. 
German  technical  terms,  16. 
Giacomini's  method  of  hardening  the  brain, 

435. 
Girdle,  definition  of  term,  197. 
GLANDS,  sweat  and  sebaceous,  512. 

lachrvmal,  515. 
GLAN'DULA  {Latin,  a  gland)  Harderi,  515. 

lachryraa'lis,  515. 

Meibo'miana,  514. 

mesenter'ica,  280. 

mola'ris,  302. 

paro'tis,  301. 

pinea'iis,  conarium,  476. 

sublingua'lis,  302. 

subm axilla' ris,  302. 

zygomat'ica,  303. 
GLASS  dishes  and  boxes  for  specimens,  126. 

jars,  127,  128. 

jars,  cleaning,  128,  535. 
GLO'BUS  OC'ULI,  eveball,  520. 

form  of,  520. 

how  to  obtain  of  cat,  ox  or  slieep,  520. 
Glossopharynge'al    nerve,   origin,   relations 

and  distribution,  509. 
Glot'tis,  gustatory  structures  in,  513. 
Glycerin,  15  per  cent.,  bottle  for,  72.. 
Go^dnow  and  Wiglitman,  59. 
Gould,  John  Stanton,  72. 
Grades  of  alcohol,  use  of  appropriate,  117. 
Gram,  4. 
GRAY  matter  of  the  brain,  476. 

nerv^ous  matter,  cinerea,  475. 
Grease,  removal  from  bones,  110. 
Groups,  muscular,  194. 
Gudden,  475. 
Gullet,  oesophagus,  308. 
Gusta'tion,  taste,  gustatory  sensibility,  513. 
GY'RI  and  fissures,  study  of,  494. 

angular,  501. 

arched,  500. 

designation  of,  500-501. 

oper'ti,  480. 

Habe'na  (Latin,  a  thong,   that  by  which 

anything  is  held),  479. 
Haben'ula  [Latin,  a  small  thong),  habena, 

479. 
HAIR,  clipping  the,  204. 

disposal  of,  204. 

parting  for  incisions,  143, 204. 


INDEX. 


563 


Hair,  parts  from  which  absent,  512, 

Hairs,  tactile,  512. 

Haraerton,  Philip  Gilbert,  52. 

Harder's  tear  g-land,  515. 

Haversian  canals  of  bone,  191. 

Head,  figure  of  a  hemisection,  305. 

Hearing,  audition,  auditory  sensibility,  511, 

526. 
HEART  and  blood  vessels,  structure  of,  362. 

a'pex,  326. 

appendix,  auricular,  326. 

base  of,  327. 

cardia,  316-338. 

cavities  and  parts,  diagram  of,  323. 

designation  of  regions,  318. 

difference  between  right  and  left,  324. 

dissection  of,  336. 

dorsal  aspect,  figure  of,  317. 

exposure  of,  319. 

figures  of  sections,  333-336. 

form,  normal  position,  size,  318. 

general  description,  317. 

hardening  in  alcohol,  322. 

injection  with  alcohol,  321. 

injection  with  plaster,  316. 

in  sections  of  thorax,  339. 

location  of,  317. 

physiologically  double,  323. 

preservation  in  alcohol,  321. 

recognition  of  regions  of,  318. 

removal  of,  319. 

removal  of  blood  from,  321. 

separation  from  lungs,  320. 

septum  of,  329. 

structure  of  its  muscles,  362. 

Table  of  parts,  322. 

transection  of  auricles,  334. 

transection  of  ventricles,  336. 

ventricles  of,  332. 
Helmer,  F.,536. 
HEMICAR'DIA  dex'tra,  328. 

difference  between  right  and  left,  324. 
Hemicer'ebrum,  479. 
Hemisec'tion  (?///<,  half,  and  Latin,  secare,  to 

cut),  of  the  brain,  444. 
Hcmisep'tum  {iiixi,  half,  and  Latin,  septum, 

a  partition),  cer'ebri,  479. 
Hemisphae'rse,  475,  479,  485. 
Hem'ispheres  of  frog's  brain,  420. 
He'par,  liver,  277,  286. 
Hepat'ic  ducts,  287. 
Hi'lum  of  kidney,  294. 

Hippocamp,  Eng.  paronym  of  Mppoeampns. 
HIPPOCAM'PUS,  lTCTz6KafxTvo^,  a  kind  of  fish, 
480. 

dissection,  exposure,  etc.,  453. 
Hippocam'pal  fissure,  497. 
HIPPOCAM'PUS  major,  480. 

minor,  calcar,  473. 
Holding  scalpel,  figures  of  ways  of,  199,  200. 
Hollow  viscera,  preparation  of,  132. 
HOMOL'OGIES,  intermembral,  42. 

muscular,  determination  of,  196. 


Homol'ogy  of  the  cerebral  fissures  of    cat 

and  man,  502. 
H3ne,  coarse  and  fine,  76 
Honing  and  stropping  instruments,  descrip- 
tion and  figure  of,  76. 
Horns  or  cornua  of  gray  matter  in  the  mye- 

lon,  370. 
Horns  of  the  uterus,  298. 
Human  subjects,  small,  55. 
HU'MERUS,  40,  157-161. 

determination  of  right  and  left,  150. 

figures  of,  156,  158,  228. 

figures  showing  muscular  attachments, 
228. 

general  description,  157. 

its  anatomical  head,  159. 

its  anatomical  neck  not  distinct  in  cat, 
159. 

its  ai-thral  or  anatomical  head,  159. 

its  diaphysis  or  shaft,  159. 

of  cat  does  not  appear  twisted,  158. 

special  mnemonics  of,  152. 
Hu'mor  a'queus  and  the  aqueous  chambers, 

522. 
Hybrid  words,  28. 
HYDROM'ETER,  British,  114. 

jar  for,  115.         specific  gravity,  114. 
Hypoglos'sal    nerve,   origin,   relations    and 

distribution,  509. 
HYPOPH'YSIS.   derivation   from   the    ali- 
mentary canal,  415. 

of  Amphibia,  423. 

pituitary  body,  480. 

Ideal,    Simple    Brain,    with    Diagrams, 
408-409. 

Il'eo  cae'cal  valve,  284. 

ireum,  283. 

ll'iac  crest,  167. 

ll'io-pectine'al  line  and  eminence,  169. 

IFio-sa'cral  arthron,  167. 

Ilium,  168. 

Images  formed  by  the  eye,  520. 

INCIS'lONS  for  injection,  figures  of,  143- 
144. 
for  thorax  and  abdomen,  274,  Fig.  76. 

INCISU'RA  hypocam'psB,  480. 
vertebra'lis,  173. 

Inconsistencies    of    nomenc^.ature    in    this 
book,  19. 

In'cus  {Latin,  an  anvil),  538. 

India  ink,  67. 

Inferior  articulating  process,  173. 

Inflation  of  hollow  viscera  with  air  or  alco- 
hol, 133-134. 

Inflection  of  technical  words,  27. 

Infraorbital  gland,  303. 

INFUNDIB'ULUM  {Latin,  a  tunnel  or  fun- 
nel),  of  frontal  sinus,  181. 
of  hypoi)hysis,  480. 

In'iruinal  ring,  143,  297. 

Inhib'itory  centers,  371. 

Injec'tion,  choice  of  specimen  for,  141. 


564 


INDEX. 


INJECTION,  coarse,  of  blood  vessels,  137- 
148. 

incision  in  vessels  for,  143. 

making  an,  145. 

masses,  139. 

of  abdominal  aorta,  147. 

of  brain  cavities  with  alcohol  or  plaster, 
435. 

of  carotid  artery,  14S. 

of  femoral  vein,  140. 

of  femoral  vessels,  142. 

of  heart  with  alcohol,  321. 

of  plexuses  of  brain,  436. 

of  postcava,  147. 

of  V.  jugularis  externa,  147. 

time  of  making,  141. 
Innom'inate  bone,  1G8. 
Innoraina'tum,  determination  of  right  and 

left,  150. 
Insertion  and  origin  of  muscles,  195. 
Instrument  cases,  74. 

IN'STRUMENTS  and  materials,  anatomi- 
cal, 59. 

and  materials   for   abdominal    transac- 
tion, 99. 

anl  materials  for  the  dissection  of  mus- 
cles, 198. 

dissecting,  how  to  use,  199. 

polishing  of,  75. 

sharpening  of,  76. 

valuj  of,  62. 
In'sula  (Latin,  an  island),  Reilii,  480. 
Integers,  muscular,  194. 
Interartic'ular  ligament  of  ribs,  165. 
In'terbrain,  diencephalon,  477. 
Intercru'ral  (Latin,  inter,  between,  and  cru- 

ralis,  belonging  to  legs),  or  interpedun- 
cular space  or  area  of  brain,  473. 
Intermediate,  use  of,  25. 
Intermem'bral  (Ljatin,   inter,  between,   and 

membrum,  a  member),  homologies,  42. 
INTERNAL  auditory  meatus,  181. 

condyle  of  humerus,  epi trochlea,  160. 
Interop'ticus    (Latin,    inter,  between,    and 

oTTTLKo^,  relating  to  sight),  480. 
Interpari'etal  (Latin,  inter,  between,  and  pa- 
ries, a  wall)  bone,  181. 
Intestines,  removing  to  avoid  odor,  84. 
INTESTFNUM  am'plum,  278,  285. 

te'nue,  278,  283. 
Intrinsic  toponomy,  23. 
Introduction  of  canula  into  vessel,  144. 
Iris  and  pupil,  520. 
Is'chium,  168. 
I'ter  (Latin,  a  way),  aqueduct  of  Sylvius,  480. 

JARS  for  Specimens,  figures  of,  127. 

and  bottles,  how  to  dry  quickly,  535. 
Jeju'num,  283. 
Ju'gular  vein,  injection  of,  147. 

KIDNEY,  Ren,  278,  294 

figures  of  sections,  293. 


KID'NEY,  relation  to  peritoneum,  279. 

relativ^e  position,  294. 

sections  of,  2t)8. 

structure,  294. 
KILLING  Amphibia,  415. 

animals  for  dissection,  79. 

cats  for  brain,  423. 

fleas  with  benzine,  80. 
Knots,  surgeon's  and  square,  figures  of,  144. 
Kolliker.  37. 
Kreider,  8. 

LA'BELING  Bones,  103. 

brains  of  Amphibia,  418. 
LabyrinTh'us(i/.'/^i«  and  Greek,  a  labyrinth), 

ental  or  internal  ear,  527. 
LACHRYMAL  apparatus,  515. 

bone,  181. 

canal,  179,  515. 

duct,  516. 

sac,  516. 
Lac'teals,  816,364 
Lacu'na?  of  bone,  191. 
LAMBDOID'AL  crest,  179. 

suture,  183. 
Lamel'la  ventra'lis,  172. 
LAMINA  cine'rea,  489. 

cribro'sa,  and  figure  of,  188. 

denticula'ta,  533. 

fus'ca  of  sclerotica,  521. 

neura'lis,  173. 

spira'lis  membrana'cea,  533. 

spira'lis  of  cochlea,  529-530. 

termina'lis,  489. 
Landmarks,  95-98. 
Larere  intestine,  278,  285. 
LATERAL  homologue,  platetrope,  32. 

ligament  of  urinary  bladder,  295. 

use  of,  24. 

ventricle,  485. 

white  column  of  the  spinal  cord,  476. 
Lead  chlorid,  83. 
Leakage  of  alcohol,  125. 
Lean  animals  better  for  dissection,  198. 
Lens  of  eye  and  its  ca[;Sule,  522-523. 
LIGAMENTS,    etc.,  percentage  of  alcohol 
required  for,  121. 

of  the  liver,  etc.,  formed  of  peritoneum, 
279. 
LIGAMEN'TUM  incu'dis,  123. 

interarticula're  cos'tae,  165. 

latera'le  of  the  urocystis,  295. 

Poupartii,  143,  Fig.  39. 

suspeuso'rium  of  lens,  523. 

susp/enso'rium  of  urocy'stis,  294. 

u'teri,  296. 
Ligatures,  144. 
LIMBS,  25,  29. 

bones  of,  40. 

designation  of  direction  and  relative  po- 
sition, 35. 

designation  of  regions,  25. 

normal  position  of,  37. 


INDEX, 


565 


Limbs,  se^rments  of,  40. 

Lim'bus  {Latin,  a  liem),  lamina  spiralis,  532. 

LI'MES  {Latin,  a  path),  480. 

al'ba  (of  rhiuenceplialon),  480. 

cine'rea,  480. 
LIMITS  of  accuracy  in  description,  27,  49. 

of  terminological  change,  18. 
LINES  and  areas  of  muscQiar  attachment, 
195. 

of  incision  for  exposing  the  thoracic  and 
abdominal  viscera,  274. 
Lin'gua,  tongue,  512. 
Liquid  soap,  106. 
Liq'uor  coelia'rum,  liquid  in  the  ventricles 

of  the  brain,  480. 
Liter,  4. 

Liver,  hepar,  277,  286. 
LOBES  of  the  liver,  286. 

of  lungs,  310. 
LOB'ULUS  appendicula'ris  cerebel'li,  480. 

cor'poris  stria'ti,  480. 

hypocam'psB,  481. 
LO'BUS  latera'lis  (cerebelli),  481. 

olfacto'rius,  in   frog  and  other   verte- 
brates, 420. 

olfacto'rius  not  a  nerve,  507. 

olfacto'rius,  olfactory  bulb,  481. 

op'ticus,  482. 

prosencephal'icus,  479. 

tempora'lis,  481. 
LO'CUS  perfora'tus  ante'rior,  485. 

perfora'tus  pos'ticus,  484. 
LUM'BAR  nerves,  372. 

vertebrae  and  determination  -of,  170. 
Luna're  (Latin,  Luna,  the  moon),  41. 
LUNGS  and  lobes  of,  310. 

and  tra'chea,  figure  of,  310. 

protection  of  in  removal,  320. 

separation  from  the  heart,  320. 
Lymph  vascular  system,  315-316. 
LYMPHAT'IC  glands,  316,  365-368. 

pflands,  injection  of,  367. 

vessels,  injection  of,  367. 
LYMPH AT'ICS,  316. 

comparison  with  veins,  316. 

of  the  arms  and  legs,  injection  of,  367. 

of  the  neck  and  face,  injection  of,  367. 

structure  of,  363. 
Ly'ra,  481. 

Macera'tion  of  Bones  in  Water,  105. 

Ma'cula  (Latin,  a  spot),  lutea  of  retina,  522. 

Magnifier,  tripod,  figure  of,  72. 

Malar  bone,  181. 

Malinverni,  474. 

Mal'leus  {Latin,  a  hammer),  528. 

Malo'dorous  parts,  84. 

Mammalia,  class,  8. 

Mammilla're,  albicans,  472. 

Mam'millary  process,  173. 

Man'dible,  lower  jaw,  figures  of,  188, 189. 

MANDIB'ULAR  condyle,  189. 

division  of  the  5th  nerve,  508, 510. 


Manuscript,  stops  in  tlie  preparation  of,  51. 
Mar' go  alveola'ris  of  the  jaw,  184. 
Matches,  care  of,  114. 

Mate' rials  and  instruments,  an&tomical,  59. 
MAX'ILLARY  bone,  181. 

division  of  the  5tli  nerve,  508,  510. 
MEA'TUS   {Latin,   a  passage),   audito'rius 
ecta'lis  (exter'nus),  184,  527. 

audito'rius  enta'lis  (inter'nus),  181,  509. 

ventralis  of  nose,  306,  513. 
Mediasti'num,  339. 

Medicomraissu'ra  (Latin,  mediun,  intermedi- 
ate, and  commissura,  a  joinings  togeth- 
er), 481. 
MEDICOR'NU  (Latin,  medius,  intermediate, 
and  cornu,  a  horn),  481. 

cornu  medium,  481. 

opening,  455. 

transection  of,  458. 
Medipedun'culus  (Latin,    medius,   interme- 
diate, and  pedunculus,  a  small   foot), 

481. 
MEDUL'LA  (oblongata),  400,  483. 

in  Amphibia,  419. 

spina'lis  (myelon\  482. 
Med'ullary  sheath,  369. 
Med'uUated  nerves,  398. 
Meibo'mian  glands,  514. 
Mem'bra,  limbs,  29. 
MEMBRA'NA  arachnoi'dea,  472. 

basila'ris,  of  cochlea,  533. 

nic'titans,  action  and  use,  515. 

Reissneri,  533. 

Sclmeideriana  of  nose,  513. 

tym'pani,  527,  533. 

vasculo'sa  cer'ebri,  483 
Me'ninx  vasculo'sa   {nyviy^,    a    membrane, 

and  Latin,  vasculum,  a  little  vessel), 

483. 
MENOBRANCHUS  and  frog,  killing,  415. 

brain  of  for  study,  403. 

distinguishing  male  and  female,  418. 

exposure  of  brain,  417. 
Mentol  symphysis,  189. 
MES'AL  (mes'al)  ;  {iieaoc,  middle),  24. 

aspect  of  the  brain,  showing  segments, 
etc.,  446,  447. 

incisions,  objections  to,  202. 

or  azygous  organs,  43. 

significance  and  use  of,  24. 
MESENCEPH'ALON  (/u'aor,  middle,  er,  in, 
and  Ke<t>a7.ri,  the  head),  481. 

figure  of  dorsal  aspect,  441. 

in  frog  and  Menobranchus,  419. 
Mesenteric  glands,  280. 
Mesente'rium,  mesentery,  278-279. 
Mesocoe'lia  (/neaog,  middle,  and  koiaIo,  cav- 
ity). 182. 
Meso-co'ion,  279. 

Mes'on  (mes'on);  {to  //eao?',themiddle\25,33. 
Mesopodial'ia  (/ieaof,  middle,  and   tzoi^,   a 

foot),  41. 
Mesorec'tum.  279. 


566 


INDEX. 


Mesostern'ebra  {fxtaog,  middle,  and  ortpvov, 

the  sternum),  167. 
Metacoe'lia  {/J-em,   after,   KotXta,  a  hollow), 

fourth  ventricle,  419,  483. 
Metaplex'us  (fierru,  after,  and  Latin,  plexus,  a 

twining  or  braiding),  483. 
MetapodiaV'ia  {fierd,  after,  ttov^,  a  foot),  41, 

43. 
Metapoph'ysis  (/leru,  after,  otto,  from,  and 

(pvetv,  to  grow),  173. 
Metate'la  {fierd,  after,  and  Latin  tela,  a  web), 

483. 
Metal  boxes  and  cans  for  specimens,  136. 
METENCEPH'ALON  {/xeru,  after,  tv,  with- 
in, and  KscpaATJ  the  head),  419,  483. 

examination  of,  450. 
METER,  4 

yard,  figure  of,  6. 
Methods,  importance  of,  53,  55. 
Meth'yl  alcohol,  134. 
METRIC  and  inch  measures,  figure  of,  0. 

and  other  measures  compared  and  re- 
duced, 7. 

and  other  systems,  comparison,  5. 
METRIC  SYS  rEM,  4. 

how  to  learn,  C. 

in  medicine,  8,  15. 
Midbrain,  mesencephalon,  481. 
MIDDLE  ear,  tympanum,  537. 

or  medi  ven'trlcle,  477. 

plane  (meson),  34,  33. 
Mitral  valves,  330. 
Mod'erator  band  of  heart,  330. 
Modi'olus  (Latin,  the  nave  of  a  wheel),  of 

the  cochlea,  539. 
Molar  gland,  303. 

MO' TOR  and  sensory  nerves  and  roots,  370, 
504. 

root  of  5th  nerve,  507-508. 
Mouth  cavity,  303. 

MUSCLES,  designation  of  the  borders  of, 
197. 

ectal  of  neck  and  shoulder,  figure  of, 
311. 

forms  of,  198. 

instruments  and  materials  for  the  dis- 
section of,  198. 

method  of  description,  306. 

names  of,  303. 

of  arm  and  scapula,  figures  of,  254,  363. 

of  ear,  538,  533. 

of  eye,  516. 

of  eye,  action,  519. 

of  eye,  nerve  sujjply,  530. 

of  eye,  origin,  519. 

of  left  shoulder,  figure  of,  346. 

of  neck  and  shoulder,  figure  of  second 
layer,  318. 

origin  and  insertion  of,  195. 

parts  of,  195. 

pectoral,  figure  of,  334. 

structure  of,  372. 

the  study  of,  Chap.  VI,  192-272. 


Muscles,  twisting  of,  197. 
MUSCULAR  fibers,  373. 

groups,  191. 

homologies,  determination  of,  196. 

integers  discussed,  194. 

organs,  percentage  of  alcohol  required 
for,  130. 

subdivisions,  195. 

variations,  193. 
MUS'CULUS,  definition  of,  194. 

acro'mio-deltoi'deus,  256. 

acro'mio-trape'zius,  314. 

bi'ceps,  366. 

brachia'lis,  367. 

choanoi'deus,  519. 

cilia'ris,  535. 

cla'vo-deltoi'deus,  331. 

cla'vo-mastoi'deus,  333. 

cla'vo-trape'zius,  315.  . 

coracoi'deus,  350. 

der'mo-humera'lis,  335. 

ec'tD-pectora'iis,  335-341. 

ec'to-tri'ceps,  363. 

cn'to-pectora'lis,  341-344. 

en'to-tri'ceps,  303-365. 

epitrochlea''ris,  359. 

exten'sor  (car' pi)  radia'lis  bre'vior,  369. 

exten'sor  (car'pi)  radia'lis  lon'gior,  368. 

exten'sor  (car'pi)  ulna'ris,  370. 

exten'sor  (di'giti)  min'imi,  370. 

exten'sor  (digito'ram)  commu'nis,  370. 

flex'or  (car'pi)  radia'lis,  371. 

indica'tor,  371. 

infraspina'tus,  357. 

latis'simus,  339. 

leva'tor  an'guli  scap'ulae,  250. 

leva' tor  clavic'ulae,  223. 

leva'tor  pal'pebrse,  518-519. 

meditri'ceps,  360. 

micosta'lis  s.  te'res  mi'nor,  358. 

obli'quus  dorsa'lis  (superior),  518-519. 

obli'quus  ventra'lis  (inferior),  517,  519. 

occip'ito-scapula'ris,  317. 

orbicula'ris  palpebra'rum,  516,  519. 

pec'to-antebrachia'lis,  336. 

platys'ma-myoi'des,  337. 

prona'tor  te'res,  371. 

pterygoi'deus.  535. 

rec'tus  dorsa'lis  (superior),  518-519. 

rectus  latera'lis  (externus),  517,  519. 

rec'tus  mesa'lis  (internus),  518-519. 

rec'tus  mi'nor,  519. 

rec'tus  poste'rior,  519. 

rec'tus  ventra'lis  (inferior),  519. 

rhomboi'deus,  319. 

serra'tus  raag'nus,  347. 

spi 'no-del toi'deus,  355. 

spi'no-trape'zius,  313. 

stape'dius,  539,  533. 

ster'no-mastoi'dens,  331. 

subscapula'ris,  353. 

supina'tor  lon'gus,  365. 

supraspina'tus,  354. 


INIfEXL 


567 


MUS'CULUS  suspen'sor  oc'uli,  519. 
ten'sor  tym'puni,  528,  533. 
te'res,  258. 
trochlea' ris  (dorsal  or  superior  oblique), 

518-519. 
xipli'i-huinera'lis,  244. 
Museum  catalogue  data,  46. 
Myelenceplial'ic  nervous  system,  369,  372 
My'elin  {pLvtlog,  marrow,  fat),  369,  398. 
MY'ELON  {uvtAoq,  marrow),  the  spinal  cord 
or  spinal  marrow,  19,  372,  483. 
in  Amphibia,  419. 
MYEL'ONAL  alba  and  cinerea,  370. 

nerves,  373. 
MYOL'OGrY,  general  considerations    upon, 
192-194. 
technical  terms  of,  194-197. 
the  study  of  the  muscles.   Chap.  VI, 
192-272. 

NAMES  and  Abbreviations  on  the  Fig- 
ures, 20. 
indicating-  relative  position,  17. 
of  brain,  segmental  arrangement  of,  446. 
of  muscles,  sourcas,  208. 
Na'sal  bone,  181. 
Na'sus,  nose,  513. 
Na'tis  cer'ebri,  opticus,  482. 
NATURAL  skeletons,  flexibla,  109. 

skeletons,  preparation  of,  108. 
Neck  (part  of  soma),  307. 
NERVE  cells,  399. 

fibers,  anastomoses,  399. 

roots  shown  in  figure  of  the  base  of  the 

brain,  443. 
supply  of  the  muscles  of  the  eye,  520. 
NERVES,  comparison  of  cranial  with  my- 
elonal,  504,  503. 
connection  with  the  limbs.  500. 
cranial,  general  considerations,  371,  501. 
cranial,  method  of  demonstration,  511. 
cranial,  numbering,  505. 
cranial,  physiological  arrangement,  with 

Table,  506. 
cranial,  Table  of  origin,  exit  and  func- 
tions, 510. 
cranial,  Table  of  the  synonyms,  505. 
distinguishing  from  vessels.  375. 
figure  of  a  transection  of  the  thorax, 
showing  the  relation  of  the  cerebro- 
spinal and  sympathic,  397. 
medullated,  398. 
motor  and  sensory,  370. 
non-medullated,  399. 
of  the  face,  301. 
subdivisions,  369. 
termination  of,  372. 
NERVOUS  and  vascular  systems,  analogies 
and  differences,  371-372. 
matter,  structure,  398,  399. 
plexuses,  370. 

system,  central  and  peripheral  portions, 
370. 


NERVOUS  system,  general  directions  for 

dissecting,  375. 

system,  primary  divisions,  369. 
NER'VUS  abdu'cens,  origin  and  distribu- 
tion, 482,  508. 

accesso'rius  (XI),  377,  389,  509. 

audito'rius,  origin  and  distribution,  508. 

auricula'ris  mag'nus,  301. 

circumflex' us,  385. 

cuta'neus  inter'nus,  384. 

facialis  and  audito'rius,  427. 

facia'lis,  origin  and  distribution,  508. 

gas'tricus  dorsa'lis,  391,  509. 

gas'tricus  ventra'lis,  390,  5G9. 

glos'so-pharynge'us  (IX),  389,  509. 

glos'so-pharynge'us,  va'gus  and  acces- 
so'rius, relations,  426,  509. 

hypoglos'sus  (XII),  389,  426,  509. 

interos'seus  poste'rior,  386. 

Lancisi,  488. 

larynge'us  recur'rens,  388,  3C0,  394,509. 

larynge'us  supe'rior,  509. 

maxilla' ris  supe'rior,  503. 

me'dius,  385. 

mus'culo-cata'neus  s.  cuta'neus  exter'- 
nus,  384. 

mus'culo-spira'lis,  886. 

oc'ulo-moto'rius,  507. 

oc'ulo-moto'rius,  trochlea'ris  and  abdu'- 
cens, relations,  427. 

ol facto' ri us  of  Amphibia,  420. 

olfacto'rius,  507. 

op'ticus,  507. 

phren'icus  s.  diaphragmat'icus,  383. 

pnea'mo  gas'tricus  (vagus),  387,  509. 

splanch'nicus,  395. 

subscapula'ris,  384. 

euprascapula'ris,  383. 

sympath'icus,  sympatheticus,  394. 

sympath'icus  in  the  abdomen  and  tail, 
396. 

thorac'icus  ante'rior,  382. 

thorac'icus  poste'rior,  or  external  respi- 
ratory of  Bell,  387. 

trigem'inus,  and  its  three  divisions  (1st 
or  ophthalmic,  2d  or  maxilla'ris,  8d 
or  mandibula'ris\  508. 

trigem'inus,  its  ganglion  (Gng.  Gasseri), 
508. 

trigem'inus,  its  motor  root,  origin  and 
distribution,  507-508. 

trigem'inus,  sensory  root,  origin,  508. 

trochlea'ris,  507. 

ulna'ris,  386. 

va'gns,  dissection  of,  388. 

va'gns,  Tsnoumogastricus,  origin,  distri- 
bution and  relations,  387,  388,  509- 
510. 
NEU'RAL  and  visceral  cavities,  33. 

arch,  172. 

canal,  172. 

fora'men,  173. 

lam'ina,  173. 


568 


INDEX. 


Neu'ral  spine,  173. 

Neurol'ogy,  general  considerations,  369, 398. 

Nichols,  William,  48. 

Nictita'ting  membrane,  515. 

NIPPERS  (bone),  02,  67,  534. 

care  of,  74. 

cross-cutting,  68. 

figures  of,  62-63. 
NOMENCLAT'URE,  inconsistencies  of  in 
this  book,  19. 

or  terminology,  10. 
Nomina  impudi'ca,  objections  to,  15. 
Non-medullated  nerves,  399. 
NORMAL  POSITION,  21. 

of  limbs,  37. 
Nose,  nasus,  513. 
NOTES,  cost  of  material  for,  50. 

distribution  of,  48. 

elimination  of,  47. 

proper,  47. 

slip  system  of,  45. 

storaf^e  of,  48. 

subdivision  of,  48. 
Nu'cleus  cauda'tus,  stria'tura,  488. 
Numbering  the  cranial  nerves,  505. 

O'bex  {Latin,  an  obstacle),  482. 
OBLIQUE  lines,  35. 

muscles  of  the  eye,  517-518. 
Obtura'tor  fora'men,  167. 
Occip'ital  con'dyle,  183. 
Oc'ulo-mo'tor  nerve,  507. 
OC'ULUS  {Latin,  the  eye),  eye  and  its  ap- 
pendages, 514. 

fro7;en  sections  of,  523. 

hardening  in  alcohol  for  study,  521. 

images  formed  by,  520. 

muscles  of,  516. 

section,  figure  of,  523. 

tunics  or  coats  of,  521. 
Odon'toid  process  of  axis,  172. 
Odors,  perception  by  olfactory  nerves,  513. 
(Esoph'agus,  gullet,  308. 
Of  and  From,  use  of  with  adverbs,  27. 
Oil-stone,  coarse  and  fine,  77. 
Oiler,  68,  535. 

Olfac'tion,  olfactory  sensibility,  smell,  513. 
OLFACTORY  fossa,  186. 

lobe  or  bulb,  481,  487. 

lobes,  examination  of,  450. 

nerves,  distribution  to  the  nose,  513. 

nerve  or  tract,  476. 
Oli'va  {Latin,  an  olive),  area  elliptica,  482. 
Omen'tum,  278,  280. 
Ophthalmic  (1st)  division  of  the  trigeminus 

nerve,  508,  510. 
OPTIC  chiasma,  475. 

nerve,  origin,  507. 

tract,  490. 
Op'ticus  (lo'bus),  482. 
O'ra  serra'ta  {Latin,  serrated  border),  522. 
Orb'ital  fossa,  180. 
Orb'ito-sphe'noid  bone,  181. 


Organon'ymy  {opyuvov,  an  organ,  and  uvojua, 

a  name),  designation  of  organs,  14, 
ORGANS,  determining  volume  and  capacity 
of,  135-136. 

of  hearing,  526. 

of  sense,  511-533. 
Or'ganum   {Latin  and  Greek,  an  organ  or 

instrument)  audi'tus,  ear,  and  diagram 

of  parts,  526. 
Orific'ium  auric' ulo-ventricula' re,  329. 
ORIGIN  and  insertion  of  muscles,  195. 

more   important  for    determination  of 
muscular  homologies,  196. 

of  the  muscles  of  the  eye,  519. 

of  the  slip  system,  52. 
OS  alisphenoi'deum,  181. 

basioccipita'le,  181. 

basisphenoi'deum,  181. 

cotyloi'deum,  168. 

ethmoturbina'le,  187. 

fron'tis,  181. 

innomina'tnm,  168. 

interparieta'le,  181. 

juga'le,  181. 

lachryma'le,  181. 

lenticula're,  529. 

mala're,  181. 

maxilla' re,  181. 

mes3tlimoi'deum,  187. 

nasa'le,  181. 

orbito-sphenoi'deum,  181. 

palati'num,  181. 

parieta'le,  181. 

periot'icum,  181. 

pla'num,  181. 

praemaxilla're,  182. 

pu'bis,  1G8. 

supraoccipita'le,  181. 

tempora'le,  181. 

vo'meris,  187. 

zygomat'icum,  181. 
Ossic'ula  audi'tus,  bones  of  the  ear,  528. 
Osteol'ogy,  149-191. 
Ova'rium,  ovary,  296. 

Pacinian  Corpuscles,  281. 
PACKING  alcoholic  specimens,  129. 

instruments  for  transportation,  75. 
Pagenstecher,  37. 
Pail,  waste,  81. 
PAIRED  and  azygous,  meaning  of,  33. 

or  lateral  organs,  43. 

organs,  33. 
PAL'ATE  bone,  181. 

soft,  304,  307,  512. 
Pal'pebra  {Latin,  an  eyelid)    dorsalis,  514, 

526. 
Pan'creas  and  figures  of,  278,  287,  288. 
PANCREAT'IC  DUCTS,  288,  290. 

in  man,  and  figure,  292. 

lesser,  290. 

principal,  290. 

reservoir,  289-290. 


INDEX. 


569 


Papil'lse,    fun'giform    and    circum vallate, 

305,  513. 
Paramas'toid  {rcnpd,   by  the    side    of.   and 

fiaaroeuh'/c,  resembling  a  nipple),  185, 
PARCHMENT  for  labels,  68. 

numbers,  68. 
Pari'etal  bone,  181. 
Paroccipita'lis   {~opu,  by  the   side   of,   and 

Latin,  occipttt,  the  back  of  the  head), 

proces'sus,  185. 
Paroccip'ital  process,  185. 
Parot'id  gland.  301. 
Pars  oil  ia'ris  ret'inse,  522. 
Parting  hair  for  incisions,  143. 
PARTS  in  series,  43. 

of  a  muscle,  195. 
Patel'la,  40. 

PATTERN  of  the  cerebral  fissures,  constant 
characters,  501. 

of  the  fissures,  variable  characters,  502. 
PECTORAL  muscles,  figure  of,  234. 

ridge  of  the  humerus,  159. 
Pec'toralis  group  of  muscles,  general  con- 
siderations, 235. 
Ped'icle  of  a  vertebra,  173. 
PEDUN'CULUS  (Latin,  a  small  foot)  me- 
dius,  medipedunculus,  481. 

cerebel'li  inferior,  postpedunculus,  484. 

cerebel'li  superior,  praepedun cuius,  485. 

cer'ebri,  cms  cerebri,  476. 

cona'rii,  habena,  479. 
Pel'vic   bone,   determination  of  right  and 

left,  150. 
Pel'vis  and  figure  of,  167,  168. 
Pericar'dium,  317,  321,  339,  362. 
Perimysium  {Trepi,  around,  five,  a  muscle), 

272. 
Perineu'riura  {irepi,  around,  vevpov,  a  nerve), 

398. 
Perios'teum,  attachment  of  muscles  to,  195. 
Periodic  {nepi,  around,  and  ovg,the  ear),  181. 
Periph'eral,  use  and  significance,  26. 
Peritone'al  sac,  279. 
PERITONEUM,  277,  279. 

and  viscera,  diagram  showing  relations 
of.  279. 

structure  of,  280. 
Permanganate  of  potash,  83. 
Pe'ro  (Latin,  a  rawhide   boot)  olfactorius, 

483. 
Pes  olfacto'rius,  483. 
Petit,  canal  of,  in  eye,  526. 
Phalan'ges,  41. 
Phar'ynx,  307,  Fig.  88. 
Philistinism,  anatomical,  forms  of,  204, 
Philosophical  Society,  American,  vi,  461. 
PHYSIOLOGICAL  and  topographical  po- 
sition,  285. 

sense,  use  of  words  in,  44. 
PI'A  MA'TER  (Latin,  pius,  tender,  mater, 
mother),  483. 

interior,  478. 

removal  from  brain,  429. 


Pigeon  hole  case  and  figure  of,  51. 

Pi'li  tac'tiles,  513. 

Pineal  body,  conarium,  476. 

Pisifor'me,  41. 

Pithing  a  frog,  figure  of,  536. 

Pituitary  body  (hypophysis),  480. 

Planes  of  the  body,  and  fig  are  of,  33,  34. 

Plaster  casts  of  medicornua,  porta,  etc  ,  458. 

Plaster  of  Paris  injection  mass,  139,  140. 

Plates  of  the  brain,  explanation.,  461-471. 

Plat'etrope    (ttMtoc,    breadth,    width,    and 

TpETTEiv,  to  turn),  lateral  homologue,  fel- 
low of  the  opposite  side,  32. 
Pleu'ra,  44,  309,  339. 

PLEX'US  CHOROI'DEUS  infe'rior,  meta- 
plexus,  482. 

me'dius,  diaplexus,  477. 

ventric'uli  lateralis,  proplexus,  485. 

ventric'uli  terlii,  diaplexus,  473. 

ventric'uli  quarli,  metaplexus,  482. 
PLEX'USES  and  tel«,  370,  407. 

not  in  procoelia  of  frog,  422. 

of  brain,  414. 

of  brain,  injection  of,  436. 
Pli'cae  cilial-is,  522. 
Pneumogaslric  or  vagus  nerve,  509. 
Poisoning  dried  preparations,  134. 
Polishing  instruments,  75. 
PONS  cerebelli,  483. 

Tarini,  484. 

(Varo'lii),  483. 
PORTA  (Latin,  a  door),  foramen  of  Monro, 
421,  454,  483. 

and  aula,,  407,  454. 

demonstration,  454. 

existence  demonstrated  by  plaster  injec- 
tion, figures,  458,  459. 
PORTFOLIO  for  sheets,  51. 

for  slips,  48. 
POR'TIO  depres'sa  (praeperforali),  483. 

diencephallca  (cru'ris  cer'ebri),  483. 

m€sencephal'ica  (cru'ris  cer'ebri),  483. 

prom'inens  (praeperfora'ti),  483. 
Portiplex'us  (Latin,  porta,  a  door,  and  plexus, 

a  plaiting  or  braiding),  483. 
POSITION  AND  DIRECTION,  designation 
of,  20,  34,  35. 

on  the  soma,  31. 
Position  in  a  physiological  sense,  44. 
POSTCA'VA,  ve'na  ca'va  inferior,  329,  331, 
356. 

injection  of,  147. 
Postcommissu'ra  (Latin,  post,  behind  [cau- 

dad  ofj,  and  commissura,  a  connection), 

484. 
Postcor'nu  (Latin,  post,  and  cornu,  a  horn), 

484. 
POSTE'RIOR  fissure  of  the  spinal  cord,  478. 

white  column  of  the  spinal  cord.  475. 
Postgeniculalum  (Latin,  post,  and  genicu- 

lum,  a  little  knee),  484. 
Postna'ris  (Latin,  post,  and  naris,  a  nostril), 

513. 


570 


INDEX. 


Postop'ticus  (Latin,  pofit,  and  Greek  onTLKor, 

relating  to  sight),  484. 
Postpedun'culus  (Latin,  post,  and  peduncu- 

lus,  a  littb  foot),  484. 
Postperfora'tus  (Latin,  post,  and  perforare, 

to  bore  tlirougli),  484. 
Postzygapoph'ysis  (Latin,  post,  behind,  l^vyov, 

a  yoke  or  junction,  utto,  from,  and  (pvecv, 

to  grow,  173. 
Potassium  permanganas,  83. 
Pouparti,  ligamentum,  143. 
Practical  suggestions  for  dissectors,  201-203. 
Praeca'va,   for  v.   cava,  superior,  329,  331, 

449. 
PR^COMMISSU'RA    (Latin,    prcB,    before 
[cephalad  of],  and  commissura,  a 
connection),  484. 

demonstration,  457. 
Praecor'nu  (Latin,  prm,  and  cornu,  a  horn), 

454,  484. 
Prsegenicula'tum  (Latin,  proB,  and  genicu- 

lum,  a  little  knee),  484. 
Praena'ris  (Latin,  prce,  and  narls,  a  nostril), 

513. 
Praepedun'culus  (Latin,  prm,  and  peduncu- 

lus,  a  little  foot),  485. 
Praeperfora'tus  (Latin,  prm,  and  perforare,  to 

bore  through),  485. 
Praezygpoph'ysis  (Latin,  prm,  and  l^vyov,  a 

yoke  or  junction,  and,  from,  and  ^vetv, 

to  grow),  173. 
PRECAUTIONS  against  dissection  wounds, 
85. 

against  fire,  114. 

for  cleanliness,  comfort,  and  health,  81. 
PREPARATION  of  bones,  103-111. 

of  ducts  of  salivary  glands,  298. 

of  hollow  viscera,  132. 

of  natural  skeletons,  108. 

of  skulls,  107. 

provisional,  of  specimens,  121. 
PRESERVATION  of  amphibian  brains,  418. 

of  brain,  429. 

of  heart  in  alcahol,  321. 
PRIMARY  divisions  of  the  body,  29. 

divisions  of  spinal  nerves,  372. 
PROCES'SUS  clava'tus,  clava,  475. 

e  cerebel'lo  ad  medul'lam  oblonga'tam, 
postpedun' cuius,  484. 

e  cerebel'lo  ad  pon'tem,  medipedun'cu- 
lus,  481. 

e  cerebel'lo  ad  tes'tim,  praepedun'culus, 
483. 

odontoi'deus,  172. 

paroccipita'lis,  185. 
PROCOE'LIA  {-^rpo,  before  [cephalad  of],  and 
lioi'/ua,  a  hollow),  421,  485. 

and  rhinocoe'lia,  demonstration  of,  454. 
Proof  spirit,  115. 
Proplex'us  {rcpo,  before,  and  Latin,  plexus,  a 

twining  or  plaiting),  454,  485. 
Propodial'ia  (^rpo,  before,  and  'Kovr,  a  foot), 

41. 


PROSENCEPH'ALON  (yrpof,  in  addition  to, 
besides,  ev,  within,  and  /cf^aAr/,  the 
head),  cerebrum,  475,  485. 

of  frog,  420. 
Protuberan'tia  basila'ris,  pons,  483. 
Provisional  preparations,  121. 
Prox'imal,  use  and  significance,  25. 
Psalte'rium  {Latin,  a  harp),  lyra,  481. 
Pseudo-coe'lia   {i{jFv6//g,   false,   and  KoiMa,  a 

hollow),  fifth  ventricle,  485. 
Pseudo-commissu'ra    of  olfactory  lobes  in 

frog  and  other  Anoura,  420. 
PU'BIC  bone,  108. 

symphysis,  169. 
Pul'mo,  lung,  310. 
Pul'monary  artery,  326. 
PUPIL  and  iris,  520. 

form  in  the  cat,  520. 
Putnam,  J.  Pickering,  5. 
Pylo'rus,  282. 
PYR'AMIS,  anterior  pyramid,  485. 

posterior,  clava,  475. 

Quad'rans  (Latin,  a  fourth  part),  486. 
Quadrigem'inum  {Latin,  four  or  four  fold), 
op'tici  and  postop'tici,  439. 

Ra'dius,  40. 

determination  of  right  and  left,  150. 
RADIX   {Latin,  a  root),  exter'na,  external 
root  of  the  olfactory  tract,  486. 

interme'dia  (cruris  olfactorii),  486. 

inter'na,  inner  or  internal  root  of  the 
olfactory  tract,  486. 

latera'lis  (cruris  olfactorii),  485. 

mesa'iis  (cruris  olfactorii),  486. 

moto'ria  (nervi  trigemini),  486. 

senso'ria  (nervi  trigemini),  486. 
Ra'mi  intesti'ni  ten'uis,  359. 
Ra'mus    {Latin,  a    branch),   mandibularis, 

188. 
Razor  strop,  78. 

Readers'  and  Writers'  Economy  Co.,  46. 
REASONS  for  selecting  the  cat,  55. 

for  giving  prominence  to  the  viscera, 
58. 

for  treating  only  part  of  the  body,  57. 
Receptac'ulum  chy'li,  364. 
RECES'SUS  au'li,  486. 

opticus,  480. 

prseponti'lis,  586. 
Rec'tura,  285. 

Rec'tus  muscles  of  the  eye,  517-519. 
Recurrent  laryngeal  nerves,  figure  of,  394. 
Reduction  of  alcohol  with  water,  116. 
REFERENCES,  use  of  slips  for,  47. 

to  books  and  authors,  how  made,  2-3. 

to  other  publications,  reasons  for,  2. 
Re'flex  nervous  centre,  371. 
Re'gio  au'lica,  486. 
Regions  of  the  vertebral  column,  170. 
Reissner's  membrane.  533. 
Relation  of  cavities  of  the  brain,  413. 


INDEX, 


571 


Relative  positions  in  an  animal,  and  names 

for,  17,  35. 
REMOVAL  of  brain,  428. 

of  dura  (mater),  428. 

of  heart,  319. 

of  pia  (mater)  from  brain,  429. 

of  bkin  for  muscles,  205. 

of  the  tail,  102. 
REN,  kidney,  278,  294. 

section,  293. 
Restifor'me  (corpus),  486. 
Restibra'chium,  postpedun'culus,  484. 
Re'te  muco'sum,  512. 
RET' IN  A,  522. 

its  ora  serrata  and  pars  ciliaris  retinae, 
522. 
RHINOC(E'LIA  {(ilc,  the  nose,  KOLlia,  a  hol- 
low), 454,  487. 

and  procoelia,  demonstration  of,  454. 

examination  of,  454. 
RHINENCEPH'ALON    ((>k,  the    nose,   hv, 
within,  Ke(pnA7J,  the  head),  450,  487. 

examination  of,  450. 

of  Amphibia,  470. 
RIB,  costa,  167. 

head,  neck,  etc.,  166. 

figure  of  a  pair  of,  166. 

joints  of,  165. 
Right  and  left,  determination  of,  149, 151. 
Right  heart,  828. 
Ri'gor  mor'tis,  removal  of,  205. 
Ri'ma,  great  transverse  fissure,  487. 
Ri'pa,  488. 
Ros'trum,  488. 
Rouge  for  polishing,  76. 
Roval  Society's  Catalogue,  3. 
RUBBER  gloves,  68. 

tubing,  GS. 
Rudd,  W.  N.,  73. 

Sa'crum,  169. 
Sag'ittal  suture,  183. 
SALIVARY  GLANDS,  297,  298. 

and  ducts,  exposure  of,  299. 

figure  of,  300. 
Sarcolem'ma,  272. 
Saw,  care  and  figure  of,  68,  74. 
SCA'LA  tym'pani,  530,  533. 

vestib'uli.  530,  538. 
Scales,  weighing,  68. 

SCAL'PELS  and  cutting  instruments,  care 
of,  74. 

figures  of.  66,  69. 

figures  of  ways  to  hold,  199,  200. 

how  to  hold,  199. 
Scaphoi'des,  41. 
SCAP'ULA,  description  of,  152. 

determination  of  right  and  left,  150. 

figures  of,  154, 155. 
Schneiderian  membrane  of  nose,  513. 
SCISSORS,  and  figures  of,  63,  70. 

care  of  and  sharpening,  74,  79. 

how  to  use,  200. 


Sclerotica  {gkItjpq^,  hard),  521. 

Seba'ceous  glands,  512. 

Seeker,  tracer,  72. 

Segmen'tal     arrangement     of     encephalic 

names,  409,  446. 
SEG'MENTS  of  brain,  494. 

of  limbs,  40. 
Semicir'cular  canals,  530. 
SEMILU'NAR  valves  and  figure  of,  331, 
347. 

valves,  situation,  338. 
Sense  organs,  511-533. 
Sensibil'ity,  general,  511. 
SEN'SORY   and  motor  nerves  and  roots, 
370,  372,  505,  506. 

nerves,  two  great  divisions,  506. 
Separation  of  heart  from  lungs,  320. 
Sep'ta  of  heart,  329. 
Ssp'tal  area  of  brain,  473. 
SEP'TUM  auricula're,  329. 

Iti'cidum  cer'ebri,  488. 

mediastina'le,  309,  339. 

thorac'is,  809. 

tympan'icum,  528. 

ventricula're,  329. 
Series,  enumeration  of  parts  in,  43. 
Sero'sa  of  heart,  341. 
Sharpening  instruments,  76. 
Sharpness,  determination  of,  78. 
Shepard  and  Dudley's  Catalogue,  59. 
Sight,  vision  or  visual  sensibility,  511,  514. 
Simple,  ideal  brain,  figures  of,  408. 
Sinis'tral  and  dextral,  use  of,  24. 
SrNUS  corona'Iis,  330. 

frontalis,  183. 

of  cardiac  vein,  330. 

of  heart,  329. 

of  Valsalva,  situation  of,  330,  338. 

sphenoida'lis,  187. 
Skel'eton  seen  from  left,  figure  of,  88. 
Skel'etons,  natural,  preparation  of,  108. 
SKIN,  cutis,  appendages  of,  512. 

coloring  matter,  512. 

cutting  the,  204. 

removal  for  muscles,  205. 

structure  of,  512. 

skinning,  three  methods  of,  205. 
SKULL,  173. 

articulations  of  bones,  176. 

base,  figure  of,  182. 

cleaning  of,  107. 

disarticulating,  109. 

doisal  aspect,  figure  of,  180. 

figure  of  hemisected,  186. 

Table  of  bones,  174. 

Table  of  its  foramina,  190. 
SLIP  box,  50. 

portfolios,  48. 

system  of  notes,  45-52. 
SLIPS,  accumulation   and   elimination  of, 
47. 

use  of,  51. 
Small  intestine,  278,  283. 


512 


INDEX. 


Bmell,  olfactory  sensibility,  olfaction,  511, 

513. 
Snowden,  Catalogue  of,  59. 
Soft  palate,  513. 

SO' MA  {aojjua,  the  body),  and  its  divisions, 
36. 

axial  part  of  body,  15,  29. 
SOmmerinor,  505. 
Specific  gravity  hvdrometer,  114. 
SPECIMENS,  dishes  and  boxes  for,  126- 
127. 

display  of,  129. 

for  injection,  141. 

jars,  figures  of,  127. 

storage  and  exhibition  of,  125-126. 

transportation  of,  129. 
Spec'ulum,  sep'tum  luci'dum,  488. 
Spencer,  194. 
Spermat'ic  cord,  143,  297. 
Sphenoid'al  si'nus,  187. 
Spigelian  lobe  of  the  liver,  286. 
Spi'na  neura'lis,  173. 
SPI'NAL  cord,  myelon,  372,  482. 

nerves,  373. 
Spi'ral  lam'ina  of  cochlea,  529. 
Spleen,  splen,  278. 
Sple'nium,  488. 
Sponges,  70, 

Sta'pes,  stirrup,  bone  of  the  ear,  529. 
Sfcenon's  duct,  and  preparation  of,  298,  301. 
Sternum,  figure  of,  163. 
STOM'ACH,  preparation  and  drying,  132. 

and  duodenum,  figure  of,  281. 
Stom'achus,  stomach,  277,  282. 
Stom'ata  of  lymphatics,  316. 
STORAGE  and  exhibition  of  alcoholic  spe- 
imens,  125. 

of  notes,  48. 

temporary,  of  specimens,  125. 
STRI'A  longitudina'lis,  488. 

Lancisi,  488. 
STRIA'TUM  (Latin,  striare,  to  mark  with 
grooves  or  channels),  488. 

exposure,  etc.,  456. 

supposed  representative  in  frog,  421. 
Stropping  instruments,  78. 
Structural  relations  of  certain  fissures,  497. 
STRUCTURE  OF  the  heart   and  vessels, 
362-363. 

large  intestine,  285. 

liver,  287. 

mouth,  304. 

lung,  311. 

muscle,  272. 

nervous  matter.  398-399. 

oesophagus,  308. 

ovary,  296. 

Pacinian  corpuscles,  281. 

pancreas,  293. 

peritoneum,  280. 

salivary  glands,  303. 

small  intestine,  284. 

stomach,  283. 


STRUCTURE  of  the  tongue,  304. 

trachea,  308. 

urocvst,  295. 

uterus,  290. 
Stubs's  nippers,  68. 
Subdivisions,  muscular,  195. 
Sublin'gual  gland,  302. 
Submax'illary  gland,  302. 
SUL'CUS  {Latin,  a  furrow)  habe'nse,  489. 

intercrura'lis  lateralis,  489. 

intercrura'lis  mesa'lis,  489. 

lim'itans,  456.  489. 

triradia'tus,  489. 
Sulphate  of  iron  as  a  deodorizer,  83. 
Superior  articulating  process,  173. 
Supracon'dyloid  foramen,  160. 
Supraoccip'ital    (Latin,   supra,  above,    and 

occiput,    the  back  of  the  head)  bone, 

181. 
Suprare'nal  capsule,  295. 
Sur'cingle  (canda  striati  of  brain),  474. 
Surgeon's  knot,  144,  Fig.  41. 
SUSPENSORY  LIGAMENT  of  the  lens, 
523. 

of  the  urinary  bladder,  294. 
SUTU'RAcorona'lis,  183. 

lambdoida'lis,  183. 

sagitta'lis,  183. 
Sut'ures  of  the  skull,  174,  176. 
Sweat  glands,  512. 
Swift  Manufacturing  Co.,  75. 
Syl'vian  fissure,  its  constancy,  etc.,  498,  501. 
Symmetry,  43. 

Sympathet'icus,  sympath'icus,  369,  392. 
SYMPATH'IC  and  vagus  nerves,  figure  of, 
366, 392. 

nervous  svstem,  369,  394. 
SYMPATH'ICUS  {aiv,  with.  Traitor,  suffer- 
ing), sympathet'icus,  369,  394. 

in  sections  of  thorax,  341. 
SYM'PHYSIS  men'ti,  189. 

pu'bis,  169. 
Synonymy  of  muscles.  Table  of,  207. 
SYRINGES,  use  and  care  of,  137. 

figures  of,  138, 139. 
Syrin'gotome,  figure  of,  66,  71. 
TABLE    illustrating     the    subdivision    of 
notes,  49. 

of  bones  of  skull,  174. 

of  cranial  nerves,  origin,  exit,  distribu- 
tion and  function,  510. 

of  fissures,  ^vith  synonyms,  496. 

of  foramina  of  the  skull,  190. 

of  metric  measures,  5. 

of  names  and  synonyms  of  encephalic 
segments,  405. 

of  parts  of  Amphibian  brain,  409. 

of  parts  of  heart,  322. 

of   physiological    arrangement   of    the 
cranial  nerves,  506. 

of  principal  divisions  of  body,  39. 

of  synonymy  of  muscles,  207. 

of  synonyms  of  cranial  nerves,  505. 


INDEX. 


573 


TABLE  of  systemic  arteries  of  tlie  trunk  and 
arm,  843,  844. 

of  thorac'ic  veins,  342. 

showing  three  methods  of  enumerating 
the  arched  gyri,  501. 
TACTILE  hairs,  512. 
(  sensibility  of  tongue,  513. 

sensibility,  taction,  toucli,  511,  513. 
Tac'tion,  touch,  tactile  sensibility,  512. 
Tae'nia  hippocam'pi,  fim'bria,  478. 
Tags  for  labels,  71. 
TAIL,  relation  to  body,  25. 

removal  of,  102. 
Tailing  to  be  avoided  in  dissection,  203. 
Tape'tum  {ruTTyc,  a  carpet),  522,  526. 
TAR'SUS  and  car' pus,  41. 

comparison  with  man,  41. 
Taste,  gustation,  gustatory  sensibility,  511, 

512. 
Tear  glands,  515. 

TECHNICAL  TERMS  compared  with  ver- 
nacular, 16,  17. 

desirability  of  retaining,  15. 

necessity  for,  16. 

of  myology,  194-197. 
Teeth,  fastening  in  the  skull,  107. 
TE'LA  {Latin,  a  web),  414. 

and  plexuses,  407. 

choroi'dea  infe'rior,  metate'la,  482. 

of  brain,  414. 
Teleol'ogy,  56. 
TEM'PORAL  bone  and  fossa,  180,  181. 

crest,  179. 
Tem'poro-auric'ular  division  of  the  trigemi- 
nus nerve,  301. 
Tem'poro-fa'cial  division    of   the    facialis 

nerve,  301. 
Tenac'ulum,  71. 
TENDON,  195,  272. 

of  the  diaphragm,  311. 
Tensor  tympani  muscle,  528,  538. 
TENTO'RIUM  (LoMn,  something  stretched 
out,  a  tent),  307. 

bony,  of  cat,  187. 

bony,  removal,  428. 
Ter'ma  {rspjua,  a  limit,  a  terminus),  lamina 

terminalis.  422,  489. 
Terminological  changes,  limits  of,  18,  180. 
TERMINOL'OGY,   general    considerations, 
11. 

or  nomenclature,  10. 
TERMS  applying  to  whole  body,  26. 

of  position  and  direction,  20. 
,         technical,  of  myology,  194-197. 
<  Tes'tis,  297. 
Tes'tis  cer'ebri,  postopticus,  484. 
Testu'do  {Latin,  a  tortoise  shell),  479. 
Thalamenceph'alon  {(}u7Mp.o^,  a  bed,  h,  with- 
in, Ke(j)ahj,  the  head),  diencephalon,  477. 
TIIAL'AMUS  ner'vi  op'tici,  490. 

op'ticus,  489,  490. 
Thermometers,  comparison  and  reduction  of 

scales,  8-4. 


THIRD  eyelid,  and  action  of,  515. 

ventricle,  and  aula,  472. 
THORAC'IC  ducts.  368. 

ducts,  figure  of  the  left,  366. 

nerves,  372. 

or  dorsal  vertebrae,  and  determination, 
170. 

transection,  102. 
THO'RAX,  37,  308. 

figures  of  a  frozen  transection,  341. 

figure  of  ideal  transection,  48. 

frozen  sections,  838-842. 

transection    showing  relation    of   sym- 
pathic  and  spinal  nerves,  figure  of, 
397. 
Thread  and  twine,  linen,  61. 
Thy 'm  us  body,  809. 
THY'ROID  axis,  353. 

body,  234. 

or  middle  cervical  ganglion,  395. 
Tib'ia,  determination  of  right  and  left,  151. 
TONGUE,  lingua,  512. 

nervous  supply,  513. 

papilla  of,  806,  807,  518. 

tactile  sensibility,  513. 

uses  of  in  speech,  etc.,  513. 
Tools,  carpenters',  71. 
Topon'ymy  (rorrof,  a  place,  ui^n/ua,  a  name), 

designation  of  position  and   direction, 

20,  38. 
Torsion  of  humerus,  not  a])parent   in   cat, 

158. 
Touch,  taction,  tactile  sensibility,  513. 
Towels,  71. 
Trabec'ula  {Latin,  a  small  beam),  of  heart, 

880. 
TRACER,  seeker,  finder,  66,  71,  79. 

how  to  use,  301. 
Tra'chea,  windpipe,  807. 
TRAC'TUS  op'ticus,  490. 

postrhina'lis,  490. 

rhina'lis,  490. 

transver'sus  pedun'culi,  cimbia,  475. 
Tralles,  alcoometer  of,  1 14. 
Transect,  definition  of  term,  197. 
TRANSECTION  (Latin,  trans,  across,  and 
secare,  to  cut),  98. 

abdominal,  how  to  make,  98-101. 

ideal  of  body,  80. 

ideal  of  thorax,  figure  of,  43. 

thoracic,  102, 
Transverse  process  of  a  vertebra,  173. 
Trape'zium,  490. 

Trape'zius  group  of  muscles,  208. 
Trays,  and  care  of,  73,  74. 
Treatment  of  dissection  wounds,  86. 
Treman,  King  &  Co.,  68. 
Tricus'pid  valves,  329,  831. 
TRIE  A' CI  AL  or  trigeminal  nerve,  507. 

nerve,  its  sensory  and  motor  roots.  507, 
508. 
Trigem'inus  or  trifacial  nerve,  its  two  roots, 

507,  508. 


574 


INDEX, 


Tripod  magnifier,  72. 

TROOH'IN    {Tooxog,  anything  spherical   or 
circular),  158,  160. 

the  caudal,  lesser  or  inner  humeral  tu- 
berosity, 160, 
TROCH'ITER  {rpoxk,  a  wheel,  or  anything 
spherical  or  circular),  153,  160. 

the  cephalic,  greater  or  outer,  humeral 
tuberosity.  160. 
Trochlea,  160. 

Trochlea'ris  or  patheticus  nerve,  507. 
Trophic  {TpQ(i>oq,  a  feeder),  centers,  371. 
Tr-ue  skin,  cutis  vera,  corium,  derma,  struc- 
ture and  function,  512. 
Trunk  and  its  divisions,  36. 
Tu'ba  Fallopiana,  296. 
TO'BER  annula're,  pons,  488. 

cine' re  um,  423, 491. 
TUBER'CULUM  (costse),  167. 

Loweri,  330. 
Tuberosity  of  the  ischium,  169. 
TU'NICiEoc'uli,  521. 

vasculo'sa,  523. 
Tunnels,  72. 

Tur'binated  bones,  scrolls  of,  187,513. 
Turner,  H.  W.,  227. 
Turpentine,  spirits  of,  110,  114. 
Tying  vessels,  144,  146. 
TYMPAN'IC  bulla,  185. 

membrane,  527. 
Tym'panum,  middle  ear,  527,  528. 

UL'NA,  40. 

determination  of  right  and  left,  150. 
Unciform,  eminence,  calcar,  473. 
Uncifor'me  (Latin,  uncus,  a  hook,  and/or/wa, 

form),  41. 
UPPER  (dorsal)  eyelid,  514. 

jawbone,  181. 
Ure'ter,  294. 

U'rinary  bladder,  278,  294. 
U'rine,  expelling,  for  cleanliness,  84. 
Urocystls  (ovpov,  urine,  and  kvotic,  a  cyst, 

a  bladder),  278,  294. 
Use  of  dissecting  instruments,  199. 
U'terine  ligaments,  296. 
tj'TERUS,  278,  295. 

horns  or  cornua  of,  296. 

VA'GUS   (Latin,   mgus,  wandering),   388, 
392,  509. 
and  svmpathic  nerves,   figure  of,  366, 

392. 
in  sections  of  thorax,  342. 
or  pneumogastric   nerve,   origin,    etc., 
509. 
VAL'VA  bicus'pis,  330. 
il'eo-caecalis,  284. 
semiluna'ris,  331. 
Thebesii,  331, 
tricus'ois,  331. 
VALVES  of  veins,  347. 
in  veins,  figure  of,  347. 


Val'vula    (Latin,    diminutive    of    'oaha,    a 

valve),  valve  of  Vieussens,  491. 
Variations  of  muscles,  193. 
Vas  deferens,  297. 
Va'sa  chylifera,  364. 

Vas'cular  system, general  considerations, 315. 
VEINS,  character  and  distinction  from  ar- 
teries, 315. 

of  the  abdomen.  Table,  343. 

of  the  thorax.  349. 

of  the  thoraxand  neck,  Table,  342. 

structure  of,  363. 

to  be  injected,  142. 
Velum  pala'ti,  figure,  307. 
VE'NA  adre'no-lumbalis,  356. 

az'ygos,  331.  349. 

bra'chio-cephallca,  s.  inuomina'ta,  349. 

cardi'aca,  331. 

ca'va,  331. 

ca'va  infe'rior,  postcava,  356. 

corona'ria  ventric'uli,  356, 

femoralis,  injection  of,  146. 

gas'tro-epiplolca,  856. 

gas'tro-splenlca,  355. 

hepatlcse,  356. 

ili'aca  commuliis,  357. 

ili'aca  exterlia,  357. 

ili'aca  inter' na,  358. 

illo-lumbalis,  357. 

jugula'ris  exter'na,  350. 

jugula'ris  exterlia,  injection  of,  147. 

jugula'ris  inter'na,  350. 

mesenter'ica  infe'rior,  355. 

mesenter'ica  supe'rior,  355. 

ova'rii,  357. 

pancreat'ico-duodena'lis,  356. 

phren'ica,  356. 

por'tse,  355-356. 

pulmona'rise,  331. 

renalis,  3o6. 

spermat'ica,  357. 

sterna'lis,  349. 

subcla'via,  349. 

subscapula'ris,  350. 

vertebra'lis,  349. 
VEN'TRAL  and  dorsal,  use  of,  24. 

primary  division  of  nerves,  demonstra- 
•      tion,  376. 
VEN'TRICLES  of  brain,  ccelige,  406,  440. 

of  heart,  relative  thickness,  332. 

of  heart,  transection,  figures,  336. 
VENTRIC'ULUS  (Latin,  the  belly,  a  cav- 
ity), commu'nis,  aula,  472-473. 

dexler  of  heart,  332,  337. 

latera'lis,  prccoslia,  485. 

olfacto'rius,  rhinoccelia,  487. 

op'ticus,  s.  mesencephalici,  482. 

quar'tus,  metaccelia,  482. 

quin'tus,  pseudocoelia,  485. 

sinis'ter  of  heart,  332,  338. 

ter'tius,  diacoelia,  477. 
Vernacular  terms  compared  with  technical, 

16,  17. 


INDEX. 


575 


VERTEBRA,  37. 

cervicales,  figure  of,  172. 

figure  of,  178. 
VER'TEBRAL  column,  regions  of,  170. 

ganglion,  395. 

notch,  173. 

ring,  173. 
Ver'tebrate,  figure  of  various  aspects,  30. 
Vertebrarte'rial  (Latin,  vertebra,  and  arteria), 

foramen,  171,  173. 
Vesi'ca  urina'ria,  urocystis,  294. 
VESSELS,  distinguishing  from  nerves,  375. 

how  to  connect  when  severed,  511. 

of  thorax  and  arm  isolated,  347. 
Vestib'ulum  (of  the  ear),  527,  533. 
Vial  for  brain  or  heart,  figure  of,  128. 
Vibris'sae  (Latin,  xibrare,  to  move  quickly  to 

and  fro),  512. 
Virii  of  intestine.  284. 
VIS'CERA,  abdominal, 

and  peritoneum,  diagram  showing  rela- 
tions, 279. 

general  view  of,  276. 

preparation  of,  132. 
Vis'ceral  and  neural  cavities,  32. 
Vision,  sight  or  visual  sensibility,  511,  514. 
Visual  sensibility,  sight  vision,  511,  514. 
Vit'reous  humor,  522. 
Vit'reura    {Latin,  of   or    like   glass),   522, 

526. 
VOCABULARY,  macroscopic  of  brain,  436. 

partial,  of  amphibian  brain,  403. 
Voli'tion,  center  of,  371. 
Volume  of  organs,  determining,  136. 
Vo'mer,  187. 

Ward,  Henry  A.,  536. 


WASTE  pail,  81. 

papers,  73. 

pit,  82. 
Water  for  the  reduction  of  alcohol,  choice 

of,  116. 
Wax  and  tallow  injection  masses,  141. 
Weighing  pan,  69.  [ 

Weight  of  brain,  determined  from  capacity  ( 

of  skull,  191. 
WETTING  bottle,  and  mixture,  72,  73. 

bottle  for  15  per  cent,  glycerin,  figure 
of,  72. 
Wharton's  duct,  and  preparation  of,  298, 

302. 
Whetstone,  coarse  and  fine,  76. 
Whitall,  Tatum  &  Co..  Catalogue  cf,  59. 
WHITE  nervous  matter,  472. 

substance  of  Schwann,  369,  898. 

zone  of  the  eyeball,  521,  526. 
Wickerscheimer's  liquid,   preparation    and 

use,  124. 
Wigglesworth,  E.,  8. 
Wilkinson,  A.  J.,  Catalogue  of,  59. 
Willis,  505. 

Windpipe,  trachea,  307. 
Womb,  uterus,  295. 
Wood  spirit  or  methylic  alcohol,  124. 
Words,  formation  of  compound  and  hybrid. 

28. 
Wounds,  dissection,  85. 
Wyman  on  anatomical  use  of  cat,  56, 

Zinc  chlorid  for  hardening  brain,  435. 
Zona  alba  of  the  eye,  521,  526. 
Zo'nula  Zinnii,  523. 
Zoological  classification,  8. 
Zygomat  ic  gland,  303. 


ADDITIONAL     INDEX 


Many  of  the  terms  here  given  are  paronyms  of  those  in  the  general  index.  The  par- 
onyms are  followed  by  the  abbreviation  par.  and  the  terms  from  which  they  are  derived. 

In  the  case  of  compound  words  which  are  new  or  not  yet  generally  adopted,  the  accent 
is  so  placed  as  to  indicate  their  component  parts,  e.g.,  cen'timeter,  not  centim'eter  ;  dor'- 
simeson,  not  dorsim'eson  ;  ven'trimesal,  not  ventrim'esal. 


After  brain,  400d,  405. 

Air  sacs  of  lungs,  310. 

Al'bal  (adj.  from  alba),  446. 

Al'bicans,  447. 

Alve  oli  of  the  lungs,  310,  311. 

Alveoli  of  teeth,  183. 

Anatomical  landmarks,  95-98. 

Aquseduct'us  Fallo'pii,  181,  190. 

Arachnoi'dal  (adj.  from  arachnoid),  446. 

A'rea  intercrura'Iis.  447. 

Arseniate  of  soda.  111,  112. 

Au'la,  446. 

Aulatele  (par.  of  aulatela),  409,  413. 


Ax' on  {d^o)v,  axis),  30,  fig.  3. 

Callb'sum,  447. 

Centra'le  (Latin,  centralis,  central),  88. 

Cerebel'lo-cor'tex,  446. 

Cerebellum,  447. 

Chi'asm  (par.  of  chiasma),  409. 

Cine' real,  or  fibro-cellnlar,  446. 

Commissu'ra  habena'rum,  447. 

Cona'rium,  447. 

Cook  &  Co.,  manufacturers  of  aicohol,  114 

Cross-references,  3. 

Crus,  447. 


576a 


INDEX. 


Degrease'  {French,    degraisser,    to    remove 

grease  from).  111. 
Deatopsy'che    (devrtpog,    second,  and   -^vxi'i, 

soul),  405. 
Di'acoele  (par.  of   diaccelia),  400d,  408,  409, 

447;  tig.  110. 
Diacoe'liau  (adj.  from  diacoe]e\  447. 
Di'aplex  (par.  of  diaplexus),  409,  447. 
Di'atele  (par.  of  diatela),  409,  447. 
Dien'ceplial  (par.  of  dienceplialon,  400d,  405, 

409,  446,  447. 
Dis'cus  op'ticus,  522,  525. 
Dissection,  methods  of,  201,  299,  342,  375, 

390,  511. 
Dor'simeson     {Latin,    dorsum,    back,     and 

niGov,  the  middle),  25,  28. 
Dropping-tube,  68,  535. 

Ectocu'ueiforme  {tnroc,  external,  and  Latin 

^cuneiformis),  38. 
En'cephal  (par.  of  eucephalon),  400d,  408 ; 

fig.  110. 
Encephalic  flexure,  446. 
Enceph'aloccele     (par.    of     encephalocoelia, 

from   encephalon    and  ncn'/ia,  a  cavity), 

400d,  408,  410,  448 ;  fig.  110. 
Enceph'alomere    (encephalon   and  fiepo^,   a 

part),  410,  446. 
En'dyma,  446-448. 

En'teron  {}:vTtpov,  intestine),  30,  fig.  3. 
Entocoe'lian    (ftrof,    within,    and    Kot/Sa,    a 

cavity).  448. 
Entocu'neiforme  {hToc,  within,  and  Latin 

cnneiformis,  wedge' -shaped),  38. 
EntrencepJiale,  405. 
Epen'cephal   (par.  of  epencephalon),  400d, 

405,  409. 
Epenceph'alon  definiti'vum,  405. 
Ep'icoele  (par.  of  epicoeiia,  q.  v.),  400d,  408, 

409,  446, 447  ;  fig.  110. 
Epipsy'che  {etti,  upon,  and  V^/t'?.  soul),  405. 
Exoccip'ital  (bone),  175,  184. 

Fasci'ola,  448. 

Fastig'ium,  447. 

Fibro-cell ular  or  cinereal,  446. 

Fibula're  {Latin  fihularis,  pertaining  to  the 
fibula),  38. 

Fifth  ventricle  (pseudocoele),  448. 

Fim'bria,  448. 

Fissu'ra  or  fissure  of  the  brain.     See   the 
table,  437. 

Foramen  of  Magendie,  447. 

Forebrain,  400d,  405. 
■^   Forn'ical  (adj.  from  fornix),  448. 
'    Fornicom'missure  (from  fornix  and  commis- 
sure), 449. 

For' nix,  447,  448. 

Fos'sa  glenoi'dea,  156,  184. 

Fos'sa  infraspina'ta,  156. 

Fos'sa  subscapula'ris,  154. 

Fos'sa  supraspina'ta,  156. 

Fos'sa  trochiteria'na,  157. 


Heraien'ceplial  (par.  of  hemi encephalon), 
446. 

Hemisec'tion  (/////,  half,  and  Latin,  secare,  to 
cut),  32,  305  ;  fig.  88. 

Het'eronym  (see  heteronymy,  preface). 

Heteronym'ic  (adj.  from  heteronym,  pref- 
ace). 

Heteron'ymy  {sTEpuvviinq,  the  use  of  words 
having  the  same  meaning  but  not  the 
same  derivation  ;  as,  the  use  of  vernac- 
ular for  classical  names) ;  preface. 

Hia'tus  Fallo'pii,  181,  190. 

Hindbraln,  400d,  405. 

Hinterliirn,  405. 

Hypoph'ysis,  447. 

Hypoth'enar  em'ineace,  387 ;  fig.  105. 

Infundib'ulum,  447. 

Interme'dium  (Xr/^i^i,  intermedins,  between), 

38. 
Intunipscen'tia  lumba'lis,  400d. 
Iter,  446,  447. 

Lar'ynx,  94,  306  :  fig.  101. 

Lateriduc'tion  {Latin,  latus,  side,  ducere,  to 

lead),  217. 
IJn'gula  (diminutive  of  lingua,  tongue),  447. 
Liquid  gelatin,  535. 
Lumbar  enlargement,  400d. 

Max'illo-tur'binal  (bone),  176,  187. 
Medicom'missure  (par.  of  medicommissura), 

446. 
Mer'os  (//?;po' ,  thigh),  38-40  ;  fig.  6. 
Mesen'cephal  (par.  of  mesencephalon),  400d, 

405,  409,  446,  447. 
Mes'occele  (par.  of   mesoccelia),  400d,  408, 

409,  410,  447 ;  fig.  110. 
Mesocu'nei forme  {ptour,  middle,  and  Latin, 

cnneiformis,  wedge-shaped),  38. 
Mesopsy'che  {juaoc,  middle,  and  '^vx''']^  soul), 

405. 
Met'acoele   (par.  of    metacoelia),   400d,  408, 

409,  446,  447  ;  fig.  110. 
Met'aplex  (par.  of  metaplexus),  409. 
Metapsy'che  {/leru,  beyond,  and  ipi'X'?,  soul), 

405. 
Met'atele  (par.  of  metatela),  409,  447. 
Meten'cephal  ([;ar.  of  metencephalon),  400d, 

405,  409,  447. 
Metep'icoele  (par.  of  metepicoelia,  fierd,  after, 

EKt,  upon,  and  noiAia,  a  hollow),  447. 
Mic'ron  {umpdr,  small,  a  term  introduced  by 

Rogers  to  designate  the  thousandth  of 

a  millimeter),  7. 
Midbrain,  400d,405. 
Mittdhirn,  405. 
Mon'onym  {povog,  single,  and  ovvfin,  a  name), 

preface. 
My' el  (par.  of  myelon),  400d,  408,  410,  446  ; 

fig.  110. 
Myelen'cephal     (par.    of     myelencephalon, 

g.  v.),  400d. 


INDEX. 


hlhb 


My'eloccelo  (par.  of  myelocoelia,  fwe/Jjr, 
marrow,  and  kolIIo,  a  cavity),  40Cd, 
408,  410,  446  ;  fig.  110. 

Nnchhmi,  405. 

Navicula're  {Latin,  navicularis,  pertaining  to 

small  ships).  88. 
Neu'roccele   (par.  of  neurocoelia,    vEvpor,    a 

nerve,     and    Koi/Ua,     a    cavity),    400d, 

410. 
Neu'romere   (vevpor,   a   nerve,  and    [ispog,  a 

part),  400d. 
Neu'ron    {yEvpjv,  a  nerve),   80;  4U0d,    410; 

fig.  8. 
Nod'ulus  (dimin.  of  nodus,  a  knot),  447. 

Op'toccele  (par.  of  optocoelia,  for  opticoccelia, 
oTTTtKoc,  OT)tic,  and  KoiAia,  a  cavity),  400d, 
408,  409  ;  fig.  110. 

Par'onym  (see  paronymy),  preface. 

Paronym'ic  (adj.  from  paronym),  preface. 

Paron'yniy  (rrapuvv/un,  the  use  of  words  of 
the  same  derivation  and  meaning),  pref- 
ace. 

Perox'ide  of  hy'drogen.  111. 

Periot'icum  (rtepi,  around,  ovc,  droc,  the  ear), 
175,  187,  530. 

Petro'sum  {n-trpoc,  a  rock),  175. 

Pi'al,  adj.  from  pia,  446. 

Pol'yonym  (n-o/itf,  many,  and  ovdfxa,  a 
name),  preface. 

Pons,  447. 

Por'ta,  447. 

Por'tiplex  (par.  of  porti plexus),  447,  448. 

Postcom'missure  {Latin,  pout,  behind,  cau- 
dad  of  and  commissure),  447. 

Postenceph'alon  {Latin,  post,  after,  and  en- 
cephalon,  q.  v.),  405. 

Postop'ticus,  447. 

Postperfora'tus,  447. 

Preoblonga'ta  {Latin,  prce,  before,  and  ob- 
longata), 447. 

Preop'ticus  {Latin,  pr(e,  before,  and  oTrrtKog, 
pertaining  to  sio^ht),  447. 

Pro'ccele  (par.  of  procoelia),  400d,  408-410  ; 
fig.  110. 

Pros'^n'ceplial  (par.  of  prosencephalon.),  400d, 
405,  409,  446,  447. 

Prosencephal'ic  (adj.  from  prosencephal), 
447,  448. 

Pros'occBle  (par.  of  prosoccelia,  7rp6r,  in  ad- 
dition to,  besides,  and  Koi'Aia,  a  cavity), 
400d,  408,  409,  418.  448  ;  fig.  110. 

Pros'oplex  (par.  of  prosoplexus,  irpnr,  in  ad- 
dition to,  besides,  and  plexus),  409,  447, 
448. 

Prosthenceph'alon  {Trpoodev,  before,  and  en- 
cephalon),  405. 

Protenceph'alon  prima' rium,  405. 

Protenceph'alon  secunda'rium,  405. 

Protopsy'che  {npiJTor,  first,  and  ^^f'r?},  soul), 
405. 


Prototer'ma  (primitive  terma),  448. 
Pseu'docoele  (par.  of  pseudocoelia),  448. 
Pterygoid  (bone),  175,  184. 
Py'la  {rrv?,/},  a  door,  a  narrow  passage),  400d, 

408,  409  ;  fig.  110. 
Pyram'idal  (bone),  161. 

Reces'sus  conarii,  447. 

References  to  publications,  8. 

Rhi'noccele   (par,   of  rhinoccelia,  /5<V,    nose, 

and  KOilia,  a  cavity),  400d,  410. 
Rhom  bocoele  (par.  of  rhomboccelia,  poijfior, 

rhomb,  and  liouia,  a  cavity),  400d,  408, 

410  ;  fig.  110. 
Rhomboid  sinus,  400d. 
Ri'ma,  447,  448. 
Ri'pa,  448. 

Schuyler  &  Co.,  75. 

Sep'tal  area,  448.  ,  - 

Sep'tum  lu'cidum,  448. 

Slips  in  scientific  correspondence,  52. 

Sple'nium,  447. 

Squamo'sum  {Latin,  sqicamostis,  scaly),  175. 

Starch  injections,  140,  141. 

Suben'dymal,  446. 

Syrin'gocoele  (pa-r.  of  syringoccelia,  ovpi)B,  a 

tube,  and  KoiXia,  a  cavity),  400d,  408- 

410 ;  fig.  110. 

Table,  illustrating  the  method  of  reducing 

Latin  yolyonyms  to  mononyms,  of  con- 

vertinpr  Latin  mononyms  into  English. 

paronyms,   and   of   forming   adjectives 

from  the  same.     Preface. 
Table  of  instruments  and  materials,  59-62, 
Table  of  the  neuromeres  and  their  cavities, 

400d. 
Table  of  the  macroscopic  vocabulary  of  the 

brain,  436-438. 
Ter'ma,  448. 

Thal'amic  (adj.  from  thalamus),  448. 
Thar  am  us,  447. 
Tibia'le  {Latin,  tibialis,   pertaining  to   the 

tibia),  38. 
Tu'ber  ciner'eum,  447. 
'Tweenbrain,  400d,  405. 

Val'vula,  447. 

Val'vule  (par.  of  valvula),  409, 

Ve'lum,  447. 

Ven'trimeson     {Latin,    mnter,    belly,    and 

fiEGov,  the  middle),  25,  28. 
Vorderhirn,  405, 

White  &  Burdick,  75. 

Xiphister'num   {^i<pog,   sword,   and    arepvovy 
sternum),  163. 

Zmschenhirn,  405. 
Zygo'ma,  89,  97,  181. 
Zygomat'ic  arch,  181. 


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